From kls Tue Oct 11 12:53:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: avion@blackbird.db.erau.edu (The Avion) Subject: ANNOUNCE: First Aviation Newspaper on the Net! Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:47 Organization: Embry-Riddle Aeronautical University Status: OR The first Aviation/Aerospace Newspaper to be available over the Internet is now being offered. The Avion Online can be read each week at the following URL: http://avion.db.erau.edu/ The Avion Onine is Embry-Riddle's weekly college newspaper that specializes in aerospace/aviation topics. The Space Technology Section routinely covers activity at Kennedy Space Center, including shuttle launches and landings. The Aeronautica Section routinely covers activity in the aviation and aeronautics industry, including aviation trade news and special fly-in events. Get college students' perspectives on the aviation/aerospace industry each week in the Avion Online. -- The Avion Online Newspaper Embry Riddle Aeronautical University The Avion Online avion@avion.db.erau.edu From kls Tue Oct 11 12:53:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Stephen L Nicoud Subject: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:47 Status: OR From: sharam@.cdac.com (Sean Namazi) Message-ID: Date: 29 Sep 94 00:15:37 I'd like to know the validity of the reports on the failure of the 777 P&W engine while being certified for ETOPS. Can anyone shed any light on this? This supposedly occured sometime last week. Aviation Daily reported on September 27 that the PW4000 engine suffered a failure during endurance testing last week. The engine (P008 - eighth production engine) was 700 cycles into a 3,000 cycle ground-endurance test series to clear the 777/PW4000 combo for ETOPS (Extended Twin OPerationS). Ed Crow, a P&W senior VP and chief of PW4000 programs is quoted as saying "There was a failure of two variable vane actuator arms" which help control the movement of variable guide vanes in the engine's compressor. There could be "two weeks, at worst a month, delay to our 3,000-cycle ETOPS testing," he said, but noted that it shouldn't affect the overall 777 test or delivery schedule. The Aviation Daily article gives more details about the failure and about the demanding testing that is being undertaken in order to achieve ETOPS. Stephen -- Stephen L Nicoud bcstec!bcsaic!Stephen.Nicoud This message does not represent the views of The Boeing Company. I am not a spokesperson for The Boeing Company. All rights reserved. From kls Tue Oct 11 12:53:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: C Lowenstein/Product Safety Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:47 Status: OR In Article sharam@.cdac.com (Sean Namazi) writes: > >I'd like to know the validity of the reports on the failure of the >777 P&W engine while being certified for ETOPS. Can anyone shed >any light on this? This supposedly occured sometime last week. > PRATT & WHITNEY'S PW4084 engine should still be approved on schedule for Boeing 777 early twin engine operations [ETOPS], despite the failure of two variable vane actuator arms in the engine during flight operations testing at Pratt's West Palm Beach Florida facility on Sept. 23. (Aviation Week, 10/3) Karl- This was in Av Week. I haven't heard anything else on it. I hope it helps... -Chris. (and vice versa) From kls Tue Oct 11 12:53:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: wolf@accesspt.north.net (Brad Gillies) Subject: Crash Reports Message-ID: Approved: kls@ohare.Chicago.COM Organization: UUNorth's AccessPoint Service Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:47 Status: OR I was wondering if there is anywhere Online I can find information or reports from the NTSB or FAA on crashes of airliners. I am doing a study (personal interest) and would like to know if the reports are obtainable from the NTSB or FAA, I would require all possible info (probable cause, etc.) any help would be greatly appreciated. -- From kls Tue Oct 11 12:53:48 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ngupta@nano.mit.edu (Nitin Gupta) Subject: reverse thrust in flight Message-ID: Approved: kls@ohare.Chicago.COM Organization: Massachvsetts Institvte of Technology Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:48 Status: OR a while ago someone asked if activating reverse thrust during flight in order to reduce speed was a good idea. on subsonic airframes i assume the answer is no since there are control surfaces to trim away speed without having to involve the engines. curiously, the concorde may employ reverse thrust during flight to cut speed. because of it's sleek design, it lacks air brakes and other conventional control surfaces which could be used for speed trimming. instead the two inboard olympus 593 engines reverse thrust while the two outer ones are in forward idle. on landing all four reverse thrust as expected. Flying Concorde by Brian Calvert (ISBN 1853100277) is an excellent presentation of the issues surrounding and practice of supersonic commercial flight. blue skies --------------------------------------------------------------------- Nitin Gupta MIT NanoStructures Laboratory ngupta@nano.mit.edu NeXT Mail Encouraged 617 253 0722 --------------------------------------------------------------------- From kls Tue Oct 11 12:53:48 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: allard@iconz.co.nz (David Allard) Subject: extended range twin engine operations Message-ID: Approved: kls@ohare.Chicago.COM Organization: Internet Company of New Zealand Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:53:48 Status: OR I am interested in communicating with any pilots currently engaged in ETOPS. Areas of interest are enroute alternate criteria,fuel policy and flight planning criteria. David Allard. From kls Tue Oct 11 12:57:25 1994 Newsgroups: sci.aeronautics.airliners,sci.aeronautics.simulation,comp.robotics,misc.transport.urban-transit,sci.engr.advanced-tv,sci.engr.manufacturing,sci.engr.biomed,sci.engr.control,comp.multimedia,comp.os.research,comp.lang.mumps,comp.lang.forth,sci.military Path: bounce-back From: baker@grep.cs.fsu.edu (Ted Baker) Subject: RTAS'95: Realtime Technology & Applications Symposium Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: poster Sender: kls@ohare.Chicago.COM Date: 11 Oct 94 12:57:25 Organization: Florida State University Computer Science Department Status: OR CALL FOR PAPERS =============== IEEE Real-Time Technology and Application Symposium =================================================== May 15-17, 1995 Chicago, Illinois RTAS'94 is the successor to the 11th Workshop on Real-Time Operating Systems and Software. Since the early 80's, we have witnessed an increased interest in real-time technology because of the need for scientific solutions for time-constrained information processing in various applications such as avionics, multimedia, robotics, automated process control, and manufacturing. Founded in 1983, the IEEE Workshop on Real-Time Operating Systems and Software (RTOSS) has been an important annual forum for exchanging information of emerging principles and practices underlying real-time technology. Consequently, we are seeing a substantial number of new researchers tackling the many challenging problems that remain. Due to the interest shown in, and the success of, the RTOSS, the IEEE technical committee on real-time systems has decided to convert RTOSS into a full symposium, the real-Time Technology and Applications Symposium. The purpose of this symposium is to bring together developers and researchers from universities, industry, and government to advance real-time technology and its applications. Papers on all aspects of real-time computing are sought, including operating systems and scheduling, fault-tolerance, databases, programming languages, tools, communication networks, architectures, performance modeling, formal methods, case studies, and applications. Of particular interest are papers detailing experiments and implementations. This year we are planning special sessions in the areas such as Intelligent Vehicle Highway Systems and Multimedia. Papers on these topics are especially encouraged. Manuscripts should be limited to 20 double spaced pages. Papers submitted to the Symposium should not be submitted elsewhere. Six copies of the paper should reach the program chair no later than January 7, 1995. Authors will be notified of acceptance by Feb 28, 1995. Final camera-ready manuscripts will be due by March 31, 1995. Proposals for two-hour tutorials in technical areas of the conference are also solicited. Tutorial proposals should be submitted to the program chair by January 7, 1995. Important Dates =============== Paper submission: Jan 7, 1995 Tutorial proposal submission: Jan 7, 1995 Acceptance notification: Feb 28, 1995 Final camera-ready manuscript: Mar 31, 1995 ORGANIZING AND PROGRAM COMMITTEES General Chair: Ted Baker Department of Computer Science (4019) Florida State University Tallahassee, FL 32306-4019 phone: 904 644-5452 email: baker@cs.fsu.edu Program Chair: Wei Zhao Department of Computer Science Texas A&M University College Station, TX 77843-3112 phone: 409 845-5098 email: zhao@cs.tamu.edu Treasurer: Ted Giering, Florida State University Publicity Chair: Raj Rajkumar, Software Engineering Institute, CMU Local Arrangements Co-Chairs: Jeffrey Tsai, University of Illinois at Chicago Chengwen Liu, DePaul University Ex-Officio: (RTS-TC Chairs) John Stankovic, University of Massachusetts at Amherst Al Mok, University of Texas at Austin Program Committee: Yahya Y. Al-Salqan West Virginia University Sadler Bridge Texas Transportation Institute/TAMU Alan Burns University of York Richard Gerber University of Maryland Prabha Gopinath Honeywell Inc Steve Howell Navy Surface Warfare Center Jiandong Huang Honeywell Inc Arkady Kanevsky Mitre Corporation Doug Locke Loral Federal Systems David Luginbuhl AFOSR Jane Liu University of Illinois at Urbana Steve Liu Texas A&M University Al Mok University of Texas at Austin Kelvin Nilsen Iowa State University Krithi Ramamritham University of Massachusetts at Amherst Lui Sha Software Engineering Institute/CMU Kang Shin University of Michigan John Stankovic University of Massachusetts at Amherst Alexander D. Stoyenko NJ Institute of Technology Lonnie R. Welch NJ Institute of Technology Victor Wolfe University of Rhode Island Hui Zhang Carnegie Mellon University RTAS'95 is sponsored by the IEEE Technical Committee on Real-Time Systems, in cooperation with the Office of Naval Research. From kls Fri Oct 14 02:23:33 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rdd@netcom.com (Robert Dorsett) Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:33 Status: OR In article "Dr. Martin Erdelen" writes: >On 19 Sep 94 01:28:39 Karl Swartz said: >> >>The usual design for a wing-mounted engine intentionally puts the weak >>point in the mount at the rear of the engine. This way, if something >>happens that causes the mount to break, it'll break at the rear. > >Why not making the *front* mount give in so that >engine rotates downwards around rear mount and leaves earthwards with >nothing else in the way (instead of trying to sneak it between wing >and stabilizers)? 1. Most engine designs aren't as "tidy" as the 737-200s, where the engine is neatly tucked under the wing. Many airliners have the bulk of an engine in FRONT of the leading edge, attached via a rather long pylon. It makes sense to have the strongest area where it can resist the pivot moment. 2. As Karl implies, if the engine rotated down and out, it could damage wing control surfaces on the way out, as well as damage the horizontal stabilizer. Strange though it may seem, "up and over" actually does work pretty well. -- Robert Dorsett Moderator, sci.aeronautics.simulation rdd@netcom.com aero-simulation@rascal.ics.utexas.edu From kls Fri Oct 14 02:23:33 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:33 Status: OR In article , Dr. Martin Erdelen wrote: >On 19 Sep 94 01:28:39 Karl Swartz said: >> >>The usual design for a wing-mounted engine intentionally puts the weak >>point in the mount at the rear of the engine. This way, if something >>happens that causes the mount to break, it'll break at the rear. The >>engine then rotates up around the front mount, breaking it too, and >>the residual thrust carries the engine up, over the wing, and out of >>harm's way. (The trajectory is also designed to avoid the horizontal >>stabilizers.) > >Amazing... there seems to be no end to possible design goals. >But, speaking naively (euphem. for ignorantly): isn't this a somewhat >roundabout approach? Why not making the *front* mount give in so that >engine rotates downwards around rear mount and leaves earthwards with >nothing else in the way (instead of trying to sneak it between wing >and stabilizers)? >Just curious. Because if the front mount breaks first, the thrust vector will create a nose-up moment around the rear mount (the thrust line is below the mount) causing the engine to push up against the strut or wing (depending on the level of failure designated) and probably not depart the airplane. In such a position, a thrust-producing engine banging away at the wing could cause considerable damage whether it eventually departed the airplane or not. Given the relative importance of the wing to continuing flight, we airframers tend to prefer a clean breakaway of the engine, and the simplest manner of ensuring this is to design the rear mount to fail first. Let us postulate two possible failure modes. First, the front mount fails first, and the engine continues to run normally. The engine would most likely hammer against the remaining strut until parts of it fail or against the bottom of the front spar if the strut fails totally. This is considered undesireable for those who were wondering. A more innocuous version of that failure would be for the engine to find another equilibrium position using the failed structure above it to transmit those upward loads (which are alleviated to some extent by the weight of the engine). The second scenario is for the front mount to fail, and the fuel lines to crimp and break. The engine will run normally for several seconds as the fuel in the line below the break continues to feed in. The crimped and broken fuel lines will blow exciting amounts of raw fuel into the strut and out into the airflow, causing a truly inspiring white cloud of vaporized fuel to trail the airplane - right above the engine. This would be a severe fire hazard. Both of those scenarios can be avoided by designing the rear mount to fail first, and the engine to break away cleanly afterwards. There are a couple of arugments against designing for this sort of thing. One is that it could be considered poor form to go about deliberately littering the environment with relatively low-time engines which could probably have been economically repaired had they been returned with the airplane itself to the proper repair facility. Some people are simply not comfortable with the concept of sequenced failure. The other argument is that with a deliberately "weakened" mount, you are more likely to encounter inservice problems, the fuse-pin argument, if you will. Understand that the concepts of fuse-pins and sequenced failure of the engine mounts were conceived during the early years of jet transportation when engine failures were more frequent and rather more spectacular than they are today. Perhaps a future airplane design will assume that the engines are so reliable that they "never" (10^-9 probability of failure) fail in such a manner as to endanger the aircraft. We aren't there yet. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: tristar500@aol.com (TriStar500) Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR In article , kls@ohare.Chicago.COM (Karl Swartz) writes: > I believe the USAir incident was blamed in part on a missing or >incorrectly installed retaining cable. I believe this cable was added to the design after the aft cone bolt was found to be a weak spot. There is an AD on the 737-200 that requires a check of the aft cone-bolt about every 25 hours. This cable also broke in the SW 737 incident in DAL a few years ago. The engine remained on the airplane suspended by the two forward cone bolts. >Finally, several instances of 727s losing #1 or #3 come to mind -- AA >from DFW to SAN near the AZ/NM border and NW over northern Florida. >In both cases, the foreign object damage (FOD) to the engine caused >the separation As I recall, these were both number 3 engines and were caused by blue ice from the forward lav service panel. From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: etate@mcl.bdm.com (C. Emory Tate) Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: etate@lan.mcl.bdm.com Organization: BDM Federal, Inc. Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR Not long ago, PBS repeated a NOVA segment about NTSB air accident investigations, featuring Deepak and all the crew, and centering on an investigation of a B737 crash in Panama. Seems that an HSI failure owing to a wiring fault went undetected by the crew, at night with no stars over the boonies. When the pilot rolled out of a turn, the HSI stuck, indicating that the a/c wasn't rolling out on the new heading, so the pilot kept applying opposite yoke. He did such a great job that nobody noticed that they had rolled right 'round the other way... until the HSI unstuck, and they repeated the process in the other direction... several times, in fact, until the plane finally rolled on its back and fell from the sky. Its final flight path was remarkably similar to that of US427 (apparent Dutch rolls into an inverted stall and powered dive), but that's gotta be a coincidence of aerodynamics and control responses, given that the latter happened in day VFR, right? -- C. E. Tate snailmail: BDM Federal, Inc. 1501 BDM Way, McLean, VA 22102 ____________________________________________________________ Happiness is a straight yaw string and an 800ft/min thermal. From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: vac@air16.larc.nasa.gov (Victor A. Carreno) Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NASA Langley Research Center Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR In article , kls@ohare.Chicago.COM (Karl Swartz) writes: |> |> On the other hand, the 737-300 (-400 and -500 too) have a completely |> different pylon design and I've never heard of them losing an engine. |> |> Finally, several instances of 727s losing #1 or #3 come to mind -- AA |> from DFW to SAN near the AZ/NM border and NW over northern Florida. |> In both cases, the foreign object damage (FOD) to the engine caused |> the separation -- the pylon design prefers detachment of a suddenly |> unbalanced engine to destruction of the fuselage. |> I thought this will be of interest: The Washington Post 18JUN93 Breakaway Jet Engine Abandoned Boeing Announces Design Change in 747 The Boeing Co., abandoning a 25-year design theory that letting engines break free under severe stress is safer, yesterday announced major wing modifications to prevent engines from falling off the 747 jumbo jet in flight. The changes, which would take four to five years to implement on the 948-plane fleet, are the latest step in an engineering investigation prompted by the crash last Oct. 4 of an El Al cargo jet into an apartment complex in Amsterdam. [suff deleted] The company essentially acknowledged that it had built the world's most popular jumbo jet for 25 years under the misconception that the planes could always fly after losing engines and that having an engine break away after a catastrophic failure sometimes was safer. "We thought an engine could come off safely," said Dick Johnson, Boeing's director of engineering for the company's 747/767 program. "We've had two accidents since that proved that to be wrong." [more stuff deleted] The modifications follow two paths: strengthening the entire strut assembly including fuse pins, and adding a redundant backup structure that could hold the engine to the wing even if the new fuse pins fail. "We've decided that safe separation isn't the way to go," Johnson said. "So we are going to make sure they don't fall off." Johnson said the new design essentially is the same one used in the newer Boeing 767 and 757 twin-jets. Johnson said the new design would allow the engine to break free if it comes in contact with the ground in a belly landing. Fuse pins now are to be made of stainless steel to prevent corrosion and have a simple straight-bore hole through the middle rather than internal notches. A Cray supercomputer determined that the nothches would cause the pins to undergo stress eight to 10 times greater than expected under load. [end deleted] From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: bd_lerner@gate.pnl.gov Subject: Re: 737 musings References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR As far as the engines flipping over the wing, if the engine is swinging below the wing, isn't there a chance the engine may swing back up into the wing before the rear bolts detach? Incidentally, back to the AA DC-10 crash in Chicago, when the enghine detached, I remember hearing that the engine went above the wing and sliced through the wing's upper skin, cutting all of the redundant hydralics to the elevators. The elevators retracted which resulted in the uncontrolled roll. Also, as far as the AA 727 that loss an engine over NM; it wasn't just any old FOD, it was blue ice from a improperly secured laboratory holding tank door, which is located ahead of the intakes. The aircraft landed in Tucson while I was living there; I remeber the passengers saying that the plane shook somewhat violently and then stopped shaking. The crew had no idea that the engine had torn completely loose. Finally, I know I have seen aircraft fly with one thrust reverser deployed (although I assume with engine thrust cut back); its part of the aircraft certification process so an accidental reverser deployment need not be fatal. Anyway, some musings. Bruce L. OPinions are mine, and not those of PNL, Battelle, or anyone else." From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: rdd@netcom.com (Robert Dorsett) Subject: Re: unpowered glide ratios References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR In article drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) writes: >>For some Boeing planes, or others, what are typical, >>unpowered, sustainable glide ratios? > >Just in general, one can assume a glide ratio in excess of 20 to 1. >The 737 is around 22 to 1, depending on the exact model and configuration. >This is assuming the engines are at idle, or at least windmilling. It does >get worse if they are not turning at all. A friend's training session ended early in an L-1011 simulator, so they er, "experimented." Basically, they shut down their engines when over the final approach fix, in the landing configuration, on speed. They made the runway, setting flaps and flying by the numbers. Assuming a 3 degree glide slope, this would give a 19:1 glide ratio. -- Robert Dorsett Moderator, sci.aeronautics.simulation rdd@netcom.com aero-simulation@rascal.ics.utexas.edu From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: olesen@metronet.com (Eric Olesen) Subject: Re: unpowered glide ratios References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners,rec.travel.air Organization: Texas Metronet, Internet for the Individual 214-705-2901 (info) Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR No, that's me over here! (hedleyj@wl.aecl.ca) wrote: : Wellllll.....I'm certainly no expert on this, but you could use the : 'Gimli Glider' incident as a guide (for Boeing 767-200s anyway). : BTW, if you're ever anywhere where Air Canada are flying their 767s, the : 'Gimli Glider' a/c is tail number 604. Don't expect them to talk about : it too much, though (nor Boeing). Why wouldn't Boeing talk about it? It only proved that even when the impossible occurred, the redundancy of physical controls and the Ram Air Turbine generator performed as they were intended to in the unlikely event of fuel starvation..... And the airframe survived landing on a less than favourable abandoned runway complete with fence posts running down the length of it! Now AC, they should not be talking about it... "Ooops. Screwed up the fuel calculations... only put on half the fuel.... Sorry!" If only they hadn't been so insistent on going metric with the B767's when the rest of the fleet was still using Imperial measurements..... E -- ----------------------------------------------------------------------------- | Eric Olesen | "Views Expressed Do | olesen@metronet.com | | American Airlines, Inc | Not Represent American | Fort Worth, TX | | Ticketing/Terminal Svcs | Airlines or AMR Corp." | Oskee-Wow-Wow | From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: Phil Fernandez Subject: Re: unpowered glide ratios References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Jade and Jett Incorporated Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR In article drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) writes: >Just in general, one can assume a glide ratio in excess of 20 to 1. >The 737 is around 22 to 1, depending on the exact model and configuration. >This is assuming the engines are at idle, or at least windmilling. It does >get worse if they are not turning at all. Is this really accurate that windmilling turbines/fans *increase* the glide ratio on a jet, and get worse if they aren't turning. This is the exact opposite of the result on a prop, where an upowered windmilling prop has near the same drag as a disk of the same diameter. On a prop plane, a stopped prop definitely increasess the glide ratio. What's the scoop? pmf pp-asmel-ia mooney n5632j From kls Fri Oct 14 02:23:34 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rdd@netcom.com (Robert Dorsett) Subject: Re: Fuel Weight versus Initial Cruise Altitude References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:34 Status: OR In article lmassaro@manta.nosc.mil (Larry Massaro) writes: >On a couple of transcon flights, I have noticed that that pilot has >sometimes spoken about leveling off at an intermediate FL to burn >off fuel. Is it really more efficient to burn fuel first at lower >cruise altitudes then climb to a final? Does anyone have any >data/equations etc. which indicate this is true. My first impression >would be that winds aloft would be the more probable reason >for flying at the lower "less eficient" altutude initially. > There are two considerations. The heavier you are, the higher the stall speed gets. Therefore, the heavier you get, the faster you have to go. The faster you go, the closer you'll get to the airspeed limitations of the airplane. At a certain point, the weight vs. speed curves define the maximum altitude of the airplane. The second primary consideration is efficiency. Saturn V didn't haul all its stages to the Moon, and neither does a 747 haul all its fuel to cruise altitude. The less fuel to haul, the more efficient the climb will be, and the more fuel you will save. All this translates into operating econ- omies. Most airliners use a climb to some "initial" altitude. Depending on ATC considerations and the length of the flight (which defines the optimal altitude), the airplane could have several more "steps," which should be pretty much imperceptible to the passengers. Crews attempt to fly to as optimal a flight altitude as possible. It is a common practice. What is bad is when ATC constraints keep an airplane to a low altitude for an unusual period of time. Jockeying for altitude has ramifications on range, ground speed, and overall operating economies and passenger satisfaction. To give an example, here are some values for the 737-200, with JT8D-9 engines. FL = flight level, = altitude / 1000. Schedule is the speed schedule, in Mach. This is a high-speed schedule for the 737, and less efficient. Optimal weight is the computed economical weight for a specific configuration. Limit weight is the cruise thrust limit weight at that al- titude, for ISA+0. FL Schedule Optimal weight Limit weight 370 0.78 75,000 lbs 90,600 lbs 350 0.78 82,000 lbs 99,700 lbs 330 0.78 90,000 lbs 108,500 lbs 310 0.78 99,000 lbs 117,700 lbs 290 0.78 108,000 lbs 120,000 lbs There's a pretty dramatic change there, amounting to two or three hours of flying time, which is probably why one rarely sees these airplanes at FL370. "Winds aloft" enters into the equation to some degree, but the above are the *limits*, regardless of how beneficial the winds turn out to be on flight planning (i.e., fuel load and initial selected altitude for the desired altitude). -- Robert Dorsett Moderator, sci.aeronautics.simulation rdd@netcom.com aero-simulation@rascal.ics.utexas.edu From kls Fri Oct 14 02:23:35 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Alexander Schuetz <100010.1375@CompuServe.COM> Subject: Re: Fuel Weight versus Initial Cruise.. References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: via CompuServe Information Service Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:35 Status: OR > leveling off at an intermediate FL to burn off fuel The most economic FL (called optimum altitude by Boing) differs with gross weight. The B767 for example : Gross Weight 110 tons - 41000ft Gross Weight 180 tons - 30000ft As you burn about 4 to 5 t/h the optimum altitude raises about 700ft/h on the B767. alex From kls Fri Oct 14 02:23:35 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: Fuel Weight versus Initial Cruise Altitude References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: airliners@chicago.com Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:35 Status: OR In article , lmassaro@manta.nosc.mil (Larry Massaro) wrote: > On a couple of transcon flights, I have noticed that that pilot has > sometimes spoken about leveling off at an intermediate FL to burn > off fuel. Is it really more efficient to burn fuel first at lower > cruise altitudes then climb to a final? Does anyone have any > data/equations etc. which indicate this is true. My first impression > would be that winds aloft would be the more probable reason > for flying at the lower "less eficient" altutude initially. > Jet airliners are most efficient flying at a particular Mach number and angle of attack. The values depend upon the aerodynamic design characteristics. Given the desired angle of attack, which of course corresponds to a particular lift coefficient, and the best Mach number, the lift is determined by the ambient air pressure, i.e. the altitude. For steady flight the lift must equal the gross weight of the airplane. Thus the best altitude is determined by the weight, which is constantly decreasing as the fuel is consumed. Ideally the best flight path is a continual climb. From a traffic control standpoint that is impossible, except in regions where the traffic is very light. Thus the optimum climbing flight path is approximated by a step climb where the pilot starts at the best altitude for the initial weight and then climbs to the next higher legal altitude for his direction of flight when the fuel is burned down sufficently. Large changes in wind velocity with altitude may modify the "best" altitude. Other secondary influences are the variation of specific fuel consumption with altitude (usually small) and the variation of the speed of sound (a function of temperature) with altitude, usually zero above 36,150 ft. > Lawrence Massaro > Data Link Research > San Diego, CA 92124 > ------- -- Richard Shevell Email: shevell.leland.stanford.edu From kls Fri Oct 14 02:23:35 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: anderson@williams.edu () Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: James.C.Anderson@williams.edu Organization: Williams College Sender: kls@ohare.Chicago.COM Date: 14 Oct 94 02:23:35 Status: OR >From: Stephen L Nicoud >There could be "two weeks, at worst a month, delay to our 3,000-cycle >ETOPS testing," he said, but noted that it shouldn't affect the overall >777 test or delivery schedule. Couple of questions: 1. What constitues a "cycle." 2. Do the start the testing all over again after a failure like this? Jim -- ******************************************************************************** Jim Anderson Williams College Systems Manager Center for Computing janderson@williams.edu (Internet) Jesup Hall janderson@williams.bitnet Williamstown, MA 01267 413-597-2082 ******************************************************************************** From kls Fri Oct 21 13:47:46 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: d_gooch@pavo.concordia.ca (GOOCH, DANIEL) Subject: Opening a door in flight Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:47:46 Organization: Concordia University Status: OR In response to someone who posted a while back regarding if it was possible to open a door in flight, I just read an article on clari about a guy who tried to open a door on an American MD-11. The article said that a numerical code would have been needed to open the door (huh? I assume this would be ONLY in the air) and that the air pressure at the altitude the plane was at would have kept the door closed. From kls Fri Oct 21 13:47:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Francis.Jambon@imag.fr (Francis JAMBON) Subject: Tarom Airbus: automatic mode switch escaped the commandant's notice Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:47:47 Organization: LGI-IMAG, Grenoble, France Status: OR This is a shortened translation of an article published in Le Monde, date 16-17/10/94, p. 9. Le Monde is considered by many as the major and most-respected french daily newspaper. It always has very documented and accurate reports. Thanks to Francis Jambon for help with the translation of technical terms. In-flight stall of an A310 Airbus An automatic mode switch escaped the commandant's notice The investigation commission shed more light this friday on the incident that involved an A310 of the Tarom airline on the 24th of september over the Orly parisian airport. It appears that the aircraft which was in "landing approach" mode was too fast. This triggered a "mode" switch response from the aircraft. In other words, the aircraft started to go upwards to slow itself down. The aircraft was flying at 364 kilometers per hour (226 mph or 202 knots), slightly over the speed limit of this configuration which is 360 kmph (224 mph or 200 knots). This triggered the automatic response. The pilot tried to counter its effect and thus started a process that provoked the stall of the aircraft. This new information lead the french civil aviation authority (DGAC) to decide to inform immediately the french airlines that use A310s and A300-600s equipped with the same protection mechanism. The DGAC asked the airlines to draw the attention of the crews on the required observation of established speed limits. Airlines should also make sure that the crews are perfectly-well informed of the logics of the protection system that automatically triggers in case of abnormal speed. Disclaimer: I speak for no one and I have no link whatsoever with the companies cited in this message. -- Translated by Daniel Salber, Grenoble, France, Daniel.Salber@imag.fr -- Post by Francis JAMBON - E-mail: Francis.Jambon@imag.fr Interfaces Homme-Machine / Human-Computer Interaction Tel./Phone: (+33) 76 51 48 54 - Fax: (+33) 76 44 66 75 LGI-IMAG, B206, BP 53, 38041 Grenoble cedex 9, France From kls Fri Oct 21 13:47:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: dpearse@magnus.acs.ohio-state.edu (Daniel G Pearse) Subject: Re: New US Air 427 Hypothesis References: Approved: kls@ohare.Chicago.COM Organization: The Ohio State University Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:47:47 Status: OR The Sept. 30 edition of the Columbus Dispatch page A9 has an article titled _737s had rudder problems, report says_. It has an AP article based on an article by the Seattle Times which reviewed 20 years of airline reports submitted to the FAA. No real details are listed. Dan Pearse USPA D6524 From kls Fri Oct 21 13:47:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: "Reply to: philip_decker@lds.loral.com" Subject: Glass Cockpits' Video Rates? Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:47:47 Status: OR Am curious about the characteristics of the video signals displayed in glass cockpit aircraft: sync frequencies, resolution, (non)interlace, etc... Also, are all the displays (vertically) sync'd to each other? Philip Decker [philip_decker@lds.loral.com] Telecommunications Products Loral Data Systems Sarasota, Florida From kls Fri Oct 21 13:47:47 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jkkuchar@ATHENA.MIT.EDU (James K. Kuchar) Subject: Re: Crash Reports References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Massachusetts Institute of Technology Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:47:47 Status: OR In article wolf@accesspt.north.net (Brad Gillies) writes: > >I was wondering if there is anywhere Online I can find information or >reports from the NTSB or FAA on crashes of airliners. >I am doing a study (personal interest) and would like to know if the >reports are obtainable from the NTSB or FAA, I would require all possible >info (probable cause, etc.) >any help would be greatly appreciated. > -- >From WWW, you can get NTSB accident report abstracts at: ftp://rascal.ics.utexas.edu/misc/av/safety-folder/ntsb_abstracts.txt They aren't complete reports, but outline the accident, causes, and recommendations. Jim Kuchar jkkuchar@mit.edu From kls Fri Oct 21 13:49:17 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: news@aol.net Subject: LG wheel hydraulic drive motors Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Oct 94 13:49:17 Organization: America Online, Inc. (1-800-827-6364) Status: OR I saw a paper that had been given at an SAE A6 meeting on the use of hydraulic motors to apply torque though gearboxes to landing gear wheels and thus move the airplane on the ground. This would allow maneuvering the airplane on the ground with only its APU operating to drive a hydraulic pump. Have high torque low speed wheel hub or direct drive motors been considered? These are widely used for off-the-road vehicles, etc. The motors would have to freewheel or be mechanically disconnected during takeoff and landing. Very high torque low speed motors would be required to move a 747 size airplane. The motors would have to be built to aerospace standards of light weight and high strength. Comments? Ideas? Thanks Bill Simpson From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Andrew Chuang Subject: surprise engine order Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR Earlier, Flight International has reported twice that Singapore Airlines would lease eight GE90-powered B777 to replace some of their A310s. However, the news has never been confirmed elsewhere. It's reported in Financial Times that SIA is going to order Rolls-Royce Trent for the B777. This is a bad news for both Pratt & Whitney and GE. Obviously, the recent development difficulties experienced by the GE90 program certainly did not help. For P&W, SIA is the largest PW4000 customer (52 747-400s in service or on firm order, and 17 A310-300s), the order of Trent engines by SIA is not a good sign for the PW4084 program. Korean Air is due to make a decision on engines for their B777s, if KAL orders Rolls, Rolls will catch up with GE and P&W very soon. -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Christopher Isham Subject: Wanted: Info on Airbus Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR The investigative unit at abc news is examining safety record of the Airbus with particular focus on computer/pilot interface issues. We would welcome input of any kind from pilots, mechanics, engineers, aviation inspectors or others with direct experience to contact us at below address. Confidentiality, if wanted, will be respected. ABC News Investigative unit 47 West 66 th st. New York NY 212 456-2400 e-mail: iteam@pipeline.com From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: David Lednicer Subject: Re: unpowered glide ratios References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR As to why a windmilling jet engine produces less drag than a stopped jet engine vs. a stopped prop produces less drag than a windmilling prop: Not much air gets through a stopped jet engine, resulting in very high spillage drag (kinda like holding a coffee mug open end first into the wind). A windmilling jet engine passes more air, reducing the spillage and hence the drag. On the other hand, a stopped prop is usually feathered, which is very low drag. A windmilling prop has more blade surface area exposed and has higher drag. The difference boils down to the fact that the jet engine is contained within a nacelle, while the prop is completely out in the freestream and that the prop has variable pitch, while the jet engine blades are not variable pitch (ignoring variable pitch stators). ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: gparchom@cln.etc.bc.ca (Gale Parchoma) Subject: 747 Fuel Capacity Message-ID: Approved: kls@ohare.Chicago.COM Organization: Education Technology Centre of B.C. Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR Hello, My name is Gale Parchoma and I am a teacher-librarian in British Columbia. a student has asked me to find the fuel capacity for a 747 plane. I do not have that information in my collection. If there is an expert out there who can help, we would both appreciate it. My E-mail address is gparchom@cln.etc.bc.ca Thanks in advance, Gale From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: rfresh@ix.netcom.com (Ralph Freshour) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR In d_gooch@pavo.concordia.ca (GOOCH, DANIEL) writes: > In response to someone who posted a while back regarding if it was >possible to open a door in flight, I just read an article on clari about >a guy who tried to open a door on an American MD-11. The article said that >a numerical code would have been needed to open the door (huh? I assume >this would be ONLY in the air) and that the air pressure at the altitude >the plane was at would have kept the door closed. On the L-1011 TriStar and the B-727, at least, they have "plug type" doors. They must move IN before they can be opened (I assume all jetliner doors work the same way) therefore, there is NO WAY during pressurized flight that you could open a door! The PSID would be too great! If the door had a manual handle (B-727) you *might* be able to unlock it but you could not open it in flight. The L-1011 door is electric. --Ralph Freshour From kls Tue Oct 25 10:24:06 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 25 Oct 94 10:24:06 Status: OR >On the L-1011 TriStar and the B-727, at least, they have "plug type" >doors. They must move IN before they can be opened (I assume all >jetliner doors work the same way) According to various references related to the early DC-10 cargo door problems, all cabin doors on recent Western jetliners are either plug or "semi-plug" design. I'm not sure exactly what the latter is talking about. In any case, the DC-10 cabin doors are indeed plug designs. (Cargo doors are another matter. The L-1011 uses plug cargo doors, but it's the only jet that comes to mind for which this is the case. The DC-10 -- and 747 -- certainly do not have plug cargo doors.) -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Sun Oct 30 21:29:39 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: 747 Fuel Capacity References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:39 Status: OR In article , Gale Parchoma wrote: >My name is Gale Parchoma and I am a teacher-librarian >in British Columbia. a student has asked me to find >the fuel capacity for a 747 plane. I do not have that >information in my collection. If there is an expert >out there who can help, we would both appreciate it. These numbers are for the 747-400: Center tank 17,164 USG Inboard mains 25,092 USG Outboard mains 8,964 USG Reserve tanks 2,644 USG Manifold & line 121 USG __________________________________ Total usable 53,985 USG Stabilizer fuel (option) 3,300 USG Total usable 57,285 USG This is assuming Pratt & Whitney engines. The drybays vary depending on the engine type. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Sun Oct 30 21:29:39 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: psagdeo@aol.com (Psagdeo) Subject: Re: 747 Fuel Capacity References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:39 Status: OR In article , gparchom@cln.etc.bc.ca (Gale Parchoma) writes: The fuel capacity of the airplane varies according to the model and the specifice mission it is flying. Jane's All the World's Aircraft, a yearly publication provides details of this as completely as you can find in open literature. I am sure you will find it in your local public library, if it is comprehensive enough or in the engineering library of the University of British Columbia. If you do not, write back, I should be able to get if for you in a day or so. Hope this helps. Pradip Sagdeo From kls Sun Oct 30 21:29:39 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Don Webster <71352.340@compuserve.com> Subject: Re: 747 Fuel Capacity References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:39 Status: OR >a student has asked me to find the fuel capacity for a 747 plane. I have not been reading this section until now, so this question may have already been answered, but, the capacity of the 747-400 is approximately 57,164 gallons, which includes 3,300 gallons in the horizontal stabilizer. Fuel is contained in six wing tanks,a center wing tank and the stabilizer tank. In the 747-400 the fuel transfer process is scheduled automatically with the pilots being notified by alert messages to turn off certain pumps when a tank is empty. On a flight from San Francisco to Hongkong, we will burn about 55,000 gallons. Hope that helps. Don Webster 71352.340@compuserve.com From kls Sun Oct 30 21:29:39 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: 747 Fuel Capacity References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:39 Status: OR In article , gparchom@cln.etc.bc.ca (Gale Parchoma) wrote: > My name is Gale Parchoma and I am a teacher-librarian > in British Columbia. a student has asked me to find > the fuel capacity for a 747 plane. I do not have that > information in my collection. If there is an expert > out there who can help, we would both appreciate it. The 747-400 has a capacity for about 390,000 lb of fuel. It varies slightly with engine type due to the weight of the engines. Since the JP-4 jet fuel usually used weighs 6.55 lb per gallon, this corresponds to 59,542 gallons. However, with this much fuel the airplane cannot carry full payload, limited by the structurally limited maximum airplane weight. Therefore this much fuel is seldom carried. -- Richard Shevell Email: shevell.leland.stanford.edu From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: mateos@minerva.cis.yale.edu (Matthew J O Scott) Subject: Re: LG wheel hydraulic drive motors References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Yale University Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR Bill Simpson wrote: : I saw a paper that had been given at an SAE A6 meeting on the use of : hydraulic motors to apply torque though gearboxes to landing gear wheels : and thus move the airplane on the ground. This would allow maneuvering : the airplane on the ground with only its APU operating to drive a : hydraulic pump. Have high torque low speed wheel hub or direct drive : motors been considered? These are widely used for off-the-road vehicles, : etc. The motors would have to freewheel or be mechanically disconnected : during takeoff and landing. Very high torque low speed motors would be : required to move a 747 size airplane. The motors would have to be built : to aerospace standards of light weight and high strength. I don't see how or why this idea would fly. (Excuse me) 1. The weight penalty would be exceesive for a feature that has no clear and immediate benefit. (Aircraft have done fine without directly driven wheels for the entire history of aviation. The Wright Brothers of course, had a ground drive system of sorts, but we understand why it was necessary for them) 2. Airlines are interested in fuel savings. Yes, a hydraulic torque pump running on APU juice would consume less fuel than all four fires on a jumbo, but as it is, almost every airline only runs essential engines while taxiing after landing (Jumbos shut down the two outboard ones, commuter twin-turboprops shut down the port engine next to the door) after landing. Most big jets get pushbacks from their gates (unless they are able to taxi straight forward from the gate) that save fuel. Frankfurt Airport at one point in the late eighties (someone help me out, tell me if they still do it) practiced a policy of towing all the widebodies right out to the holding point to save fuel (and cut down incredibly on jet fuel - hundreds of tons a year). I have a hard time seeing how even lightweight, high strength direct-drive motors designed for ground handling would take off (excuse me again). A simple system to spin up landing gear wheels just prior to touchdown might reduce wear and tear on tires, but it is hard to see designers embrace the weight penalty involved across the board. __________________________________________________________________________ Matthew Scott "I'm an Englishman in New York." Sting Yale University "I'm a Canuck in Connecticut, eh!" M.S. From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ehahn@fairlite.mitre.org (Ed Hahn) Subject: Re: LG wheel hydraulic drive motors References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: The MITRE Corporation, McLean, Va. Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR In article news@aol.net writes: I saw a paper that had been given at an SAE A6 meeting on the use of hydraulic motors to apply torque though gearboxes to landing gear wheels and thus move the airplane on the ground. This would allow maneuvering the airplane on the ground with only its APU operating to drive a hydraulic pump. ... The motors would have to freewheel or be mechanically disconnected during takeoff and landing. Thanks Bill Simpson ------ >From an economic standpoint, I'll talk about what the system would have to overcome: 1) Utility: it seems that this kind of system would only work for moving the aircraft forwards, due to the problem of a) seeing what's behind the aircraft, and b) stopping the aircraft while moving backwards. Typically, the only time aircraft move backwards on their own power is during a powerback, where there are people looking out behind the aircraft, and the engines running to stop the reverse motion if it is necessary (hitting the brakes generally would cause the aircraft to rotate back on its tail). If only the APU is running, there wouldn't be a way to stop the reverse motion. Therefore, assuming it can only move the aircraft forward, there must be an incentive to use this kind of system rather than the engines or a tug. Which leads to: 2) Maintenance: because of the moment that the wheel motors will put on the landing gear structure, the maintenance schedule of the landing gear may be impacted, especially as the moment would be typically in the opposite direction of the moment applied by wheel brakes. This in itself might not cost so much. On the other hand, the maintenance of these motors would contribute to added cost to maintain the airframe, compared with the cheaper maintenance cost for tugs and other towing vehicles. Furthermore, unless an entirely independent hydraulic system is included in the aircraft, the motors will be hooked into the main hydraulic system, which means the motors must be designed to minimize impact on the flight control system in case of a leak, etc. To size the added maintenance cost, flight delay/cancellation roughly impacts airline operations anywhere from about $2500 for a short delay to $75,000 for a cancellation, depending on aircraft size. 3) Weight: each extra pound an airliner must carry for an entire year roughly costs $1000/year. Is the utility gained by the addition of a wheel motor system going to offset this additional cost? 4) Safety: if the above mentioned freewheeling or torque disconnect failed on a landing, how would this affect the aircraft? Anyways, these are my thoughts on the wheel motor system. Any inaccuracies in the concepts or numbers are mine only. ed //////// Ed Hahn | ehahn@mitre.org | (703) 883-5988 \\\\\\\\ The above comment reflects the opinions of the author, and does not constitute endorsement or implied warranty by the MITRE Corporation. Really, I wouldn't kid you about a thing like this. From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR In article , Karl Swartz wrote: >(Cargo doors are another matter. The L-1011 uses plug cargo doors, >but it's the only jet that comes to mind for which this is the case. >The DC-10 -- and 747 -- certainly do not have plug cargo doors.) The 737 in all its myriad forms uses plug type cargo doors. Interestingly, they actually cause less lost volume than the outward opening doors of the competing A320. -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: johncook@nr.infi.net (John Cook) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: InfiNet Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR The number code on the door must have been on a Lincoln! Even if you did move the handle on the 727, it would only serve to turn on a door open warning light on the FE's panel. The 8.4 plus PSI within the cabin would preclude any problems with somebody other than Arnold S. opeing one. In fact, the limitations for opening must be .5 PSI or less. Even a little bit of pressure trapped inside causes a problem. From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: wpcallah@rwasic17.aud.alcatel.com (Paul Callahan) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR >According to various references related to the early DC-10 cargo door >problems, all cabin doors on recent Western jetliners are either plug >or "semi-plug" design. I saw a PBS (Nova ??) on a "new" design, I think the 777. Where the door did not have to move into the cab. to open. They spent some time on the show, showing a test to verify that the door could open under icy and cold conditions. They said that there was much customer interest in "easy" to open doors, which did not have to move inside first. This was memorable, because I thought the inherent safty of the plug design, would keep it for a long time.... >(Cargo doors are another matter. The L-1011 uses plug cargo doors, >but it's the only jet that comes to mind for which this is the case. >The DC-10 -- and 747 -- certainly do not have plug cargo doors.) > Why not plugs here? Again, it's easy to argue that they have better safty, as in the DC-10 reference. Does anyone know if this is due to ease, cost, or the fact that more cargo can be pput next to the door, if you don't have to leave space to move the door into the cargo area, and then rotate it? Paul Callahan From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: mdrews@iguana.dsd.es.com (Michael Drews) Subject: Re: Glass Cockpits' Video Rates? References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: mdrews@iguana.dsd.es.com (Michael Drews) Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR In article , "Reply to: philip_decker@lds.loral.com" writes: > Am curious about the characteristics of the video signals displayed in > glass cockpit aircraft: sync frequencies, resolution, (non)interlace, > etc... Also, are all the displays (vertically) sync'd to each other? > As far as I know all glass cockpit displays are caligraphic, not raster. Caligraphic displays offer much higher contrast and brightness. Refresh frequencies can be increased to increase brightness. (Caligraphic displays draw the lines and curves Etch-A-Sketch style.) Disclaimer: I have not had a peek in any of the more modern glass cockpits. This is from 757 and 767 observations. Michael Drews -- ----------- "These aren't the droids you're looking for." From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: sr001b@uhura.cc.rochester.edu (Still Searching . . .) Subject: Shuttle aircraft Message-ID: Approved: kls@ohare.Chicago.COM Organization: University of Rochester - Rochester, New York Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR About 2 weeks ago, I flew ROC -> BOS via LGA. I flew the USAir Shuttle from LGA-BOS. The inside of the seemed to be nice many years ago when it must have been new but the years have taken their toll. Why is this aircraft still the most popular on this route? Why not switch to a more economical Fokker 100 or soemthing during off-peak hours? --Satya sr001b@uhura.cc.rochester.edu From kls Sun Oct 30 21:29:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: petercoe@netcom.com (Peter J. Coe) Subject: Re: surprise engine order References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NETCOM On-line Communication Services (408 261-4700 guest) Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:40 Status: OR Andrew Chuang writes: >It's reported in >Financial Times that SIA is going to order Rolls-Royce Trent for the >B777. What did BRitish Airways end up ordering for the 777, was it the GE engine? Has anyone got easily to hand an approximate breakdown of the B777 orders? From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lmnp1@eng.cam.ac.uk Subject: Re: Martin Marietta's APALS Message-ID: Approved: kls@ohare.Chicago.COM Organization: Cambridge University Engineering Department, UK Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR According to 5-11 October 1994 issue of Flight International, Martin Marietta is attempting to market a new approach and landing aid designed to chnage the approaches are made. The system is called APALS (Autonomous Precision Approach and Landing System). The way it works is it enhances the aircraft's existing weather radar to produce ground images of sufficient resolution to allow matching with a terrain database. The correlation of actual radar image and the database scene produces an error which is used to update the aircraft's Inertial Navigation System (INS). The new position is used to predict what the next radar image will be, and so on. APALS does not require ground aids such as ILS or airport lighting but does require an airborne global-positioning-system (GPS) and the creation of a terrain database for all approaches to be flown. Full benefits of the system can be realised if used with a head-up-display (HUD) which recreates an image of the approaching runway including touchdown markers. I would like to point out the advantages and disadvantages of this system. Firstly the fact that it does not require any ground aids means that you can land your aircraft on any airport in case of emergency provided the system database has the image data. This system is ideal for airports like Katmandu in Nepal where there are limited ground aids and poor visibility. This system could be another solution to the replacement of ILS in Europe where the VHF band will reach saturation by 1997. However the idea if being totally independent of ground aids can be dangerous in the case of system malfunction. Due to its reliance on GPS the accuracy cannot be guranteed unless high acurracy high cost GPS recievers are used. The database should cover all of the main airports throughout the world if it is to be used internationally and the terrain data should be constantly updated since features such as roads, building edges are used for correlation. All of this means that the operating cost of APALS could be very high and higher than operating the existing ground based approach and landing systems. Any comments are welcome. It should be noted that this article is intended to point out the advantages and disadvantages of using APALS and not to criticise Martin Marietta's products. From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rkeen@sunfish (robert keen) Subject: Q: Banking angles of airliners? Message-ID: Approved: kls@ohare.Chicago.COM Organization: Harris Electronic Systems Sector Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR What are "typical" banking angles (roll) of commercial airliners? Please mail to me at rkeen@sunfish.ess.harris.com thanks for any help. Mike Keen From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hrz090@aixrs2.hrz.uni-essen.de (Dr. Erdelen) Subject: "Die Zeit" article on Airbus (longish excerpts) Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR Hello, airlinerers & airlineresses, in its issue 43 (21 Oct. 1994), "Die Zeit", a major German weekly, carries an article on the Airbus crashes of recent times. Here's an excerpt. See end of message for motivation and comment. [Stuff in brackets is mine. Sorry for probable partial unidiomacy.] The accidents at the base of the report will be well known to readers of "airliners" (A300 at Nagoya, Japan, in April; A330 test flight near Toulouse in June; A300 near-crash at Cheju Island, Korea; Tarom A310 near-crash; Mulhouse 1988 airshow A320 crash; Bangalore 1992 A320 crash; Strasbourg 1992 A320 crash). More interesting is that the article does not describe glass cockpit / fly-by-wire as inherently dangerous, but rather emphasizes problems of human perception of and reaction to computerization, as well as insufficient training procedures: "All pilots had blindly trusted their machines." Lufthansa Check Captain Georg Keil is quoted as stating that the cause of the accidents is not the computer system but rather the attitude towards technics in general: "It starts with the question if one should sell planes as fool proof systems, or as systems which require diligent operation." The (wo)man/machine interface is seen at the base of the errors. Keil: "This is the fatal consequence of the misconception that one can reduce training." The report states that Lufthansa trains its pilots in-house, and not at Airbus in Toulouse: "At Toulouse, it is said, there are trainers who have never flown an airliner with actual passengers, whereas at Lufthansa, experienced line captains handle the training. They know all problems which occur in line operations, and also the practical consequences of design errors in newly introduced airliner types. Flight trainers without line experience know these only in theory." Lufthansa is further reported to emphasize human factors during training. Blind trust in technics is discouraged. "Instead, the so-called crew resource management (CRM) centers on stress-free communication between captain, co-pilot, and computer." Airbus is said to have by now recognized that "pilot training has to be adapted to the participants' needs, and not vice versa. They, too, now offer a seminar on communication and teamwork in the cockpit." The article goes on to quote Christian Kepp, Lufthansa captain since 27 years, member of the Workgroup "Accident Analysis" of Cockpit [union style association of German airline pilots]. He summarized his experiences with the Airbus in a paper sent to the Luftfahrtbundesamt [Federal Aviation Office; German equivalent of the FAA], and expresses severe critique. Quote from that paper: "If something goes wrong, it is [allegedly] always the pilot's fault if the technics he has to handle turns out to have worked as defined. [However,] The question how good or bad the technics has been adapted to his needs, and if he could at all have influenced it in the situation, is then not even asked." Cockpit demands a partial reversal of [backstep from] computer use from Airbus: "No system indispensable for flight operation (such as engine or brake control) must be controlled by automatics which the pilot cannot influence." Kepp also criticizes the glass cockpit: "Man-machine communication mainly uses the optical channel, hardly the acoustical, and not at all the tactile (after the introduction of the side-stick). [...] In complex situations, the optical channel breaks down incredibly early." The article mentions that the Boeing 777 will have a glass cockpit and fly-by-wire, but will revert to a traditional style "stick" (yoke) with computer-generated "feel of resistance". (It also says that even in pre-computer times, "stick resistance" was not real but rather simulated by the hydraulic system.) The "Zeit" report is complemented by an interview with Bernard Ziegler, Vice President [??, or some such; I'm unfamiliar with business ranks] of Technics at Airbus Industries. Ziegler denies that design errors have been involved in the crashes, and says that the problems between computer and human are "not specific for the computer, but a problem of the pilot who has to understand how a plane flies. We are not born to fly as birds are. There is a huge difference between the instinct of man and of birds. Therefore, there will always be misunderstandings between man and the flying machine. Three crashes during approach (two at Katmandu, and one at Strasbourg, with different Airbus types) basically had the same reason, among others that man has no inborne instinct for height, for distance from ground. "Q: Do you have to revise your concept of taking work load off the pilot and give more responsibility to the computer? " Ziegler: No, no, no. It is the responsibility of all aircraft manufacturers to deal with human errors and to build into the planes technical devices which prevent that those errors llead to catastrophes. For errors are in the human nature. We cannot prevent pilot errors, but we have to prevent that they lead to catastrophes. This is and remains our philospophy. "Q: Does this not mean that humans are to be banned completely from the cockpit? "Ziegler: No, definitely not! The human is the only one who can react quickly to the unexepcted, the un-programmable. [e.g. pilot has to decide on aborting a fully automated landing in extremely poor visibility]. [Q: on Boeing 777 reverting to traditional type yoke, see above] "Ziegler: With this, Boeing has overdone [exaggerated] technics. They introduce another automatism which is not necessary. This is pure cosmetics. We will never introduce a technique which is not necessary." [end of summary/excerpt] [The above is an excerpt/summary, *not* my opinion (as if I had one on religious subjects like Airbus...). I started to summarize the Zeit article because I felt it might indicate that some re-orientation, much advocated also by members of this list, has finally trickled through to the industry: namely that the strategy of exposing "pilot's error" at the base of all accidents, even if that were true, is not a satisfactory state to leave things in. On second reading, esp. of Ziegler's statements, I'm not so sure about the re-thinking done. Maybe Lufthansa got the message, but as to Airbus, I'll leave the conclusion to the readers. If anyone wants the complete article (in German, of course), e-mail me privately.] MArtin Erdelen From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Nicolas Ercan Murat Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR > I'd like to know the validity of the reports on the failure of the > 777 P&W engine while being certified for ETOPS. Can anyone shed > any light on this? This supposedly occured sometime last week. It sure seems that P&W have been having some bad luck with their new engines. After the A330 crash while testing the new Pratt, here comes a failure while testing the one for the Triple 7.... Can't be too many happy people at P&W these days... Bernie. From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lmnp1@eng.cam.ac.uk Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Cambridge University Engineering Department, UK Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR A recent issue of Flight International had an article on delays in the ETOPS certification programme although it was commenting on the delays to the 1000 cycle test on a Boeing 777. From kls Sun Oct 30 21:29:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: gclst1+@pitt.edu (Grant C Lynde) Subject: Quiet ride Message-ID: Approved: kls@ohare.Chicago.COM Organization: University of Pittsburgh Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:41 Status: OR This past weekend, I flew on an MD-80 and on an F-100. It's been over a year since I had been on either plane, but was surprised as to how quiet they seemed. Is it my imagination that they aren't as noisy as they were a few years ago, or have they (whoever they may be) been doing something about the cabin noise caused by the engines??? Grant Lynde From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: saghir@eecg.toronto.edu (Mazen Saghir) Subject: Reverse Thrust on a 757 Message-ID: Approved: kls@ohare.Chicago.COM Organization: Department of Computer Engineering, University of Toronto Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR While waiting for our flight to take off at DFW, I noticed that two 757s landed and had reverse thrust applied before their front landing gears had touched the ground. Is this standard procedure? I though that reverse thrust is applied after all wheels are on the ground. From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: V.A.LEWIS@dundee.ac.uk (VAUGHN LEWIS) Subject: Project 777 Message-ID: Approved: kls@ohare.Chicago.COM Organization: University of Dundee Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR Hello out there. I'm am performing a case study in project administration and would like to get some details from Boeing or anynoe out there on the project to create the Boeing 777. Some of the details that I am looking for are the origins of the project; the participants in the project; the project deadlines; and if possible the people or companies responsible for different aircraft systems such as the engines, avionics etc. If anyone does send any information please post to : valewis@its.dundee.ac.uk Any help will be greatly appreciated. Thanks in advance. Vaughn Lewis From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hrz090@aixrs2.hrz.uni-essen.de (Dr. Erdelen) Subject: Cruise Altitude Schedules Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR Hi, flyers, speaking of cruise speed and altitude schedules: I have often wondered what the flight level pattern might be on short flights covering a distance of, say, 400 to 500 km (216 to 270 nm). Many domestic flights in many European countries fall into this category. Is it at all economic to use jets (such as 737) for these? I seem to remember that somebody on this list (rdd?) once mentioned nearly parabolical altitude trajectories, but I can't find the exact quote. Would someone care to elaborate? Over here, there are people - of the ecological mindset - who demand a ban on all flights covering less than 500 or 400 km, on the grounds that railways would make much more sense for these distances - ecologically *and* economically. Would reasons of purely technical economy - apart from marketing strategies and such - tend to support that demand? Are "short hops" inordinately expensive? Thanks in advance for all comments. With best regards, MArtin From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Cruise Altitude Schedules References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR >Hi, flyers, There's a *really* bad pun there for an article about altitudes! :-) >I seem to remember that somebody on this list (rdd?) once mentioned >nearly parabolical altitude trajectories, but I can't find the exact >quote. I don't recall the quote either, but I've been on flights from San Francisco to Los Angeles (337 miles) that had a cruise altitude of 39,000 ft. These were all on lightly loaded 757s, which have incredible climb performance. Even at that, we only spend a few minutes at "cruise" altitude. I never thought about it in such terms, but the profile probably was close to parabolic. In contrast, I've flown between Los Angeles and San Diego (109 miles) a few times on 737s, and once on a 757. The 737s leveled off at either 10,000 or 12,000 ft, I can't recall which. I'm not sure about the 757 but I'd imagine it was about the same. >Would reasons of purely technical economy - apart from marketing >strategies and such - tend to support that demand? Are "short hops" >inordinately expensive? For a given aircraft type, there are a lot of fixed costs, with rather small marginal costs for additional distance. Gate and other ground costs associated with cramming 126 people on a 737-300 and then getting them off at the other end don't much care whether you're going 100 miles or 1,000 miles. Same for landing fees, maintenance and airframe life costs as a result of an additional takeoff/landing cycle, etc. It doesn't require all that much more fuel to get to cruise if you're going to stay there for an hour than if you're just there for a few minutes. Looking at it another way, that SFO-LAX flight was schedule for about 90 minutes. Add in another 60 minutes at the gate before each flight (assuming we aren't talking about Southwest-style turnarounds). So let's say you've paid for crew, airplane, etc. for 2.5 hours, all for less than 10 minutes of cruise. Doubling the mileage will probably require about 45 minutes more at cruise, a 100% increase in distance for a 30% increase in time (and associated costs) with somewhat more fuel and essentially the same fixed costs. On the other hand, short-range planes are designed for the job, and have design compromises that presumably reduce the cycle-related costs. A 737, for example, isn't capable of the cruise altitudes a 757 or 767 can reach, because the extra weight required wouldn't be worth the cost given how little time a 737 would spend at those altitudes. At the other end of the spectrum, flying a 747 on 500 mile segments will rather rapidly use up the structural life of some key components, such as landing gear. (This is why JAL and ANA have special domestic 747 variants, which are beefed up in the key areas.) -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Stephen L Nicoud Subject: Re: Accident/incident data References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR From: ditka!sgiblab!uunet.uu.net!SSD-HB!gershzohn.gary (B&1&2) (fly boys) Can anyone tell me where I can find data on recent aircarft incidents and accidents in which human factors was cited as a contributory cause. For example, I am interested in statistical summaries that identify the percentage of accidents and incidents atrtributed to "pilot error". Reports; books; contacts at Boeing or Airbus; and contacts at the FAA or NTSB would be highly appreciated. What you want can be found in this 41 page report: "Statistical Summary of Commercial Jet Aircraft Accidents, Worldwide Operations, 1959-1993" March 1994 This report is published annually by: Airplane Safety Engineering (B-210B) Boeing Commercial Airplane Group P O Box 24346 MS 9U-MA Seattle WA 98124-0346 USA Requests for the report should be sent to that address. Stephen -- Stephen L Nicoud bcstec!bcsaic!stephen.nicoud This message does not represent the views of The Boeing Company. I am not a spokesperson for The Boeing Company. All rights reserved. From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ldorr@admingw.hq.nasa.gov (Les Dorr, Jr.) Subject: Re: Accident/incident data References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NASA HQ Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR In article , ditka!sgiblab!uunet.uu.net!SSD-HB!gershzohn.gary (B&1&2) (fly boys) wrote: > Can anyone tell me where I can find data on recent aircarft incidents and > accidents in which human factors was cited as a contributory cause. For > example, I am interested in statistical summaries that identify the > percentage of accidents and incidents atrtributed to "pilot error". > Reports; books; contacts at Boeing or Airbus; and contacts at the FAA or > NTSB would be highly appreciated. For incident info, contact the Aviation Safety Reporting System at NASA's Ames Research Center in Mountain View, Calif. Largest aviation human factors database in the world. Ames' Main # is 415/604-5000. Ask for Bill Reynard. -- Les Dorr, Jr. NASA HQ "Suppose you had everything in the world--where would you put it?" --Steven Wright From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lambrose@csc.com (Laren Ambrose) Subject: Re: Accident/incident data References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Computer Sciences Corporation Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR : Can anyone tell me where I can find data on recent aircarft incidents and : accidents in which human factors was cited as a contributory cause. For : example, I am interested in statistical summaries that identify the : percentage of accidents and incidents atrtributed to "pilot error". : Reports; books; contacts at Boeing or Airbus; and contacts at the FAA or : NTSB would be highly appreciated. I will see what I can do about an FAA contact. This may take me a bit of time. I am on contract to work on the Airports Division business computers, and the Airports Division only gets involved in an investigation if there may be a problem with runway lights, signs. I will pass on your request to other Divisions and pass back any response I get. You might try calling the local FSDO and asking for the information under the Freedom of Infomation Act. Laren Ambrose Computer Sciences Corp. Contract to the: FAA Airports Division, Seattle (206) 227 2956 (or) lambrose@connected.com (or) lambrose@hq.faa.gov ** My comments are from me, not the FAA or CSC ** From kls Sun Oct 30 21:29:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: george0326@aol.com (George0326) Subject: Re: Accident/incident data References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 30 Oct 94 21:29:42 Status: OR Crew error is typically stated as a cause of about two thirds of aviation accidents. This includes failure to properly respond to an in flight mechanical or electrical problem. Good sources of mishap summaries include the International Society of Aviation Safety Investigators, the FAA, NTSB, and the service's respective Safety Centers. The US Army Safety Center has compiled a comprehensive evaluation of helicopter crew error mishaps, of all phases of flight from pre-flight to tie-down, including crew coordination, workload, etc. From kls Mon Oct 31 01:58:18 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hess@boi.hp.com (Kevin C. Hess) Subject: Re: Wanted: Info on Airbus References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Hewlett Packard Sender: kls@ohare.Chicago.COM Date: 31 Oct 94 01:58:18 Status: OR ABC's request for more information on Airbus Pilot/systems interface issues should be considerd in context *PRIOR* to responding to their request. As an owner of firearms, I have had the chance to observe the medias' approach when dealing with substantive issues which they do not understand. The approach used is to collect pertinent technical and statistical data, as well as meaningfull opinions from those "in the know". The information that is collected by the "research" reporter is then passed on to at least one, but sometimes more than one, staff writer. The writer(s) generally try to make a balanced story, but have received the material second hand and usually fail to understand the deeper technical issues that are directly associated with the topic being discussed. This is a direct result of the writers not being present during any interviews being conducted, and therefore unable to ask followup questions for clarification. After the story is written, it is usually passed through the review of both and editor, and the producer of the show/news. These folks have little concern for accuracy, rather their concern is to ensure that the show is "watchable" (read as sensational) and "isn't too deep for the common man" (read as oversimplified). Note: there is no concern for the truth. The net result of such efforts on your part to explain in depth the issues at hand is the garbling of the story (from your point of view). Quotes you have made will be taken out of context. Explanations which make the subtle points clear are totally lost. The effort you have expended in helping them build a story is not the story you thought it would be. As an exercise, if you do choose to contact ABC and offer assistance, ask them for the right to review the story prior to broadcast, and if you find it unacceptable, to pull your contribution. THe response you get to this request can be used as a guage for the honesty and flexability of the organization you are dealing with. I started by saying that I own firearms, and through that my exposure to the press has been shaped. Without considering your personal stand on the issue of private ownership of firearms, ask yourself this question: Have I seen as many positive stories on firearms as negative ones? If not, then you might think about the result of your efforts if you replace "firearm" with "Airbus" or even the generic "airplane". Do you wish to have a reporter, editor or producer do a hatchet job on a device you are associated with, simply because it suits thier needs? -Kevin The statements/opinions expressed here are not necessarily those of the Hewlett-Packard Company. HP paid a research firm millions of dollars to get their own opinions, and has made it clear they do not wish to share mine. Kevin C. Hess (KB7UKR) Hewlett-Packard Network Printer Division hess@hpdmd48.boi.hp.com (208) 396-3384 Boise, Idaho 83704 From kls Tue Nov 1 00:06:52 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: chuanga@iia.org (Andrew Chuang) Subject: Re: surprise engine order References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: International Internet Association. Sender: kls@ohare.Chicago.COM Date: 01 Nov 94 00:06:52 Status: OR Just a clarification of my previous posting, Singapore's order is not official, yet. In article , Peter J. Coe wrote: > >What did BRitish Airways end up ordering for the 777, was it the GE engine? yes > >Has anyone got easily to hand an approximate breakdown of the B777 orders? > Airline Firm Option United 34 34 All Nippon 15 10 Japan 10 10 Japan Air System 7 0 P&W total 66 54 BA 15 15 EuralAir 2 0 Lauda 4 0 ILFC 6 2 China Southern 6 0 Continental 5 5 Gulf Air 6 6 GE total 44 28 Thai Int'l 8 0 Emirates 7 7 Cathay 11 0* (*options on 11 a/c cancelled after the A340 order) Transbrazil 3 0 R-R total 29 7 Korean Air 8 8 Undecided total 8 8 Potential new customers which have been mentioned in the news Saudia Singapore Virgin Atlantic Air-India (I just saw an Airbus A340 printed ad touting A340's capability to fly non-stop between DC and Delhi) -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Tue Nov 1 00:06:53 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: Opening a door in flight References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 01 Nov 94 00:06:53 Status: OR In article , Paul Callahan wrote: > >They said that there was much customer interest in "easy" >to open doors, which did not have to move inside first. >This was memorable, because I thought the inherent safty >of the plug design, would keep it for a long time.... The 777 cabin doors are plug type doors. That is, the structure of the door is wider than the opening in the door frame structure. >>(Cargo doors are another matter. The L-1011 uses plug cargo doors, >>but it's the only jet that comes to mind for which this is the case. >>The DC-10 -- and 747 -- certainly do not have plug cargo doors.) >> > >Why not plugs here? Again, it's easy to argue that they >have better safty, as in the DC-10 reference. Does anyone >know if this is due to ease, cost, or the fact that more >cargo can be pput next to the door, if you don't have to >leave space to move the door into the cargo area, and then >rotate it? Lost cargo volume for the twin-aisle airplanes is economically significant if the main cargo doors open inward as a plug door does. That is one lost container or pallet position, per door, or roughly 10% of your available revenue cargo volume. This is because the doors are large enough to accomodate containers and pallets, unlike most single-aisle airplanes (the A320 is the only exception that comes to mind). The smaller bulk doors don't have this problem, and can generally be kept as plug doors, though there is some marketing pressure to turn them into outward opening doors to gain that last couple of cubic feet of volume. The 757, for example, has outward opening cargo doors, but is loaded bulk only. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Tue Nov 1 00:06:53 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rogerc@dev1.ssd.fsi.com Subject: Re: Glass Cockpits' Video Rates? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: FlightSafety Simulation Systems Division - Tulsa Sender: kls@ohare.Chicago.COM Date: 01 Nov 94 00:06:53 Status: OR > In article , > philip_decker@lds.loral.com writes: > > Am curious about the characteristics of the video signals displayed in > > glass cockpit aircraft: sync frequencies, resolution, (non)interlace, > > etc... Also, are all the displays (vertically) sync'd to each other? > > > As far as I know all glass cockpit displays are caligraphic, not raster. > Caligraphic displays offer much higher contrast and brightness. Refresh > frequencies can be increased to increase brightness. > > (Caligraphic displays draw the lines and curves Etch-A-Sketch style.) > > Disclaimer: I have not had a peek in any of the more modern glass > cockpits. This is from 757 and 767 observations. > > Michael Drews I'm not familiar with the details of how the new flat panel displays are driven as in the new Boeing 777 aircraft, but the typical EFIS display used throughout the industry receives raster video and stroke (vector) video. It is true the stroke video handles a major portion of the graphics such as text, lines, and symbols. Raster display however is still required or at least is used to quickly fill large areas of the display such as the sky/ground background and weather radar video. EFIS tubes which provide for both raster and stroke display apparently don't come cheap either. For simulation purposes, the EFIS displays will usually be pure raster graphics (much cheaper) and the resolution is quite nice. Hope this explains a little more. - - - - - - - - - - - - - - - - - - - | Roger Chandler | | Senior Engineer - Navigation/Visual| | FlightSafety International - | | Simulation Systems Division | | Ph: 918-251-0500 Fax:918-251-5597 | - - - - - - - - - - - - - - - - - - - From kls Tue Nov 1 00:06:53 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Jim Hogan Subject: Rain in the plane Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 01 Nov 94 00:06:53 Status: OR I am investigating measures to prevent or manage the problems associated with the excessive condensation of water vapor on cold airplane skin and structure (interior) during long, high occupancy flights. Active dehumidification of the cabin air is not a desirable solution due to the operational drawbacks of the equipment and the risks associated with excessively drying the air (comfort and static problems). Any novel ideas regarding this topic would be appreciated. Thanks! Jim Hogan jimh@eskimo.com From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rna@leland.Stanford.EDU (RNA) Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: rna@gsb-ecu.stanford.edu Organization: Stanford University, CA 94305, USA Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR In article , Nicolas Ercan Murat wrote: >> I'd like to know the validity of the reports on the failure of the >> 777 P&W engine while being certified for ETOPS. Can anyone shed >> any light on this? This supposedly occured sometime last week. > >It sure seems that P&W have been having some bad luck with their new >engines. > >After the A330 crash while testing the new Pratt, here comes a failure >while testing the one for the Triple 7.... > >Can't be too many happy people at P&W these days... Nor at GE, I have read that they too are having setbacks with the GE90 certification. Something to do with the new wide-chord fans in the engine. Can someone in the know please elaborate? RNA From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rsolene@aol.com (RSolene) Subject: Boeing 777 Wing Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR When the 777 project was first announced some four years ago, I recall wing specs that called for winglets in addition to folding wing tips. I know the winglets have since not been incorporated, at least in the prototype, but what about the folding wings? I understand that it was supposed to be an option. Have any airlines ordered the plane with the folding wing option? Also, how does the 777 compare performance wise with its competitors, the A340 and MD-11? Did Boeing use the late start to its advantage by capitalizing on the 777's competitor's shortcomings (after observing feedback from customers of the other aircrafts)? R. Solene From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Boeing 777 Wing References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR >... what about the folding wings? I understand that it was supposed >to be an option. Airliners were more worried about the weight and complexity than they were about fitting the 777 into gates, so Boeing offered them the option of installing the hinges and such but not the mechanisms to actuate the whole thing. This produced a 1,900 or 2,000 lb savings, and nothing to go weird in flight, while preserving the option of installing the folding mechanism later if desired. United, the 777 launch customer, still wasn't happy about the weight, as they wanted non-stop Chicago to Hawaii range. Their initial order specified an increased MGTOW of 525,000 lbs (vs. 505,000), and fixed wingtips without even the hinges or provisions for folding, a savings of 3,900 lbs over the folding design. Boeing relented after devising a way to build both variants without dramatic tooling changes. >Have any airlines ordered the plane with the folding wing option? No, though as far as I know it's still an available option. I think Boeing was planning on putting folding wings on one of the aircraft for certification purposes, though as far as I know all of the orders are for permanently fixed wings. >Also, how does the 777 compare performance wise with its competitors, the >A340 and MD-11? Did Boeing use the late start to its advantage by >capitalizing on the 777's competitor's shortcomings (after observing >feedback from customers of the other aircrafts)? >From what I've heard, the 777 has met or exceeded its fuel consumtion and performance goals from day one, in contrast to the well-publicized problems with the MD-11. I don't really know how the A340 did, but shortfalls are fairly common. In a more general sense, Boeing certainly capitalized on their late entry in one very big way -- newer engine technology, which through higher thrust permitted Boeing to offer an aircraft in the same general range and payload class as the A340 and MD-11, with the economic benefit of having only two engines. There is a catch in this, though, since you either have to get ETOPS right away or not need ETOPS. While United originally needed 180-minute ETOPS for the Hawaiian routes, it would not have hurt too much to keep them on 48-state/Canada/Alaska routes at first. Now that United has switched the first batch from domestic to international aircraft, they can manage with 90-minute ETOPS for trans-Atlantic flights (or no ETOPS for South America) but United's experience with ETOPS makes it a fair bet that they'll have ETOPS from day one. In contrast, Virgin Atlantic chose the A340 over the 777 in part because the 777 would need ETOPS, which Virgin, with no ETOPS track record, would find hard to obtain. Except possibly for London to Hong Kong the 777 without ETOPS would have been useless. (Airbus was also able to offer a good deal on four aircraft with only a few months lead time due to Northwest's late cancellations.) -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: (Winyard) Subject: Re: LG wheel hydraulic drive motors References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NSWC Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR In article mateos@minerva.cis.yale.edu (Matthew J O Scott) writes: >Bill Simpson wrote: >: I saw a paper that had been given at an SAE A6 meeting on the use of >: hydraulic motors to apply torque though gearboxes to landing gear wheels >: and thus move the airplane on the ground. ... >I don't see how or why this idea would fly. (Excuse me) >1. The weight penalty would be exceesive ... >2. Airlines are interested in fuel savings. Yes, a hydraulic torque pump >running on APU juice would consume less fuel than all four fires on a jumbo, >but ... Let's have some numbers! 1. Assuming a 747, what is the fuel consumption of the normal number of main engines running while taxiing between the gate and the end of runway, including some allowance for waiting in line? 2. How much on landing between the runway and gate? 3. How much thrust is necessary to move a 747 at taxi speeds? 4. What's the incremental SFC for a 747 APU? With answers to these questions the fuel weight/cost penalties of current practices can be brought to light. ADDING a hydraulic motor might SAVE weight! Or maybe an electric motor would be better. David Winyard Annapolis, MD From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hoyme@src.honeywell.com (Ken Hoyme) Subject: Re: Glass Cockpits' Video Rates? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Honeywell Technology Center, Minneapolis, Minnesota, USA Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR In article rogerc@dev1.ssd.fsi.com writes: >> In article , >> philip_decker@lds.loral.com writes: >>> Am curious about the characteristics of the video signals displayed in >>> glass cockpit aircraft: sync frequencies, resolution, (non)interlace, >>> etc... Also, are all the displays (vertically) sync'd to each other? > I'm not familiar with the details of how the new flat panel displays > are driven as in the new Boeing 777 aircraft, but the typical EFIS > display used throughout the industry receives raster video and stroke > (vector) video. Well, the LCD devices on the 777 are inherently raster at the point the pixels are driven. In this case, the issue of stroke and raster treatment of differing data types is an issue for earlier stages of the graphics generation process. The B777 flat panels are updated at a 60Hz rate. I believe that they are vertically synced to each other, but that is not a detail that I have personally worked on. (The architecture is certainly capable of this.) I am not certain that the resolution of these devices has been talked about in the open literature, so I do not feel free to discuss it. Suffice it to say that it is a much finer dot pitch than you see on the average laptop or workstation display. Ken Ken Hoyme Honeywell Technology Center (612)951-7354 3660 Technology Dr., Minneapolis, MN 55418 Internet: hoyme@src.honeywell.com From kls Wed Nov 9 00:51:22 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: rna@leland.Stanford.EDU (RNA) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: rec.travel.air Reply-To: rna@gsb-ecu.stanford.edu Organization: Stanford University, CA 94305, USA Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:22 Status: OR [followup drifts into rec.travel.air territory. Cross posted to r.t.a. with followups to that forum too] The USAir 727s are special I think. USAir Shuttle is set apart from the rest of USAir. It used to be the Trump (Yech!) Shuttle, and there was some agreement under which USAir operates the shuttle for Trump, after the Donald got into financial hot-water. USAir has an option on the Shuttle ownership---I don't know if that option has been exercised. USAir recently made the decision to get rid of the other non-Shuttle 727s in the fleet (I think there are less than ten left). But I don't think there are any plans to upgrade the USAir Shuttle 727s. I wonder if USAir can even afford to exercise the ownership option at the moment, considering it is so close to bankruptcy. In fact such a bankruptcy might lead to yet another change in ownership, depending on the state of the USAir/Trump agreements. Meanwhile the 727 shuttles get nastier and nastier inside. Must be two of the least bang-for-the bucks routes in America. RNA In article , Still Searching . . . wrote: >About 2 weeks ago, I flew ROC -> BOS via LGA. I flew the USAir Shuttle from >LGA-BOS. The inside of the seemed to be nice many years ago when it must >have been new but the years have taken their toll. Why is this aircraft >still the most popular on this route? Why not switch to a more economical >Fokker 100 or soemthing during off-peak hours? > >--Satya >sr001b@uhura.cc.rochester.edu > From kls Wed Nov 9 00:51:23 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:23 Status: OR In article , Still Searching . . . wrote: >About 2 weeks ago, I flew ROC -> BOS via LGA. I flew the USAir Shuttle from >LGA-BOS. The inside of the seemed to be nice many years ago when it must >have been new but the years have taken their toll. Why is this aircraft >still the most popular on this route? Why not switch to a more economical >Fokker 100 or soemthing during off-peak hours? Never having had the pleasure of flying that route, I don't know what airplane is being used. That makes it just slightly more difficult to comment knowledgeably on your question. Would you be kind enough to elaborate a bit? And include the airplane type? Since having full control of the facts has never kept me from commenting on the industry in general or in particular, I thought I'd toss out a couple of possibilities. First of all, most Fokker 100s will have to be purchased new at about $22 Million (US). A very nice 737-200 Advanced or 727-200 Advanced can be gotten for less than a quarter of that, maybe only ten percent (depending on gobs of variable like certified gross weight, avionics, engine type and time, maintenance condition, etc). That $16 Million saved can by a *lot* of fuel and maintenance. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Wed Nov 9 00:51:23 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:23 Status: OR >Never having had the pleasure of flying that route, I don't know what >airplane is being used. Both the USAir (ex-Trump, ex-Eastern) and Delta (ex-Pan Am) Shuttles exclusively use Boeing 727s. Delta's are all -200 Advanced models, while USAir uses mostly original -200s, with several of the Advanced -200s and a few -100s thrown in. The key point here is that these operations are what some would call a "true" shuttle, that is, you're guaranteed a seat even if they have to roll out another aircraft. This is in contrast to United's LA-SF Shuttle service, started a few years ago (not their new Shuttle by United Southwest wanna-be), which was nothing different from the usual fixed-capacity operation other than exceptionaly high frequencies. The guaranteed seat shuttle means you have to have an extra aircraft, crewed, fueled, and ready to go, at each station. The cost of doing this is prohibitive if it means a lot of capital (several expensive aircraft) is sitting around idle. 727s are now old enough to be fully depreciated, and the higher pilot and engine count increase operating costs enough to make them unattractive for shorter flights when 737s and DC-9s/MD-80s are in ready supply. Thus the 727s are attractive for operations, such as the shuttles, in which their utilization may not be very high. (Until recently, United similarly used some of their oldest 727-200s in intra-European routes, where they'd fly one LHR-XXX or CDG-XXX and back trip a day, for various values of XXX.) As one might expect given the circumstances, shuttles have a long history of depending on fully-depreciated aircraft. From inception in 1961, the Eastern Shuttle depended on Constellations, which were well past their prime. Later, Eastern's Electras lasted into 1977 in Shuttle service. Electras also figure prominently in the very first shuttle, the Ponte Aerea between Rio de Janeiro and Sao Paulo. This operation used an all-Electra fleet from 1975 until 1992, when the government mandated a switch to stage-3 jets. Once the 727s are gone, it will be interesting to see what the next type will be to take over this unglorious role. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Nov 9 00:51:23 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: stevcaisse@aol.com (StevCaisse) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:23 Status: OR In article , sr001b@uhura.cc.rochester.edu (Still Searching . . .) writes: I understand from the marketing folks where I work that many many surveys indicate that Shuttle passengers prefer the wider cabins of the Boeings versus the 2-3 seating configs of the MD80, DC-9, Fokker series aircraft. The 72S' 3 by 3 seating normally allows for an empty seat between the window and aisle passenger (assuming less than a full load). Also, although the 72S is more expensive to operate on a direct operating cost basis (fuel, crew - ETC.), the indirects, (i.e. cost of acquision (the 72S' are most certainly paid for by now)), are much less than other 3 by 3 aircraft like say a 757. Actually, most veteran Shuttle 72S passengers like the aircraft very much. "Kinda like an old easy chair". Steve Caisse From kls Wed Nov 9 00:51:23 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jnedzel@netcom.com (Gared Nedzel) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:23 Status: OR In article sr001b@uhura.cc.rochester.edu (Still Searching . . .) writes: >About 2 weeks ago, I flew ROC -> BOS via LGA. I flew the USAir Shuttle from >LGA-BOS. The inside of the seemed to be nice many years ago when it must >have been new but the years have taken their toll. Why is this aircraft >still the most popular on this route? Why not switch to a more economical >Fokker 100 or soemthing during off-peak hours? Because that would require two sets of aircraft, two sets of crews, two sets of parts, etc. Btw, the USAir shuttle and its aircraft are not owned by USAir. They are owned by the banks that Donald Trump borrowed the money from. USAir has a contract with these banks to operate the shuttle. So the shuttle company itself only has one type of aircraft. The Delta shuttle aircraft and facilities seem to be in better shape than the From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Nicolas Ercan Murat Subject: Re: Rain in the plane References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR > I am investigating measures to prevent or manage the problems associated > with the excessive condensation of water vapor on cold airplane skin and > structure (interior) during long, high occupancy flights. Active > dehumidification of the cabin air is not a desirable solution due to the > operational drawbacks of the equipment and the risks associated with > excessively drying the air (comfort and static problems). Any novel > ideas regarding this topic would be appreciated. Over Condensation is a problem that both Boeing and Airbus aircraft are faced with. When the A340 first came out, their ATA 21 people had to deal with several condensation problems. These mainly occurred at exit doors and could be seen at the pressure gauges of the emergency slides. That problem has been somewhat taken care of. Nevertheless, passengers often see "smoke" coming out of the vents above the bins. Many think it's a fire at first, but it's really just air from the AC system. I've personally been rained on in 747-400. After push back and until we quite a while after take off, you could hear pellets of ice rolling up and down the PCU channels. This occurred on both sides of teh 747's A section (rows 5 and 6 in nose section). The pellets melted of course, and the woman next to me had to cover herself with the board-magazine, safety card, etc... The crew was pretty much not surprized by this as they proceeded to jam cloth napkins in the PCU channel to keep it from leaking on us. On the subject of dehumidification, it is practically impossible to really try that. Boeing as a humidifier in its 747-400 cockpit crew rest. The were thought of removing it in order to save weight and space, but these were quickly done away with when humidity was measured to be 0% in the upper deck. -Bernie From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Ralph Phillips Subject: Re: Rain in the plane References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: Ralph Phillips Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR >I am investigating measures to prevent or manage the problems associated >with the excessive condensation of water vapor on cold airplane skin and >structure (interior) during long, high occupancy flights. Active >dehumidification of the cabin air is not a desirable solution due to the >operational drawbacks of the equipment and the risks associated with >excessively drying the air (comfort and static problems). No no, for god's sake don't make it any drier, active RE-humidification is what's required ! :-) Ralph Phillips From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: tristar500@aol.com (TriStar500) Subject: Re: Reverse Thrust on a 757 References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR In article , saghir@eecg.toronto.edu (Mazen Saghir) writes: >While waiting for our flight to take off at DFW, I noticed that two 757s >landed and had reverse thrust applied before their front landing gears >had touched the ground. Is this standard procedure? I though that reverse >thrust is applied after all wheels are on the ground. The 757 TR requires only that the main gear struts be compressed (Weight On Wheels - WOW). From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Ralph Phillips Subject: Re: Reverse Thrust on a 757 References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: Ralph Phillips Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR >While waiting for our flight to take off at DFW, I noticed that two 757s >landed and had reverse thrust applied before their front landing gears had >touched the ground. Is this standard procedure? I though that reverse thrust >is applied after all wheels are on the ground. To be honest, its not something you think about very much. The nosewheel on the '37 usually kisses the tarmac shortly after the mainwheels, and the reversers take a couple of seconds to travel and a few more to spool up. I think most people start grabbing reverser as soon as the mains are down. I also think that any trim change due to reverse thrust is masked by the major pitch down caused by the spoilers deploying. On the '37 reverse thrust is available if either radio altimeter indicates less than 10 feet, or the squat switch is made From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: edgraf@pipeline.com (Edward Graf) Subject: Re: Reverse Thrust on a 757 References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: The Pipeline Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR In article , Mazen Saghir writes: >While waiting for our flight to take off at DFW, I noticed that two 757s >landed and had reverse thrust applied before their front landing gears had >touched the ground. Is this standard procedure? I though that reverse >thrust is applied after all wheels are on the ground. I fly a 737-300/400 and apply reverse well before the nosewheel touches. I understand on the 737-200, the nosewheel must touch before thrust reverser deployment due to geometry resulting in the thrust reverser contacting the ground with the nose wheel off. Because of the design of the newer aircraft, one can deploy thrust reversers well before nose-wheel touchdown. Ed From kls Wed Nov 9 00:51:24 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: calvano@shadow.net (Calvin D. Harman, Jr.) Subject: Re: Reverse Thrust on a 757 References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Shadow Information Services, Inc. Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:24 Status: OR In article , saghir@eecg.toronto.edu (Mazen Saghir) wrote: > While waiting for our flight to take off at DFW, I noticed that two 757s > landed and had reverse thrust applied before their front landing gears had > touched the ground. Is this standard procedure? I though that reverse thrust > is applied after all wheels are on the ground. Most airliners Apply reverse thrust upon main wheel touchdown. The only exception I know of is the MD-80, which must wait for nosewheel touchdown(due to possible ground contact with clamshell thrust reverser doors). From kls Wed Nov 9 00:51:25 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: dalden@legal.com Subject: Re: Q: Banking angles of airliners? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Legal Recourse(tm) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:25 Status: OR IR>What are "typical" banking angles (roll) of commercial airliners? IR>Please mail to me at rkeen@sunfish.ess.harris.com IR>thanks for any help. Actually, angle of bank is determined by the desired rate of turn. A standard turn is 3 degrees per second (one minute to turn back). The angle of bank needed to maintain a standard rate turn varies with the aircraft's speed. The higher the speed, the higher the angle of bank need for a 3 degree per second turn. In practice, an airliner maneuvering in the terminal area probably requires about 20 degrees of bank to make a standard rate turn. Most pilots should be reluctant to bank more than 30 degrees for passenger comfort reasons. Anything over 60 degrees is technically an aerobatic maneuver. -- Dave Alden Golden Gate University Aviation From kls Wed Nov 9 00:51:25 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jdd@db.toronto.edu (John DiMarco) Subject: Re: Cruise Altitude Schedules References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Department of Computer Science, University of Toronto Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:25 Status: OR hrz090@aixrs2.hrz.uni-essen.de (Dr. Erdelen) writes: >Over here, there are people - of the ecological mindset - who demand a >ban on all flights covering less than 500 or 400 km, on the grounds >that railways would make much more sense for these distances - >ecologically *and* economically. One problem with that idea is that in many cases, short hops are part of a multi-hop flight. For example, a flight from Kingston to San Diego could involve a short hop from Kingston to Toronto, a flight from Toronto to Los Angeles, and a short hop from Los Angeles to San Diego. Because it is usually quite inconvenient for travellers to change their mode of transportation (eg. to use the bus or train), especially in an unfamiliar city, it's much more practical to provide short-hop flights for them. Regards, John -- John DiMarco Office: EA201B Computing Disciplines Facility Systems Manager Phone: 416-978-1928 University of Toronto Fax: 416-978-1931 http://www.cdf.toronto.edu/personal/jdd/jdd.html From kls Wed Nov 9 00:51:25 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: iteam@pipeline.com (Christopher Isham) Subject: Looking for ATR pilots Message-ID: Approved: kls@ohare.Chicago.COM Organization: The Pipeline Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:25 Status: OR In connection with our research into the causes of the crash if Am Eagle Fl 4184, we are very interested in speaking to ATR pilots who can help us understand how the aircraft operates in ice conditions, the effects on lift, stall speeds etc. Please call or e-mail below. Responses will be confidential, if neccessary. Thanks. ABC News Investigative unit 47 West 66 th st. New York NY 212 456-2400 e-mail: iteam@pipeline.com From kls Wed Nov 9 00:51:25 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: laewell@iastate.edu (Lars A Ewell) Subject: Ice Message-ID: Approved: kls@ohare.Chicago.COM Organization: Iowa State University, Ames, Iowa (USA) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:25 Status: OR To Whom it May Concern, I was puzzled to learn that ice on the wings is being considered in the investigation of the recent crash of the American Eagle ATR over Indiana. It was my understanding that icing occured while the plane was waiting on the runway and not while it was in the air such as in the crash at LaGuardia in 3/92. Also, I saw on the MacNeil-Lehr News Hour that the ATR that crashed had the capacity to de-ice the wings in flight (at least that's what I understood). Can anyone shed some light on this? thanx, Lars Ewell From kls Wed Nov 9 00:51:26 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: howiek@aol.com (Howie K) Subject: Aging planes Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:26 Status: OR I'd like to hear some comments on last Thursday's Wall Street Journal article about the safety and integrity of agin (>15 yrs) airlplanes that the airlines are flying. Any thoughts? From kls Wed Nov 9 00:51:26 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: daveremo@aol.com (DaveRemo) Subject: Trying to understand ATR 72 ops in icing conditions Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:26 Status: OR In the hope of doing responsible reporting of the ATR 72 accident in northern Indiana last week I am trying to find ATR 72 pilots who can help understand the effect of icing conditions on autopilot operations. Interviews can be done on or off the record. I am not looking for rampant speculation or theories - there has been enough of that in the press already - just factual information. AE and ATR & the NTSB have been pretty tight-lipped, which only fuels the speculation. E-mail me at DAVEREMO@Aol.com or Call me at 317-633-9888. My name is Dave Remondini. I'm investigative reporter for The Indianapolis Star. From kls Wed Nov 9 00:51:26 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kannan91@iastate.edu Subject: Question relating to turbofan engines Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 09 Nov 94 00:51:26 Status: OR I have reading about the construction of turbofan engines for commercial aviation and have run across two different approaches to building fans : (a) Snubbered fan, and (b) Wide-chord fan. Would it be possible for someone to enlighten me a little more on this subject (in terms of the differences in performance) and/or point me in the right direction. I did try (unsuccessfully) to obtain this information from Rolls-Royce (who have done pioneering work in the design of wide-chord fan engines) but was informed that data of this nature was confidential. Any help would be appreciated. If you feel that answering through the newsgroup would not be appropriate, please send me mail at: kannan91@iastate.edu Thank you, Kannan Srinivasan From kls Sun Nov 20 01:59:00 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: meb4593@ungoliant.ca.boeing.com Subject: Re: Glass Cockpits' Video Rates? References: <01HJ9E8YHKEO0017JD@orcas.iasl.ca.boeing.com> Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:00 Status: OR Ken> The B777 flat panels ... I am not certain that the resolution Ken> of these devices has been talked about in the open literature, so Ken> I do not feel free to discuss it. Suffice it to say that it is a Ken> much finer dot pitch than you see on the average laptop or Ken> workstation display. What amazed me, besides the quality of the "glass", was the incidence angle. (correct term?) In most laptops or watches, the viewable angle is very narrow. The B777 flat panels can be viewed at fairly extreme angles. -- Michael Bain (206) 294-1191 Boeing Commercial Airplane Group Seattle, WA 777 Division - AIMS meb4593@ungoliant.ca.boeing.com From kls Sun Nov 20 01:59:00 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: akrodriguez@tasc.com (A. Kevin Rodriguez) Subject: Re: Glass Cockpits' Video Rates? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: TASC Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:00 Status: OR On computer monitors I notice a refresh-rate-induced screen flicker below 70Hz. Many people would concur. Why does the screen have a slower refresh rate? The lower refresh rate has been claimed to induce fatigue and eye strain in office workers. Has any work been done to evaluate the effects on airline pilots? If so, how many hours of flying in a single day would it take to induce fatigue/eye strain? I'll accept the fact that everybody has differing levels of sensitivity to screen flicker. Is this an issue with long-haul or short-haul routes (i.e., long periods on the deck or several flights a day)? __________________________________________ A. Kevin Rodriguez (AKRodriguez@TASC.com) The Analytic Sciences Corporation (TASC) Reading, Massachusetts From kls Sun Nov 20 01:59:00 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: mculver@halcyon.com (Michael Culver) Subject: water drainage from engines Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: mculver@halcyon.com Organization: Northwest Nexus Inc. Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:00 Status: OR Hi all, I was flying around in that rainy weather that covered the midwest last weekend, and it provoked a thought. As we were climbing out of CVG in a 757 we were in the clouds from maybe 2000 feet up to, judging by the time it took, above 20,000 ft. For most of that time in the clouds, there was a lot of water visible flowing over the wings. There had to be a tremendous flow of water into the engines. How do the engines handle this flow of water and stay running efficiently? Thanks Mike Culver Bellevue, Washington mculver@halcyon.com Former air traffic control specialist at VNY Microsoft SQL Server training and consulting From kls Sun Nov 20 01:59:01 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: tristar500@aol.com (TriStar500) Subject: Re: Rain in the plane References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:01 Status: OR In article , Nicolas Ercan Murat writes: >Over Condensation is a problem that both Boeing and Airbus aircraft are >faced with. The MD-80 also has a bad problem with condensation in the AC ducting. Ask any flight attendant that sits in the aft jumpseats on rotation. The water that has collected in the ducts flows back and comes out of the bugeyes over these seats. The flight attendants are usually the only ones that get the shower but passengers have also been known to get soaked if there is a large accumulation of water. From kls Sun Nov 20 01:59:01 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: fey@hplabsz.hpl.hp.com (Ronald R. Fey) Subject: Re: Rain in the plane References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Hewlett-Packard Laboratories, Palo Alto, CA Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:01 Status: OR Dear Airliners, The air at cruise altitudes of jet airliners has only a few percent humidity. It is extremely dry as most of the water has frozen and settled out. No dehumidifier is necessary on a plane. If there is condensation on the interior skin of a plane, it is from the passengers. Not much you can do to dehumidify them. About all you can do is to limit the airflow over the interior surfaces of the skin. Somehow seal the cabin airflow away from the skin. Or maybe ventilating the space between the skin and the cabin lining with fresh outside air to keep it dry. Ron From kls Sun Nov 20 01:59:01 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: avion@blackbird.db.erau.edu (The Avion) Subject: ANNOUCE: Latest Issue of the Avion Online Available Message-ID: Approved: kls@ohare.Chicago.COM Organization: Embry-Riddle Aeronautical University Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:01 Status: OR The lates issue of the Avion Online, the Internet's first and only Aviation/Aerospace newspaper is now available to the World Wide Web. The URL for the Avion is: http://avion.db.erau.edu/ This issue features a special report on the return of the Space Shuttle Atlantis to operational status in the Space Technology Section. Also included is a review of the Discovery Channel's special show on the people who keep the shuttle flying into space each mission. The Aeronautica Section has a featured article on National Air Charter's DC-3 flights, which is a testament to these 50-year old aircraft. Industry news can be found in the Aviation Trade News section, a regular highlight of this unique Aviation online newspaper. Our weekly Data Technology section this week delves into the multi-media realm of MacroMedia's Macromind Director, a powerful multimedia tool for budding directors. Also available is a multitude of Web sites reviewed in our regular column called Surfin' The Web, including a Monty Python site. Surf in and check out the Avion Online.... -- The Avion Online Newspaper A Embry Riddle Aeronautical University Our Homepage can be found at: The Avion Online email: avion@avion.db.erau.edu From kls Sun Nov 20 01:59:01 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: David Lednicer Subject: ATR-42/72 in icing Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:01 Status: OR Reports of the ATR-72 crash in Indiana indicate that the aircraft was holding for 32 minutes in conditions condusive to icing. The ground temperature reported was 44F and with the standard lapse rate, it was around 10F at 10,000 feet. It was raining in the area, so there was moisture present at altitude. Another ATR pilot reported encountering icing problems in the same area at the same time. A friend of mine at deHavilland Canada tells me that the ATR's aileron aerodynamic balance surfaces, which are not shielded (unlike the DHC-8), do not have anti- or de-ice protection. The fatal crash in Italy in 1987(?) of an ATR was blamed on icing of the balance surfaces, leading to a loss of control. Story is that the same airline came very close to losing a second ATR the same night from the same cause! The Seattle Times is reporting that a ATR was nearly lost over Wisconsin in 1988 due to aileron balance surface icing and that the FAA put out an AD requiring vortex generators to be added to fix the icing problem. There was also mention that having the autopilot flying the aircaft in icing conditions compounds the problem. It seems that a human flying the plane will notice the onset of icing effects on the ailerons, but the autopilot compensates and the first that the pilot knows of the problem is when the aircraft suddenly rolls. My suspicion is that as the balance horns ice, a change in aileron hinge moments is produced, and hence, control load. However, being ailerons, the change is probably symmetric. If the horns don't ice symmetrically or one side sheds it ice and the other doesn't, the imbalance in control loads will cause an uncommanded aileron deflection. ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 From kls Sun Nov 20 01:59:01 1994 Newsgroups: sci.aeronautics.airliners,sci.space.policy Path: bounce-back From: MLINDROOS@FINABO.ABO.FI (Marcus Lindroos INF) Subject: SANGER-another Concorde/Shuttle flop? Message-ID: Approved: kls@ohare.Chicago.COM Organization: ABO AKADEMI UNIVERSITY, FINLAND Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:01 Status: OR Right now, it looks as if the European Space Agency's next major project is going to be Sanger - a two-stage hybrid hypersonic aircraft/small rocket plane. The first stage will be about the size of a Jumbo Jet and capable of mach 7 flight using "ordinary" turboramjets rather than scramjets. The second stage (HORUS) will be carried piggyback on Sanger and separate at an altitude of 45km, it will then fire its engines to achieve Earth orbit. The max.payload is just 3-4t and HORUS will land like a glider, much like the US Space Shuttle. --- There are other contenders for ESA's $15 billion FESTIP project too, but Sanger is "politically correct" since Germany's Messerschmitt-Bolkow-Blohm would be the main contractor. The main competitors (British Aerospace and Reaction Engines Ltd.) will probably be out of the race as long as the British government refuses to contribute money to Europe's aerospace plane program. --- Would Sanger be good? Prominent sci.space.* readers doubt a two-stage-to-orbit spaceplane would bring down launch costs as much as would ballistic single-stage-to-orbit reusable rockets. Sanger could be become just another expensive economic disaster like the Space Shuttle and Concorde before it. But the technical risks (apart from those associated with 1st/2nd stage separation at hypersonic velocities) generally appear to be smaller since propulsion/materials requirements will be less severe than for SSTOs. But there are two crucial questions: -Could Sanger act as a hypersonic airliner?! It could cruise at mach 4-5 and if HORUS was replaced with a passenger compartment pod, Sanger could transport 200-300 people across the Atlantic twice as fast as Concorde. However, new airport support facilities would be required since Sanger's jet engines burn liquid hydrogen, which is difficult to store for long periods of time. Does anyone know the maximum range with full tanks (=100t of LH2)...? -Would it be possible to modify Sanger to serve as a "flying launch pad" for other, more capable but heavier space planes as well...? For weight reasons, most horizontal takeoff-&-landing SSTO spaceplanes have to use a detachable landing gear system (launch trolleys or piggyback launches on aircraft) since lightweight gear cannot support the weight of a fully fueled vehicle. Ukraine's giant Mriya cargo carrier (max payload=275t at mach 0.8) has been proposed, but only two planes have been built so far. Maybe Sanger could be modified to launch heavier, air-breathing spaceplanes like Britain's HOTOL/SKYLON as well? In this case, the craft would separate at subsonic speeds and much lower altitude. The big question mark is how much weight Sanger could support...HORUS has a mass of 95t and the maximum amount of fuel is 100t for a total of ~200t. HOTOL & SKYLON both weight in the 270t range. If Sanger works out well, we will have an affordable hypersonic *AND* space transportation system so the project could be more versatile and economical than other systems... MARCU$ From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: JW6191A@american.edu (John Witherspoon) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: The American University Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR In article kls@ohare.Chicago.COM (Karl Swartz) writes: > >>Never having had the pleasure of flying that route, I don't know what >>airplane is being used. > >Both the USAir (ex-Trump, ex-Eastern) and Delta (ex-Pan Am) Shuttles >exclusively use Boeing 727s. Delta's are all -200 Advanced models, >while USAir uses mostly original -200s, with several of the Advanced >-200s and a few -100s thrown in. I recall reading that when Eastern sold Donald Trump its DC-NY shuttle operation (for far more than it was worth) it made an even bigger fool of Trump by giving him the dregs of the Eastern 727 fleet instead of the aircraft that it had been using to fly the route. Trump then redid the interiors in leather and polished chrome, and USAir chose to keep the interiors since they were relatively nicer than the standard USAir interiors. I don't know if they've been redone since, but observant passengers may still notice the Trump "T" on the seat belt buckles (as is the case on many other planes of other airlines that still carry the Pan Am globe on their buckles). From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: skyrider@cix.compulink.co.uk ("Dave Pellatt") Subject: Airliner performance data... Message-ID: Approved: kls@ohare.Chicago.COM Organization: Compulink Information eXchange Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR Are there any sources of detailed performance information on the net anywhere ? What I'm after is the kind of stuff you'd get in the manufacturer's pilot handbooks; cruise speeds at different weights/altitudes, fuel burn, optimum climb speeds per weight/altitude, stuff like that. TIA, Dave. From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hoel@umiacs.umd.edu (Erik Hoel) Subject: Flight data recorders Message-ID: Approved: kls@ohare.Chicago.COM Organization: UMIACS, University of Maryland, College Park, MD 20742 Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR Given all the recent downed airliner tragedies, I became curious as to how the flight data recorders actually work. Basically, how are they able to record 30 minutes (??) worth of instrument data in such a fashion as to be able to withstand a terrific impact and fire? My uneducated guess is that they "record" the data onto thin metal "tape" in a physical manner (i.e., such as scratching). Of course, the basic problem here is how to rerecord the tape, etc. during the next flight. Perhaps there is a type of magnetic tape that can withstand the heat of a fire - this would be a better solution. Another question - what information is actually recorded? Finally, is it ever the case that the impact is so severe as to destroy the information contained in the black boxes? In any event, I would enjoy hearing more about flight data recorders (and cockpit voice recorders) from the experts in this newsgroup. Signed, Curious in College Park (Erik Hoel:hoel@cs.umd.edu) From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: chuanga@iia.org (Andrew Chuang) Subject: Re: Boeing 777 Wing References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: International Internet Association. Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR Karl Swartz (kls@ohare.Chicago.COM) wrote: : United, the 777 launch customer, still wasn't happy about the weight, : as they wanted non-stop Chicago to Hawaii range. AvWeek reported the the B777 fuel consumption was 5% better than predicted. This is amazing, because I seem to recall that the PW4084 is a few points off of its predicted sfc. If AvWeek report is correct, I wonder if the weight is still a big issue. : >Also, how does the 777 compare performance wise with its competitors, the : >A340 and MD-11? Boeing claimed the B777 has significant seat-cost advantage over both the A330 and the A340, while Airbus claimed otherwise. I saw a Boeing comparison chart, the MD-11 is way out of the league. I think the B777 will be a better performer than the existing A330/340. However, the A340 is looking for a new powerplant, then the B777 and the next generation A340 should be very competitive. : From what I've heard, the 777 has met or exceeded its fuel consumtion : and performance goals from day one, in contrast to the well-publicized : problems with the MD-11. I don't really know how the A340 did, but : shortfalls are fairly common. If I remember correctly, the A340 shortfalls were corrected before the aircraft was certified. : While United originally needed 180-minute ETOPS for : the Hawaiian routes, it would not have hurt too much to keep them : on 48-state/Canada/Alaska routes at first. Now that United has : switched the first batch from domestic to international aircraft, : they can manage with 90-minute ETOPS for trans-Atlantic flights Boeing and P&W are promising 180-minute ETOPS (or 120-, I forgot) at day one. : Virgin Atlantic chose the A340 over the 777 in part because the 777 : would need ETOPS, which Virgin, with no ETOPS track record, would : find hard to obtain. >From what I have read, it seems Virgin is still interested in buying the B777. -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: Boeing 777 Wing References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR In article , kls@ohare.Chicago.COM (Karl Swartz) wrote: > From what I've heard, the 777 has met or exceeded its fuel consumtion > and performance goals from day one, in contrast to the well-publicized > problems with the MD-11. I don't really know how the A340 did, but > shortfalls are fairly common. To follow up and clarify these remarks, there are two levels of performance values. The first is the 'nominal' which is the expected or best guess level. This is normally the median of performance level possibilities. The second level is the guarantee level, usually 5% lower for range estimates. To miss the latter often involves financial penalties stipulated in the contract with the buyer. In the case of the MD-11 the drag was essentially on nominal but both the Pratt & Whitney and the GE engines were high in specific fuel consumption by about 5 to 6% compared to nominal. Douglas has found ways to reduce the drag and the engine manufacturers have recovered part of their deficiencies. The total improvement makes the MD-11 right on its original nominal or 5% better than the guaranteed. The 777 according to Aviation Week of October 10,1994 is right on the nominal which is 5% better than the guarantee. Thus both aircraft meet their nominal predictions. None of this is a real comparison. To obtain that one would need to have the actual specific range (miles flown per pound of fuel) figures at corresponding flight weights and then correct for the number of seats in each airplane. Since the 777 comes later and may have more efficient engines, one would expect it to have some advantage. -- Richard Shevell Email: shevell.leland.stanford.edu From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Boeing 777 Wing References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR >: Now that United has >: switched the first batch from domestic to international aircraft, >: they can manage with 90-minute ETOPS for trans-Atlantic flights >Boeing and P&W are promising 180-minute ETOPS (or 120-, I forgot) >at day one. They can promise anything, but there is no guarantee that the FAA will approve it, and the chances seem slimmer for the JAA. There's also the issue of the airline itself being certified for ETOPS and not just the airframe/engine combination. United is probably in the best situation in this regard, since they not only have ETOPS certification but with the PW4000 to boot. Virgin Atlantic is at the other end, since they have no ETOPS and very little PW4000 experience (just their new 747-400s), plus they are subject to JAA's decision on ETOPS, which may not be as enthusiastic as the FAA. I fully expect the 777 to debut with at least 120-minute ETOPS, but if I were Richard Branson or even Gerald Greenwald, I'd want to have a solid Plan B before plunking down my US$120 million per copy! -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: chuanga@iia.org (Andrew Chuang) Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: International Internet Association. Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR RNA (rna@leland.Stanford.EDU) wrote: : Nor at GE, I have read that they too are having setbacks with the GE90 : certification. Something to do with the new wide-chord fans in the : engine. Can someone in the know please elaborate? GE proposed a controversial modification for the blade-out containment test. GE claimed the conventional test should not be applicable for their unique carbon-composite fan blades. (P&W and R-R use hollowed-titanium blades.) Both P&W and R-R objected to the modification, but FAA agreed with GE. Basically, GE proposed to break off the blade in the flow passage rather than at the root during the test. If one is interested in more details, please refer to Aviation Week. With this modification, GE won't need to further strengthen the casing. Otherwise, the engine may become less competitive due of additional casing weight. (One of the most recent fan blade failure that I can recall is about a year ago. A relatively new [two-year old?] Cathay Pacific B747-400 out of Los Angeles experienced a fan blade failure in a RB211-524H. The failure was contained and the plane safely returned to LAX. R-R could not identify the cause for the failure.) Back to the GE90, the two-week delay of the GE90 certification was not due to the above test. It was mostly because of a test engine failure occurred last month which was reported in details by Aviation Week (who else!). In addition to the fan-containment test, the GE90 still need to pass the 8-lb bird-strike test before the certification. Some of the significant dates for the three engines are listed below, (from my rusty memory, so some dates may not be correct): Engine cert. First 777 flight A/C cert. First revenue flight PW4084 Apr 1994 June 1994 May 1995 June 1995 (UA) GE90 Dec 1994 Dec 1994 Aug 1995 Sept 1995 (BA) Trent800 Jan 1995* June 1995 ? Dec 1995 ? Jan 1996?(Thai) * the Trent 800 was originally scheduled to be certified in March of 95. P.S. I once read that Boeing insisted on R-R having their Trent 800 flown on a flying testbed before it is flown on a B777. I have yet to read about R-R's plan, does anyone know? (The PW4084 flew on a B747 in Oct, 93, and the GE90 flew on another B747 in Nov, 93.) -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Sun Nov 20 01:59:02 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: 777 P&W Failure References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 20 Nov 94 01:59:02 Status: OR > Engine cert. First 777 flight A/C cert. First revenue flight >PW4084 Apr 1994 June 1994 May 1995 June 1995 (UA) First revenue flight is supposed to be c. May 15, 1995. >P.S. I once read that Boeing insisted on R-R having their Trent 800 flown > on a flying testbed before it is flown on a B777. I have yet to > read about R-R's plan, does anyone know? (The PW4084 flew on a B747 > in Oct, 93, and the GE90 flew on another B747 in Nov, 93.) Both the PW4084 and Trent 800 for the 777 were supposed to flight test on 747 #1, which Boeing leased back from the Seattle Museum of Flgiht for the tests. I never heard of it actually happening, though I can't quite imagine it making its maiden flight on a still-uncertified airframe. GE used a 747 that they (GECC) owned and had leased to Pan Am for the GE90 flight tests. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Mon Nov 21 13:18:57 1994 Newsgroups: sci.aeronautics.airliners,rec.aviation.misc Path: bounce-back From: scottk1204@aol.com (ScottK1204) Subject: Rear engined aircraft. (727 DC9 MD80) Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:57 Organization: America Online, Inc. (1-800-827-6364) Someone posted a question on rec.aviation.misc recently that turned into quite a joke. We still did not get an good answer. The writer wanted to know why the engines on 727, DC9, and MD80's seem to be canted nose up 1 or 2 degrees. The discussion turned strange when someone suggested that airliners have the ability to jettison engines by way of exposive bolts in the engine attachments. There are quite a few of the folks who actually believe this. Can someone here give me an answer to the engine question so I can put this issue to rest. Thanks ScottK1204@AOL.COM From kls Mon Nov 21 13:18:57 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rna@leland.Stanford.EDU (Robert Ashcroft) Subject: GE90 comments Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Reply-To: rna@gsb-ecu.stanford.edu Date: 21 Nov 94 13:18:57 Organization: Stanford University, CA 94305, USA A Pratt and Whitney employee sent me the following to be posted: I'm responding by e-mail since my access to the Net is at the moment read-only. Perhaps if you find my comments of interest, you'll post them. GE actually has two separate sets of problems with the GE-90. The one you spoke of involves their petition to change the rules with respect to certification requirements. One requirement is to explosively fail a fan blade while the engine is operating at max power. The traditional way to do this is to blow the blade root apart. P&W has done this and Rolls Royce expects to soon, if they haven't already. GE wants to fail the blade further away from the center of the engine. Much less mass, so less energy released. Speculation is that they gotta have the waiver, because they know they cannot pass the old test. In addition, they are way behind in their experimental test plan, because parts in their test engines keep failing. The most recent major failure was in the lenticular seal between (I think) th\e high and low turbines. I must declare an interest: I'm a 20 year employee of P&W, and I am truly outraged at what GE is trying to do with the FAA on this fan containment test. From kls Mon Nov 21 13:18:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: preston@oberon.pps.pgh.pa.us (Thomas Preston) Subject: Wake Turbulence Experiment Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:58 Organization: Pittsburgh Public School District Hi, my name is Michael Mariani. I'm an 8th grader at Frick ISA in Pittsburgh, and I am conducting a long term science investigation for the Pennsylvania Junior Academy of Science on February 4, 1995. The title of my project is: "_The Effect of Wing Angle of Attack on the Dissipation of Wing Tip Vortices_" I want to know if there is anyone in the field, who could assist me in designing and building a wind tunnel appropriate for an 8th grader to use. In addition, what method(s) could I possibly use in order to collect "quantitative" data, for example, how could I set up a smoke trail, vary the angle of attack, are flaps a factor, etc? Thanks in advance for anyone's assistance; I can be contacted via my science teacher Mr P at the Internet address below. Mike! -- Thomas Preston Science Instructional Team Leader Frick International Studies Academy Internet: preston@pps.pgh.pa.us or 107 Thackeray Street America On-Line: TPSci@aol.com Pittsburgh, PA 15213 USA 412.622.5981 work 412.363.2750 fax Please note: (ich kann Deutsch und Bernerdialekt rede) From kls Mon Nov 21 13:18:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jebright@magnus.acs.ohio-state.edu (James R Ebright) Subject: Re: Glass Cockpits' Video Rates? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: The Ohio State University Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:58 A. Kevin Rodriguez wrote: >On computer monitors I notice a refresh-rate-induced screen >flicker below 70Hz. Many people would concur. Why does the >screen have a slower refresh rate? The efect of the refresh rate on flicker is, in part, determined by the persistence of the phosphor. From a quick viewing of the screens in a 757 (after landing), the phosphors looked a lot more luminious than normal (read cheap!) computer monitors. So they may not have this problem. -- A/~~\A 'moo2u from osu' Jim Ebright e-mail: ebright@bronze.coil.com ((0 0))_______ "'Eternal Vigilance Is The Price of Liberty' used to mean \ / the \ we watched the government - not the other way around." (--)\ OSU | - Bill Stewart, AT&T From kls Mon Nov 21 13:18:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: ATR-42/72 in icing References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:58 In article , David Lednicer wrote: > My suspicion is that as the balance horns ice, a change in > aileron hinge moments is produced, and hence, control load. However, > being ailerons, the change is probably symmetric. If the horns don't ice > symmetrically or one side sheds it ice and the other doesn't, the > imbalance in control loads will cause an uncommanded aileron deflection. Dave, I think you are on to something there. My first reaction was to think you were in a time warp talking about balance horns. That was a normal design procedure in the 20's and 30's. Even the DC-3 did not use horns. Aerodynamically balanced control surfaces on transports from then on used an overhang ahead of the hinge line for balance but always sheltered the overhang in the wake of the fixed surface. But I found a drawing of the ATR 72 in Jane's and they do use a horn. I never worked with horns but they sure look like ice catchers. In addition to changing the hinge moment, is there not a possibility of jamming the control. Limit your ATR-42,-72 flights to the summertime. -- Richard Shevell Email: shevell@leland.stanford.edu From kls Mon Nov 21 13:18:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: BonnieBritt <0006884288@mcimail.com> Subject: B737 Pilots who have experienced yaw or roll difficulties Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:58 I am a writer for the Pittsburgh Tribune-Review covering the loss of Flight 427. I wish to make contact, on or off the record, with B-737 pilots who have experienced roll control problems. I promise to keep your identity secret, under all circumstances, if that is your wish. In western Pennsylvania, call me at 1-800-433-3045. From elsewhere, call 1-800-433-3046. Or message BonnieBritt@mcimail.com Thanks! From kls Mon Nov 21 13:18:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Requests from the press (administrivia) Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: airliners@chicago.com Reply-To: airliners@chicago.com Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 21 Nov 94 13:18:58 Dear readers, I'm looking for your opinions. In the past few months, the traditional press seems to have discovered Usenet, and in particular this newsgroup, as an information resource. I'm delighted that they recognize the expertise that's available here, and hope that it may help improve the quality of the reporting, which has often been dismally inacurate when the subject has been airliners. However, I'm share the concerns of others that opinions expressed here may be taken out of context to fabricate an "expert opinion" that hardly represents anything we'd want to lay claim to. I am also troubled that a regular stream of questions, from the press or elsewhere, may simply drive away those people who have the most to offer the newsgroup. The charter of sci.aeronautics.airliners reads as follows: A moderated discussion group on airliner technology: the design, construction, performance, human factors, operation, and histories of transport-category aircraft. On several occasions I've asked Robert Dorsett, moderator of sci.aeronautics.simulation and also the person who did most of the hard work to create sci.aeronautics.airliners, for his opinion on submissions that simply request information. He notes that the charter says this is a *discussion* group, not an oracle where one can consult the experts. He also has concerns (as do I) that some students may simply try to use the group to have their research done for them. Based on this, I've accepted those submissions which asked questions but which I felt had some potential to generate an interesting discussion. I've rejected many others, usually pointing the sender to a previous discussion in the archives of the newsgroup, to other newsgroups, which may be more relevant, or to more appropriate sources such as Jane's or the local library. Queries from the press seem to fall closer to the latter case, but I've accepted them because I think it's an interesting use of the net. What do *YOU* think about this class of articles in general, and press questions in particular? Are the admitedly fuzzy rules described in the previous paragraph ok? Would you like to see fewer such articles? Would you like to see more of them? One possible alternative might be to keep this stuff out of the newsgroup but to set up a mailing list (or another newsgroup, if anyone wants to go to that degree of effort) where those people willing to answer a variety of questions can help without distracting the main group. If you'd like to express an opinion on this, please send e-mail to airliners@chicago.com. If there is a lot of response, I'll summarize for the group. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Tue Nov 22 00:42:58 1994 Newsgroups: sci.aeronautics.airliners,rec.aviation.misc Path: bounce-back From: rah@netcom.com (Richard Hyde) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners,rec.aviation.misc Organization: NETCOM On-line Communication Services (408 261-4700 guest) Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:58 ScottK1204 (scottk1204@aol.com) wrote: : Someone posted a question on rec.aviation.misc recently that turned into : quite a joke. We still did not get an good answer. Actually, the correct answer was posted several times. Jack Sommers posted: -begin quote- We must be misinformed here at United, in the maintenance training Department. I had been told that on the B-727 the engines have a 4 deg. angle of incidence. The aircraft at normal cruise altitude and speed has a natural nose high altitude of about 3 deg. The reason the engines are canted up is because if airflow over the wings is deflected up toward the stubwing engines. The Boeing 747 (all models) has the same kind of problem with the inboard (2&3) engines. Air in this case is deflected off the nose/raydome and into the (cambered in 2 deg.) engines. -end quote- I, of course, still believe in the explosive bolts. I was once travelling in a 747 that jettisoned *all four* engines in this manner. Took us *forever* to get to our destination. :-) Rick -- ------------------------------------------------------------------------------ | Richard Hyde | RaH@netcom.com | This space intentionally left blank | ------------------------------------------------------------------------------ From kls Tue Nov 22 00:42:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: wolf@accesspt.north.net (Brad Gillies) Subject: Canadian "NTSB" Reports Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: wolf@accesspt.north.net Organization: UUNorth's AccessPoint Service Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:58 I was wondering if there is anyone out there who knows where I can obtain information about Canadian Air Crashes. I am presently compiling information on plane crashes and am having trouble locating info on Canadian incidents and accidents. I do not need full reports, Abstracts and summaries of findings are O.K. Preferably covering recommendations to the F.A.A. and the M.O.T. I also need info on foreign Crashes, Any Commercial airliner anywhere in the world Post 1979. Thank you to all of the people who have already lent their support, any more help would be greatly appreciated -- If it aint broke BREAK IT..... From kls Tue Nov 22 00:42:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rleigh@laurel.ocs.mq.edu.au (Roy Leigh) Subject: CO2 and 747s Message-ID: Approved: kls@ohare.Chicago.COM Organization: Macquarie University Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:58 do commercial airliners have a significant effect on the enhanced greenhouse effect? How much (kg) CO2 and hydrocarbons does a 747 produce while cruising? I assume it is insignificant but can't find any evidence. Thanks Roy From kls Tue Nov 22 00:42:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: irksome@netcom.com (Ian Urquhart) Subject: Re: Q: Banking angle of airliners? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NETCOM On-line Communication Services (408 261-4700 guest) Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:59 When Dave Alden says most pilots are reluctant to bank more than 30 degrees because of passenger comfort, he's probably refering to US airlines. I've flown on several non-US carriers, especially those south of the US border, and those boys really like to throw those planes around; perfectly safely of course but they don't seem to be restrained by namby-pamby considerations like passenger comfort or well-being. They just like to fly! Less chance of the airline being sued by some over-sensitive passenger perhaps? Ian Urquhart irksome@netcom.com From kls Tue Nov 22 00:42:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Keith Steele Subject: Re: Ice References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Delphi (info@delphi.com email, 800-695-4005 voice) Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:59 Lars A Ewell writes: >It was my understanding that icing occured while the >plane was waiting on the runway and not while it was >in the air such as in the crash at LaGuardia in 3/92. >Also, I saw on the MacNeil-Lehr News Hour that the >ATR that crashed had the capacity to de-ice the wings in >flight (at least that's what I understood). Ice can form both on the ground and in flight. At tempertures below freezing not all the water droplets in the atmosphere turn t to ice. The water droplets which are not frozen will freeze when they impact the leading edge of the wings and tail. There are two main types of deicing systems to combat airborne icing. Boots which are used on piston and turboprop aircraft are inflated by the pilot to break off the ice. The main drawback to this system is that if the boots are inflated too early (with less then 1/2 inch of ice) the ice will stretch but not break. Once this happens the boots will no longer function since they are inflating in dead airspace behind the stretched ice and can no longer break the additional accumulation of ice. Boots are rubber strips about a foot wide that run along the leading edge of the wing. They contain 4 or more tubes which inflate stretching the rubber and breaking the ice. The second most common system usually used in jet aircraft is a hot wing. Hot air is bled from the compressor section of the engines and piped to the wing leading edges. The hot air heats the wing to well above freezing preventing the formation of ice. This system is much more reliable and effective than the boot system but generally requires more compressor air than a turboprop engine can provide. Keith Steele B-727 Captain & Flight instructor 75126.1123@compuserve.com From kls Tue Nov 22 00:42:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: chuanga@iia.org (Andrew Chuang) Subject: Re: Question relating to turbofan engines References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: International Internet Association. Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:59 In article , wrote: > >I have reading about the construction of turbofan engines >for commercial aviation and have run across two different >approaches to building fans : > > (a) Snubbered fan, and > (b) Wide-chord fan. > >Would it be possible for someone to enlighten me a little >more on this subject (in terms of the differences in >performance) and/or point me in the right direction. There was an excellent article in Flight International titled "Wide Chord Fan Club". I don't have the date of the article. I believe it was in their 1990 Commercial Engines Directory issue, which is usually published during mid-year. If it is not, then check out the 1991 Directory issue. In a few words, snubbered fan (or shrouded fan) blades are narrow and long (high aspect ratio). The part-span shrouds are there to prevent vibrations. They are usually made of solid titanium. On the other hand, the wide-chord fan (WCF) blades have much lower aspect ratio. Since, there is no blockage in the passage, the fan will pump more air, and the fan efficiency will be higher. Rolls-Royce was definitely the pioneer, and they paid the price. The original design for the RB211-22B (the L1011 powerplant) used composite materials for the WCF. During their development, they encountered many difficulties, and that was a major reason for R-R's bankruptcy. Eventually, they went back to the conventional fan. (Arguably, R-R's bankruptcy resulted in the eventual demise of the L1011.) The first in-service WCF was the RB211-535E4 on the B757. This time, the blades are made of honeycomb-filled titanium (or hollowed titanium). The reason for using light-weight materials is because the WCF are much larger than the conventional blade. If same material is used, then the weight penalty will erase any of the aerodynamic gain. Other in-production or "near-production" large engines that use WCF blades are the RB211-524G/H, V2500, PW4084, GE90, Trent 700/800, and CFM56-7. The GE90 is the only one in the pack that uses composite WCF. -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Tue Nov 22 00:42:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: b18890@vaxb.phx1.aro.allied.com (Arthur Utay) Subject: Re: Question relating to turbofan engines References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: AlliedSignal Engines Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:59 In article , kannan91@iastate.edu writes: > > I have reading about the construction of turbofan engines > for commercial aviation and have run across two different > approaches to building fans : > > (a) Snubbered fan, and > (b) Wide-chord fan. > This discussion will be generic as much of the info is proprietary. Basically, a good fan design should be all airfoil with minimal blockage. Unfortunately, mechanical requirements, such as bird ingestion tolerance and vibratory stiffness have historically required the addition of mid-span snubbers, dampers, nubs, (different names from different companies). Removing the damper not only improves flow through the fan, but it also lowers the manufacturing costs associated with the damper protrusion which interferes with a clean airfoil surface. Rolls-Royce did perfect a wide chord damperless fan made of two titanium halves diffusion bodd together for the RB-211. However, they were VERY expensive. With the advent of new technologies, the wide chord is back on track at all the engines manufacturers. There are some risks however. They include: * Fewer blades per rotor which means a heavier containment projectile which may require a heavier containment system * higher torsional strength requirements for bird ingestion * design requirements to move vibratory signature of the blades AND rotor assembly above any engine resonances * longer blade chord requires larger, longer fan disk, larger bearings, stiffer structure, etc. e.g. more weight All these factors, with proper design, can be minimized, so there can be a significant performance and cost benefit with wide chord blades GE90 will be using composite wide chord blades; I believe other manufacturers are staying with titanium for the present -- ******************************************************************************** Arthur W. Utay, Senior Aerospace Specialist | Your mileage may vary B18890@vaxb.phx1.aro.allied.com | (602) 231-1321 | Cessna 180 N2362C ASEL, Com'l Inst, Comm'l Glider | ******************************************************************************** From kls Tue Nov 22 00:42:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jbn@apple.com (James B Nichols) Subject: turbofan noise Message-ID: Approved: kls@ohare.Chicago.COM Organization: Apple Computer Inc Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 00:42:59 I was wondering, what is the source of that pronounced, droning/growling sound one hears when a widebody is climbing? It seems to start about 30 seconds after liftoff and lasts for about 10 minutes. It is particularly noticable on the DC-10s... From kls Tue Nov 22 12:10:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: David Lednicer Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:41 The nacelles on 727s, DC-9s, etc. are canted nose up because of the downwash created by the wing. You want the inlet highlight plane to be at right angles to the local flowfield, which behind the wing is deflected downwards. DC-9 nacelles are canted up 3 degrees and I believe that the 727 nacelles are canted 3.5 degrees nose up. The nacelles also have a toe angle. On the DC-9, the highlight plane is toed 2 degrees in, but the engine thrust line is toed 2 degrees out. Wing mounted engines also have non-zero cant and toe, to match the local flow field. ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 From kls Tue Nov 22 12:10:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rdd@netcom.com (Robert Dorsett) Subject: Re: Q: Banking angle of airliners? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:41 In article irksome@netcom.com (Ian Urquhart) writes: >When Dave Alden says most pilots are reluctant to bank more than 30 >degrees because of passenger comfort, he's probably refering to US >airlines. I've flown on several non-US carriers, especially those south >of the US border, and those boys really like to throw those planes >around; perfectly safely of course but they don't seem to be restrained >by namby-pamby considerations like passenger comfort or well-being. They >just like to fly! Less chance of the airline being sued by some >over-sensitive passenger perhaps? Or borderine incompetence? Autopilots I'm familiar with limit the bank angle to 27 degrees. The amount of bank permissible is limited by the load permissible at a given weight and airspeed. The higher you fly, the higher the stall speed, and the lower the load factors. Pilots can typically choose from a 1.2 or 1.3g protection schedule, which will permit up to a 40 degree bank. I too have flown on third-world carriers (none south of the border), and most flights have been professional in all respects. -- Robert Dorsett Moderator, sci.aeronautics.simulation rdd@netcom.com aero-simulation@rascal.ics.utexas.edu From kls Tue Nov 22 12:10:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hrz090@aixrs2.hrz.uni-essen.de (Dr. Erdelen) Subject: Re: "Die Zeit" article on Airbus References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:41 Hello, in my previous summary of the "Zeit" article on Airbus technology, I impolitely enough forgot to quote the name of the authors - sorry, authors! They are Bernd Loppow and Stephan Lamby. Also, I have just sent out an ascii-tized version of the article to everyone who boldly wished to venture into reading the German original. Let me know if you don't receive your copy within the next few days. Regards, MArtin Erdelen From kls Tue Nov 22 12:10:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: morten.norby@cen.jrc.it (Morten Norby Larsen) Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:41 In article 1667@ohare.Chicago.COM, hrz090@aixrs2.hrz.uni-essen.de (Dr. Erdelen) writes: [snip snip] >More interesting is that the article does not describe glass cockpit / >fly-by-wire as inherently dangerous, but rather emphasizes problems of >human perception of and reaction to computerization, as well as >insufficient training procedures: "All pilots had blindly trusted >their machines." A slight aside based on hearsay: It seems that the automated/glass cockpit planes - that undoubtedly do drop out of the sky for human reasons every now and then - so far have done it outside of the United States. We're talking about automated planes here, not Airbus vs. Boeing and Douglas. I don't know excactly which planes are included in this category - A320, 757/767, MD11? Does anybody have more precise statistics? Anyway, if it is true, the natural question is: Are there differences in training and/or culture that make American pilots more adapted to the modern planes? Any clues? >Airbus is said to have by now recognized that "pilot training has to >be adapted to the participants' needs, and not vice versa. They, too, >now offer a seminar on communication and teamwork in the cockpit." ...and have been doing it for years, by the way. Morten -- Morten Norby Larsen e-mail: Morten.Norby@cen.jrc.it Joint Research Center telephone: +39 332 78 92 18 Institute for Systems fax: +39 332 78 58 13 Engineering and Informatics From kls Tue Nov 22 12:10:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: *** FILL THIS IN *** References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:41 >A slight aside based on hearsay: It seems that the automated/glass >cockpit planes - that undoubtedly do drop out of the sky for human >reasons every now and then - so far have done it outside of the United >States. >We're talking about automated planes here, not Airbus vs. Boeing and >Douglas. I don't know excactly which planes are included >in this category - A320, 757/767, MD11? If you're counting those, you'd also have to count the A330 and A340 plus the A320 derivatives (A319 and A321). From Boeing, the 747-400, and of course the 777. Beyond those, matters get a little fuzzy -- do you count the second generation 737 (-300, -400, and -500), most of which do have a lot of glass in the cockpit instead of more traditional gauges, along with an FMS, which seems to be closer to the heart of the problem? If so, you also need to count some of the MD-80 models -- the MD-88 for sure, I'm not sure which others. It might also be appropriate to count the A310 and A300-600. My inclination is that it would be fair to exclude the 737 and MD-80 as their cockpit automation is far less sophisticated than the newer aircraft. I'm not so sure about the A310 and A300-600. >Does anybody have more precise statistics? 1 hull loss apiece for the in-service Boeings, though only the 767 was very interesting (a 747-400 ran into Victoria harbor at Hong Kong, a parked 757 was hit by a 737, and a 767 crashed after an in-flight thrust reverser deployment). None for the A319, A321, or MD-11. One each for the A330 and A340 (the A340 was not very interesting, either, as it was a parked Air France aircraft that caught fire) and four for the A320. I should note that there have been at least two in-flight incidents with the MD-11 in which control of the aircraft was lost and then recovered (China Air over the Aleutians and American out of Miami), one of which had at least one fatality. Except for the 757, here are the details of the hull losses of these types: date regn airline c/n l/n model flt dead location ---- ---- ------- --- --- ----- --- ---- -------- 880626 F-GFKC Air France 0009 A320-111 - 3 Habsheim 900214 VT-EPN Indian Airlines 0079 A320-231 IC605 92 Bangalore 910526 OE-LAV Lauda Air 24628 283 767-3Z9(ER) NG004 223 Bangkok 920120 F-GGED Air Inter 0015 A320-111 IT5148 87 Strasbourg 930914 D-AIPN Lufthansa 0105 A320-211 LH2904 2 Warsaw 931104 B-165 China Air 24313 977 747-409 CI605 0 Hong Kong 940120 F-GNIA Air France 010(?) A340-211(?) - - Paris 940630 F-WWKH Airbus (Thai) 042 A330-321 - 7 Toulouse Looking at the A310 and A300-600, there have been six hull losses, though again there were some sitting ducks, in this case a pair of Kuwaiti A300-600s that were destroyed during the war. There have also been two cases of A310s going badly out of control but being recovered (Interflug at Moscow, TAROM at Paris). The details on these losses and incidents: date regn airline c/n l/n model flt dead location ---- ---- ------- --- --- ----- --- ---- -------- 910211 Interflug A310-304 ? - Moscow 910215 9K-AHF Kuwait Airways 327 A300C4-620 - - Iraq 910215 9K-AHG Kuwait Airways 332 A300C4-620 - - Iraq 920729 HS-TID Thai 438 A310-304 TG311 113 Kathmandu 940323 F-OGQS Aeroflot 596 A310-308 SU593 75 Novokusnetzk 940426 B-1816 China Air 580 A300B4-622R CA140 261 Nagoya 940810 HL Korean Air Lines (2/91) A300B4-622R KA 0 Cheju, Korea 940924 TAROM A310 ? - Paris >Anyway, if it is true, the natural question is: Are there differences >in training and/or culture that make American pilots more adapted to >the modern planes? Any clues? First and foremost, I think the sample is simply too small. In many cases (MD-11, for example) there aren't enough planes and they haven't been in service long enough to have a reasonable base of experience. If you ignore the A320 (and include the A319 and A321 as the same), sitting ducks of various sorts, and runway overruns, only the 767 and A330 have losses from the "new" batch, and then only one each. The A310 and A300-600 add three more losses, with the A310 being the only one of the batch to have more than one loss after filtering. Beyond that, US operators account for a relatively small fraction of the fleets for nearly all these types, with the 757 and 767, and maybe the MD-11, being the exceptions. Thus sheer luck would suggest there would be fewer American crashes of most of these types. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Tue Nov 22 12:10:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Andrew Chuang Subject: [Q] normal practice if an engine fail @ t.o.? Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:42 A few weeks ago, I read in an issue of _Flight International_ that a Cathay Pacific Airways' Boeing 747 experienced an engine failure during take-off in Cairns, Australia. The pilot decided not to return to Cairns and continue the flight to Sydney (~ 2.5 hrs?). The airline defended the pilot's decision by saying that Cathay had a spare engine in Sydney. I have no doubt that the B747 can safely fly with three engines. However, what is the usual practice if a pilot experiences an engine failure at take-off on a four-engined aircraft? I would think many passengers would be a little paranoid if they heard strange noises (and perhaps saw fire) from one of the engines during take-off. Furthermore, Cathay's excuse is a little weak, because it should be fairly easy to arrange a swap with Qantas, since both airlines are big Rolls operators. (Last November, a Cathay flight out of LAX experienced a fan blade failure during climb. The passengers on that flight must be glad that the pilot did not continue the flight to HKG because there were plenty of spares available in HKG! 8-) -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Tue Nov 22 12:10:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: chuanga@iia.org (Andrew Chuang) Subject: Re: GE90 comments References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: International Internet Association. Sender: kls@ohare.Chicago.COM Date: 22 Nov 94 12:10:42 Robert Ashcroft (rna@leland.Stanford.EDU) wrote: : A Pratt and Whitney employee sent me the following to be posted: : I'm responding by e-mail since my access to the Net is at the moment : read-only. Perhaps if you find my comments of interest, you'll post them. : : GE actually has two separate sets of problems with the GE-90. The one you : spoke of involves their petition to change the rules with respect to : certification requirements. One requirement is to explosively fail a fan : blade while the engine is operating at max power. The traditional way to do : this is to blow the blade root apart. P&W has done this and Rolls Royce : expects to soon, if they haven't already. GE wants to fail the blade : further away from the center of the engine. Much less mass, so less : energy released. Speculation is that they gotta have the waiver, : because they know they cannot pass the old test. : : In addition, they are way behind in their experimental test plan, because : parts in their test engines keep failing. The most recent major failure : was in the lenticular seal between (I think) th\e high and low turbines. : : I must declare an interest: I'm a 20 year employee of P&W, and I am : truly outraged at what GE is trying to do with the FAA on this fan : containment test. I had a follow-up of Mr. Ashcroft's previous post. It must be lost somewhere in the cyberspace. There should be some clarifications of the above comments by a P&W employee. Note, I'm not trying to defend for GE nor FAA. The GE90 fan blades are distinctively different from P&W's and R-R's. The former are made of carbon composite while the latter two are made of hollowed titanium. GE's argument was based on some probability analyses which FAA agreed. FAA actually solicited opinions from both P&W and R-R. The implication of the rule change is that GE will be able to certify the engine with less material on the casing, hence make the engine weigh less. Since GE90 is the biggest engine of the three, it needs to cut down its weight to be competitive. Whether GE and FAA are compromising on safty, I don't have the expertise to make the call. I would like to point out in one of the letters to the editors of AvWeek or Flight Int'l, a composite "expert" speculated that GE analyses were flawed. I'm not going into the details, if you are interested, read AvWeek. -- ======================================== | H Andrew Chuang chuanga@iia.org | ======================================== From kls Fri Dec 2 02:48:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: ATR-42/72 in icing References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:58 In article , shevell@leland.stanford.edu (Richard Shevell) wrote: > In article , David Lednicer > wrote: > > > My suspicion is that as the balance horns ice, a change in > > aileron hinge moments is produced, and hence, control load ... > Dave, I think you are on to something there. My first reaction was to > think you were in a time warp talking about balance horns. That was a > normal design procedure in the 20's and 30's. Even the DC-3 did not use > horns. Aerodynamically balanced control surfaces on transports from then > on used an overhang ahead of the hinge line for balance ... Pursuant to an E-mail request, balance horns are portions of a control surface that extend spanwise beyond the tip of the fixed surface to which it is attached, and are forward of the hinge line. The purpose is to move the center of pressure of the surface, like a rudder or aileron, forward and reduce the hinge moment that must be applied to hold the surface in a deflected position. They were frequently used on early aircraft including many biplanes in the 20's and the Ford Trimotor. -- Richard Shevell Email: shevell@leland.stanford.edu From kls Fri Dec 2 02:48:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: David Lednicer Subject: ATR icing Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:58 I need to make a correction to my posts about icing and the ATR-42 and -72. It turns out that the aileron aerodynamic balance horn on both aircraft IS anti-iced. ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 From kls Fri Dec 2 02:48:58 1994 Newsgroups: sci.aeronautics.airliners,rec.travel.air Path: bounce-back From: jnedzel@netcom.com (Gared Nedzel) Subject: Re: Shuttle aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Online Communications Services (408-241-9760 login: guest) Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:58 In article JW6191A@american.edu (John Witherspoon) writes: >In article > Trump then >redid the interiors in leather and polished chrome, and USAir chose to >keep the interiors since they were relatively nicer than the standard >USAir interiors. I don't know if they've been redone since, but >observant passengers may still notice the Trump "T" on the seat belt >buckles (as is the case on many other planes of other airlines that still >carry the Pan Am globe on their buckles). The USAir interiors haven't been redone, but they did get rid of the seat belt buckles a couple years ago. From kls Fri Dec 2 02:48:58 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kens@ncd.com (Ken Stoorza) Subject: Re: Glass Cockpit Video Rates References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Network Computing Devices Inc., Mt. View, CA, USA Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:58 I do not have first hand knowledge of the refresh schemes and rates used in these cockpit displays. Here are a few thoughts, however, which will apply once we learn more specific information from others in this newsgroup. 1. These displays are either raster scan, vector scan or a combination of the two. Raster scan is employed in your PC monitor; vector scan (or "stroke" displays) create images by positioning the electron beam at a specific location, turning it (or "them" for color displays) on, deflecting the beam to the stop point and extinguishing it. Such systems present smooth straight lines regardless of rotational position. With higher density raster scan displays and smoothing techniques, very good slightly rotated lines can now be made. This might be a viable, modern alternative to much more expensive vector displays. 2. The phosphor trade off (longer persistence vs. refresh rate) has a few disadvantages when considering slow phosphor: - slow phosphors tend to be less efficient; more beam current is required for equivalent light output. In a high resolution display this is not desireable as increased beam current eventually leads to an effectively larger spot size which compromises resolution. - slow phosphors are not a good choice when moving information is displayed. An undesireable characteristic of long phosphors is "tails" associated with moving objects as the phosphor decays. - when considering color, I do not believe that there are likely choices for long persistence that include all three phosphors. It's tough enough getting good reds and blues as it is without the added constraint of long persistence. I would expect that these cockpit displays use B22, the common monitor phosphor. - phosphor decay is a difficult phenomenon to quantify when considering flicker. Some phosphors initally decay rapidly and then very slowly, yet seem to work well when a long phosphor is desired. The best rule of thumb is to try it and see how it actually performs. 3. With common, regular or high effeciency phosphors, practically everybody can easily see a 60 Hz refresh. This is aggravated by high image intensity and when viewed in the peripheral vision areas (i.e. corners) of the eye. Fewer people can discern 70 Hz and 75 Hz or greater pretty much shuts out everybody. In either a stroke, raster or stroke and raster system, refresh is defined the same way: the time required to re-illuminate any point on the screen. The reciprocal of this time is the refresh rate in Hertz or cycles per second. I left out the possibility of "penetration phosphors" as I expect that modern glass cockpits do not use them. If I am incorrect, I hope the real experts will tell me. Refresh rate considerations are the same, although I would expect that these seldom used phosphors would be less likely candidates for long refresh optimization. -- Ken Stoorza From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners,sci.space.tech Path: bounce-back From: Steven_Hall@mit.edu (Steven R. Hall) Subject: New Master's Degree Program in Aero/Astro at MIT Message-ID: Approved: kls@ohare.Chicago.COM Organization: MIT Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 * * * ANNOUNCEMENT * * * New Master's Degree Program in Aeronautics and Astronautics Massachusetts Institute of Technology Beginning in September 1995, MIT will introduce a new degree program, the Master of Engineering (MEng) in Aeronautics and Astronautics. The goal of the MEng program is to prepare students for an engineering career in aerospace system design and development, in a nine month program. The MEng program is more structured than the existing Master of Science (SM) program, which emphasizes research, usually in a single discipline. The MEng degree will deepen students' understanding in several disciplines important to aerospace engineering. In addition, a major focus of the program will be a new Aerospace Product Design subject and a subsequent team design project, leading to a thesis. The MEng program has been designed to allow matriculation by a graduate of any accredited aerospace undergraduate program. Well-prepared students from non-aerospace undergraduate backgrounds may also apply. We expect that the MEng will be most advanced degree obtained by most of the program's graduates, although it will be possible to pursue a PhD or a more advanced professional master's degree in engineering or management after the MEng. Students who intend to pursue a PhD or a career in research are encouraged to apply for the SM program. The major difference between the SM and MEng programs is in emphasis, not rigor. Therefore, essentially the same admission standards used for the DepartmentUs SM program will be applied to MEng applicants. PROGRAM REQUIREMENTS The MEng in Aeronautics and Astronautics program consists of seven graduate level subjects, plus a thesis. In order to encourage both breadth and depth in several disciplines, students will take subjects distributed among six disciplines. The disciplines are: Structures and Materials Fluid Mechanics Propulsion and Energy Conversion Control and Estimation Humans and Automation Avionics The first three disciplines are associated with the mechanics of aerospace vehicles. The last three disciplines are associated with the information technologies that are increasingly important in aerospace systems. MEng students will take five subjects from three of the six disciplines. In addition, each student will take an advanced engineering mathematics subject. A major focus of the MEng program is the design of aerospace products, meaning vehicles or vehicle subsystems. All MEng students will take a design subject (Aerospace Product Design) in the Fall term. During the Spring term, students will form teams, select a faculty advisor, and begin a design project which will ultimately lead to a thesis for each student. The thesis topic may be selected by the student teams, or may be suggested by faculty, or by companies associated with the program. ADMISSIONS AND FINANCIAL AID As noted earlier, MEng applicants will be selected using essentially the same admission standards as those applying to the SM program. Indeed, students may apply for both programs simultaneously Students will be asked to indicate a preference between the SM and the MEng, but the evaluation will be made with regard to admissibility to the graduate school. Students with a bachelor's degree from an aerospace engineering program and a strong undergraduate record are invited to apply for admission to the MEng program. Well-prepared students from non-aerospace undergraduate backgrounds may also apply. Because of the nature of this program, financial support from MIT in the form of Departmental Fellowships, Research Assistantships, or teaching Assistantships will usually not be available to MEng candidates. Students are encouraged to seek financial aid in the form of company sponsorship, or NSF, DOD or other fellowships. Loans are also available through MIT. Many students without financial aid will find that the MEng program is more attractive than the SM program, since the MEng will generally take only nine months to complete. FOR FURTHER INFORMATION To obtain an application, or to receive more information, contact Ms. Elizabeth Zotos Graduate Office Department of Aeronautics and Astronautics Room 33-208 Massachusetts Institute of Technology Cambridge, MA 02139-4307 Phone: (617) 253-2260 E-mail: zotos@mit.edu or Prof. Steven R. Hall Department of Aeronautics and Astronautics Room 33-105 Massachusetts Institute of Technology Cambridge, MA 02139-4307 Phone: (617) 253-0869 E-mail: Steven_Hall@mit.edu From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners,rec.aviation.misc Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Airplane Group Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 In article , ScottK1204 wrote: >Someone posted a question on rec.aviation.misc recently that turned into >quite a joke. We still did not get an good answer. > >The writer wanted to know why the engines on 727, DC9, and MD80's seem to >be canted nose up 1 or 2 degrees. > >The discussion turned strange when someone suggested that airliners have >the ability to jettison engines by way of exposive bolts in the engine >attachments. There are quite a few of the folks who actually believe >this. > >Can someone here give me an answer to the engine question so I can put >this issue to rest. No, airlines cannot jettison engines in flight. In fact, it usually takes a shift or two to change an engine, there are a lot of complex connections between the airframe and the engine - electrical, hydraulic, pneumatic, and structural. The engines are canted up a degree or so to take into account the downwash from the wing. That is, when the wing generates lift, the flow is turned downward behind the wing, which is where you find the engines on the 727, DC-9, and MD80s. Also the MD90, Fokker 70, Fokker 100, VC-10, Trident, BAC 1-11, Canadair Regional Jet, and nearly every business jet ever built. The engine is aligned with the local flow so that the air will go straight into the diffuser and compressor with no lost energy, and minimal drag. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 In article , David Lednicer wrote: > The nacelles on 727s, DC-9s, etc. are canted nose up because of > the downwash created by the wing. You want the inlet highlight plane to > be at right angles to the local flowfield, which behind the wing is > deflected downwards. DC-9 nacelles are canted up 3 degrees and I believe > that the 727 nacelles are canted 3.5 degrees nose up. The nacelles also > have a toe angle. On the DC-9, the highlight plane is toed 2 degrees in, > but the engine thrust line is toed 2 degrees out. Wing mounted engines > also have non-zero cant and toe, to match the local flow field. I think we said this earlier but here it is again. In addition to the above, an upward inclination of the thrust line provides a little free lift. The loss of thrust is trivial since the cosine of 3 degrees is .99863, and lift is increasd by 5% of the thrust since sine of 3 degrees is .05234. -- Richard Shevell Email: shevell@leland.stanford.edu From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: limerock@aol.com (Limerock) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 In article , scottk1204@aol.com (ScottK1204) writes: For any airplane, the optimum engine orientation tends to be a little bit nose up as the thrust generates a small lift increment Tsin(x), where x is the angle of the thrust vector relative to the flight path, which slightly reduces the amount of lift the wing must provide. This reduces the wing's drag. Little forward thrust is lost, roughly T(cost(x)-1). For aft mounted engines, which tend to be above the c.g., the optimum upwards tilt will be less than for wing mounted engines as they generate a downwards pitching moment which must then be trimmed by the tail. Hope this helps! From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lmnp1@eng.cam.ac.uk (L.M.N. Peiris) Subject: Re: CO2 and 747s Message-ID: Approved: kls@ohare.Chicago.COM Organization: Cambridge University Engineering Department, UK Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 I cannot find any evidence regarding the emission of CO2 and hydrocarbons effecting the greenhouse effect. It is wrong to say that the effect is insignificant since the amount of fuel burn by aircrafts have increased dramatically from the post war years. The jet engines produce more CO2 than its counterparts ,the piston engines. Also the number of aircrafts operating throughout the world has increased. There is now a demand for high power engines to power the new commercial aircrafts. One could say that the amount of CO2 emissions from aircrafts are less than those produced by the global industries. As far as industries are concerned aircrafts' contribution to the greenhouse effect is insignificant. Also the aircrafts' mobility means that their emissions are spread out throughout the earth's atmosphere unlike from factories where the emissions are concentrated locally. **************************************************************** Reply to lmnp1@eng.cam.ac.uk **************************************************************** From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: george0326@aol.com (George0326) Subject: Re: Canadian "NTSB" Reports References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 In article , wolf@accesspt.north.net (Brad Gillies) writes: Try: Transport Canada 4900 Yonge St. Suite 300 North York, Ontario M2N 6A5 or: International Society of Air Safety Investigators (ISASI) Technology Trading Park Five Export Drive Sterling VA 20164-4421 From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: wenne1@aol.com (WENNE1) Subject: Q: Costs to run air freighter? Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 Can I get some rough costs for running a large air freighter between California and New York? I understand the lift of a 747-200 is close to my needs . I am exploring the feasibility of making the freight intermodal, so I would like to know how many 45'x8x9' containers I could stuff in said plane. From kls Fri Dec 2 02:48:59 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: crossley@imap2.asu.edu Subject: Re: turbofan noise References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Arizona State University Sender: kls@ohare.Chicago.COM Date: 02 Dec 94 02:48:59 James B Nichols (jbn@apple.com) wrote: : I was wondering, what is the source of that pronounced, droning/growling : sound one hears when a widebody is climbing? It seems to start about 30 : seconds after liftoff and lasts for about 10 minutes. It is particularly : noticable on the DC-10s... High-bypass turbofans emit noise from two different sources: jet noise and fan loading noise. The core of the engine exhausts a high-velocity jet that produces "jet noise"; this noise is created in the same manner as turbojet on low-bypass turbofan engines on older aircraft (eg Boeing 727 and 737, or DC-9) and has a "roaring", low frequency sound. This sound is created as the high-velocity flow exchanges momentum with the surrounding atmosphere. Newer, high-bypass turbofan engines mix this high-velocity core exhaust with the surrounding slower moving fan exhaust. The net effect is that the jet noise component of these high-bypass turbofan engines is reduced, so that the "fan loading noise" dominates. The fan of a high-bypass turbofan engine has a relatively high loading; it produces a significant amount of thrust per unit area of the fan. Because of this, each blade in the fan (which has an airfoil shape) is operating at a high lift coefficient. Under these conditions, pressure on the front surface of the fan blade (upper surface of the airfoil) is much lower than the pressure on the rear of the blade. This difference in pressure must be resolved at the trailing edge of the blade. Resolving this difference results in a pressure disturbance; this pressure disturbance is the source of the fan noise. This fan noise is often described as having a "siren" or "droning" sound. Because these high-bypass turbofans have a high fan loading and a reduced jet noise, the sound heard by an observer is dominated by the fan noise. Here at ASU, we are almost directly under the take-off and landing paths for Phoenix Sky Harbor airport. I have noticed that the engines on the B-757, B-767, DC-10, MD-11 and Airbus 320 aircraft all have this droning sound. It is easily contrasted to the sound of B-727, B-737 and DC-9 aircraft. I hope this wordy description helps. -- - William A. Crossley, graduate student Department of Mechanical and Aerospace Engineering Arizona State University, Tempe, Arizona 85287-6016 From kls Wed Dec 7 01:15:44 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lespar@aol.com (LesPar) Subject: Re: 747 Fuel Capacity References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:44 In article , gparchom@cln.etc.bc.ca (Gale Parchoma) writes: My airline operates the Boeing B747-100 and the B747-200. Our B747-100's have a maximum fuel capacity of 318,000 pounds, while our B747-200's hold about 344,000 pounds of fuel. Most airlines use fuel capacity measurements in weight rather than a normal fluid capacity measurement. Therefore, while you may expect an answer in gallons or litres, the airline way is either pounds or kilos. If you want to convert to gallons, divide by 6.7. I'm not sure for litres. I hope this helps. Best Rgds. From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lespar@aol.com (LesPar) Subject: Re: extended range twin engine operations References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 In article , allard@iconz.co.nz (David Allard) writes: My name is Les Parson. I am in-charge of developing B757 and B767 ETOPS flight planning for Continental Airlines in Houston, TX USA. We have developed an accelerated ETOPS program for the B757/B767 that is designed to introduce the latter aircraft into service in MAR 95 utilizing the 180 Min ETOPS authority.. At present, we have received FAA authorization to operate the B757-200 on 180 Minute ETOPS authorization after little more than six months of operation. FAA ETOPS is governed by Advisory Circular 120-42A Extende Operations with Twin Engine Aircraft. The "AC" calls for a myriad of technical maintenance requirements in addition to a detailed critical fuel analysis. I would be happy to answer any technical flight planning question you may have. Best Rgds. From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ngupta@nano.mit.edu (Nitin Gupta) Subject: flight cycles Message-ID: Approved: kls@ohare.Chicago.COM Organization: Massachvsetts Institvte of Technology Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 when an airline uses a quick-turnaround scheme on short-haul routes, the aircraft can approach 7-9 flights cycles per day. in the past i remember age being given in total flight cycles. recently it seems that age in year units is more widely used. this leads me to two questions: 1. flights cycle units are more meaningful, no? 2. do quick-turnaround operations reduce the useful operating age of an aircraft? or is this something that maintenance can overcome? with northwest planning on flying some DC-9s into the plane's 40th year, it appears that there is no obvious way to date an airframe. blue skies --------------------------------------------------------------------- Nitin Gupta MIT NanoStructures Laboratory ngupta@nano.mit.edu NeXT Mail Encouraged 617 253 0722 --------------------------------------------------------------------- From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: edswafford@ins.infonet.net Subject: Re: Glass Cockpit Video Rates References: , Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: edswafford@ins.infonet.net Organization: INS Info Services, Des Moines, IA USA Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 this newsgroup. > >1. These displays are either raster scan, vector scan or a >combination of the two. Raster scan is employed in your PC monitor; >vector scan (or "stroke" displays) I missed the start of this thread. It appears there is some question about the type of displays used on commercial aircraft. For the past ten, years I've worked as a software engineer on cockpit displays. The displays used on the 737, 757 and 767 are all basically the same. They are all stroke machines. Any raster you think you may see is really just high speed stroke filling a predefined ares ising a pseudo raster pattern. My understanding the reason stroke is used over raster is for brightness reasons. In high sunlight conditions, a raster display will washout long before a stroke display will. I've been told by hardware types, this is due mainly to energy constraints. i.e. there is only so much energy that can be shot on the screen, and if you can concentrate this energy to a few line instead of the entire screen those line will be much brighter. The refresh rate for these displays is typically 70Hz. I don't know much about the material used in the tubes, but I've been told these tubes are MUCH better than any pc/workstation monitor. Ed Swafford From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: d_peters@uoft02.utoledo.edu Subject: Re: Rear engined aircraft. (727 DC9 MD80) Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: d_peters@uoft02.utoledo.edu Organization: University Of Toledo Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 > >No, airlines cannot jettison engines in flight. In fact, it usually takes >a shift or two to change an engine, there are a lot of complex connections >between the airframe and the engine - electrical, hydraulic, pneumatic, and >structural. Hmmm!! I think i'll go along with the first assertion, but changing an engine doesn't take that long with a good crew doing the work and using a QIC kit (essentially a complete engine with ALL the stuff that goes on the accessory drive plate attached - so you don't have to change them as well). For example: #1 - While cooling my heals on a Mil chrtr at Yokota AB, Jap, watched a C-141 pull up about 1300. Ten minutes later the #3 engine cowling was gone and there were 2 engine carts under the wing, an empty and a full one and maybe 6 people. To keep this brief - they changed an engine and by roughly 1900 the 141 was on its' way. No. 2 - We picked up plane #1 (DC-9) at DTW went to MDW. Enroute had problems requiring shutdown. Picked up another plane (#2), went MDW-DEN-MDW with about a 2.5hr layover DEN. When we got back to MDW we had another aircraft change ..... back to #1 !! Went MDW-LGA uneventfully. In the time we were gone our maintenance people had changed, tested and trimmed an engine - imho a very nice job indeed. For you techno types the shutdown was because of wildly fluctuating EPR, EGT and N1 speeds. Nope, didn't find out what caused it, but i suspect it was something more than just the fuel controller. Hope you all find this anecdote interesting and not a waste of net.bandwidth. Regards -dave From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners,rec.aviation.misc Path: bounce-back From: jjm@swl.msd.ray.com (James Murphy {75881}) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: jjm@swl.msd.ray.com (James Murphy {75881}) Organization: Raytheon Company Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 Also, flying is a balancing act of forces such as lift/weight and CL/CG. Jettisoning an engine would SIGNIFICANTLY alter the CG of an aircraft, probably inducing a nose-down attitude that the control surfaces would lack sufficient authority to overcome. -- The opinion expressed here are mine, not my employers. In fact, opinions are probably the one thing developed at work that employers do _not_ claim ownership of. From kls Wed Dec 7 01:15:45 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:45 >Jettisoning an engine would SIGNIFICANTLY alter the CG of an aircraft, Looking just at pitch, since you mention a nose-down attitude below, the CG would change most dramatically on an aircraft with aft-mounted engines. A typical 727-200 Advanced, for example, has an empty weight just shy of 100,000 lbs, and a MGTOW of around 180,000 lbs. Each JT8D-15A engine weighs just a bit shy of 3,500 lbs, plus a few hundred for accessories and nacelle. That's two or three percent of a typical flying weight, and probably not much more than the effect of a few pax and flight attendents, the latter with meal carts, moving around. >probably inducing a nose-down attitude that the control surfaces would >lack sufficient authority to overcome. Several actual incidents disprove this. The #3 engine departed an American 727 operating DFW-SAN near the New Mexico / Arizona border in the 1980s. The flight crew, believing the engine had merely shut down, continued the flight to San Diego uneventfully. Any change in flight control forces was small enough that they didn't notice the difference. More recently, a Northwest 727 lost an engine over northern Florida. In that case, the crew realized that an engine had detached, but they still had no significant control problems and returned safely to a nearby airport. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jjm@swl.msd.ray.com (James Murphy {75881}) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: jjm@swl.msd.ray.com (James Murphy {75881}) Organization: Raytheon Company Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 In article , shevell@leland.stanford.edu (Richard Shevell) writes: |I think we said this earlier but here it is again. In addition to the |above, an upward inclination of the thrust line provides a little free |lift. The loss of thrust is trivial since the cosine of 3 degrees is |.99863, and lift is increasd by 5% of the thrust since sine of 3 degrees is |.05234. I would be interested in knowing if this is really true... because: Aircraft are design nose-heavy to allow for stall recovery, hence the tail is already trying to go "up". The role of the horizontal stabilizer is push DOWN on the tail and balance this tendancy, hence level flight. Adding "up thrust" will in fact require more angle-of-attack in the horizontal stab to maintain level flight attitude, hence more induced drag. Now, I have to assume that the added efficiency of canting the nacelles up to align with downwash more than overcomes the added drag from the stab, howvever, I can't see where vertical vectors that far from the CG, on that long a moment arm do much to the CG in terms of vertical components. Sort of like trying to carry a see-saw by lifting one end. :-) -- The opinion expressed here are mine, not my employers. In fact, opinions are probably the one thing developed at work that employers do _not_ claim ownership of. From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: JEFFGIVENS@delphi.com Subject: Re: turbofan noise References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Delphi Internet Services Corporation Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 Quoting crossley from a message in sci.aeronautics.airliners : surrounding atmosphere. Newer, high-bypass turbofan engines mix this : high-velocity core exhaust with the surrounding slower moving fan :exhaust. The net effect is that the jet noise component of these :high-bypass turbofan engines is reduced, so that the "fan loading :noise" dominates. I have heard on certain widebodies using GE engines a certain noise at medium to full power that sounds like a giant gearbox running. The growl is so pronounced that it actually sounds like you are next to some sort of huge reduction drive. This noise is even more prevalent from the outside. Next time listening to a Mets game (if they ever play again) and they are taking off over Shea every now and then you hear this distinctive sound. JG...UKT (ABE/PHL) jeffgivens@delphi.com PP-ASEL incl. 4 hrs. B727! From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drchambe@mdhost.cse.TEK.COM (Dennis Chamberlin) Subject: Re: [Q] normal practice if an engine fail @ t.o.? References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: drchambe@mdhost.cse.TEK.COM Organization: Tektronix, Inc., Beaverton, OR. Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 In article Andrew Chuang writes: >I have no doubt that the B747 can safely fly with three engines. >However, what is the usual practice if a pilot experiences an engine >failure at take-off on a four-engined aircraft? I would think many >passengers would be a little paranoid if they heard strange noises >(and perhaps saw fire) I don't know what "normal" procedures are. However, I expect that a fire in flight would be evaluated much, much, much differently than a an apparently normal shutdown of an engine that was not displaying any leakage or obvious signs of damage. >(Last November, a Cathay flight out of LAX experienced a fan blade failure >during climb. The passengers on that flight must be glad that the pilot >did not continue the flight to HKG because there were plenty of spares >available in HKG! The example you inquired about appears to have involved a flight entirely over land. I feel certain this factor was considered in the pilots' decision. From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: lmnp1@eng.cam.ac.uk (L.M.N. Peiris) Subject: Re: [Q] normal practice if an engine fail @ t.o.? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Cambridge University Engineering Department, UK Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 To Andrew Chuang, I think in this situation one has to examine the nature of the failure of the engine. It is quite true to say that the pilot should have turned back to Cairns since that would be the safest option. I think that the pilot did not turn back because the failure may not have been as distressing as in the case of the Cathay Pacific, departed from Los Angeles. In that situation a fan blade separated from no.4 engine causing severe vibrations to the cabin which is not suitable for a long haul flight to Hong Kong. -- Reply to: lmnp1@eng.cam.ac.uk From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: garylapook@delphi.com Subject: Re: [Q] normal practice if an engine fail @ t.o.? References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Delphi (info@delphi.com email, 800-695-4005 voice) Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 Andrew Chuang writes: >Cairns and continue the flight to Sydney (~ 2.5 hrs?). The airline >defended the pilot's decision by saying that Cathay had a spare engine >in Sydney. > >I have no doubt that the B747 can safely fly with three engines. >However, what is the usual practice if a pilot experiences an engine >failure at take-off on a four-engined aircraft? I would think many I don't know what the law is in Australia, but in the U.S. the FAA would bust a pilot for this, and have. They take the position that when an aircraft no longer meets its type certification, such as having many motors, that the aircraft is no longer airworthy. The FARs require that the pilot determine that the aircraft s air worthy. If the aircraft becomes unasirworthy in flight the pilot *must* land at the next available airport where a safe landing can be made. A recent case that was upheld on appeal to the NTSB involved a metroliner. The pilot was flying a deadhead flight with no pax on board. He noticed an erratic oil pressure in one engine so decided to shut the engine down as a precaution so prevent any posible engine damage. He then over flew Laramie Wyoming and continued to Denver, another 131 NM. The FAA suspended his license for reckless operation. The pilot argued that he thaught it was safer to land at Denver but the FAA's expert testified that a landing could have been made safely at Laramie. The judge held (and the NTSB upheld) that the pilot didn't have the option to choose the "safest" airport but he was required to land at the closest airport where a "safe" landing could be accomplished. Let the pilot beware. -Gary- From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: onat@turbine.kuee.kyoto-u.ac.jp (Onat Ahmet) Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Dept. of Information Science, Kyoto University, JAPAN Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 In article morten.norby@cen.jrc.it writes: >> >More interesting is that the article does not describe glass cockpit / >> >fly-by-wire as inherently dangerous, but rather emphasizes problems of >> >human perception of and reaction to computerization, as well as >> >insufficient training procedures: "All pilots had blindly trusted >> >their machines." That really seems to be the reason. Flight modes are frequently mistaken, and if the mistake ends the pilot up in an unfamiliar mode, he might not always know the way to change it back. At a test conducted by NASA on 30 US airline pilots, a large number could not access unfrequently used modes, or could not leave them once entered. This seems to be the reason behind many of the Airbus accidents. One in India for example happened as follows: Just before landing. Pilot is to set the descent rate to -700, but by mistake, sets the altitude to 700. The computer reacts by reducing power to idle, showing the descent bar (I do not know what it is called in practice) way too low on the artificial horizon, and begins automatic descent to set altitude. Pilot, unaware of this pushes the stick further than necessary, following the descent bar on the screen. They realize the problem a couple of hunderd feet agl, but can not figure out the way switch out of the mode properly. And yes, the airpot altitude is actually 900 feet... At least three accidents and one near miss took place with Airbus because the pilots misunderstood aborted landing sequence, resulting in the aircraft stalling at some hundereds of feet AGL, with the nose pointing up as much as 90 degrees. An East German (some time ago)pilot escaped by using manual override for the horizontal stab trim, after stalling four times. >> >> A slight aside based on hearsay: It seems that the automated/glass >> cockpit planes - that undoubtedly do drop out of the sky for human >> reasons every now and then - so far have done it outside of the United >> States. There has been a computer-pilot mismatch crash in 1988 in the US (sorry, no other info...) What we all have to understand IMHO is that planes must be designed based on common pilot instincts, and not vice versa; as is being done nowadays. >> -- >> Morten Norby Larsen e-mail: Morten.Norby@cen.jrc.it Ahmet ONAT onat@turbine.kuee.kyoto-u.ac.jp From kls Wed Dec 7 01:15:46 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hrz090@aixrs1.hrz.uni-essen.de (Dr. Erdelen) Subject: Autonomous Landing Guidance System (ALG) Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 07 Dec 94 01:15:46 In its issue of Nov 2, HPCwire, an e-zine type information service on High Performance Computing affairs, describes a new Autonomous Landing Guidance (ALG) system. According to the article, "[...] ALG enables commercial and military aircraft pilots to land in foggy conditions. ALG provides a clear real-time view of the runway and ground, even in the worst visibility conditions, through the use of a virtual reality heads-up display. Any airplane equipped with the ALG system could land in low visibility conditions (CAT III) at unmodified runways around the world. Only 41 U.S. airports are modified for CAT III landings." [...] The article continues to describe in some detail the computer technology (CNAPS: Coprocessing Nodes Architecture for Parallel Systems, by Adaptive Solutions) used for the system to process "sensor information", but does not mention what type of sensors is used. Can anyone supply more details? (The institutions involved in the project: "Lear Astronics Corp. (Santa Monica and Ontario, Calif.) is serving as the lead member of the ALG consortium, with responsibility for system integration and coordination. Other members of the consortium include Northwest Airlines, United Airlines, the U.S. Air Force and the Maryland Advanced Development Laboratory. Wright Laboratory is leading the government research and development team consisting of Wright Laboratories, NASA Ames, Rome Air Development Center, and associated government laboratories.") [A trial subscription of HPCwire can be obtained by sending an e-mail, with no text in the body, to trial@hpcwire.ans.net. The article quoted above has the reference number 4824.] MArtin Erdelen From kls Wed Dec 14 02:22:36 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: JW6191A@american.edu Subject: 747 forced ocean landings -- survival odds Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:36 Organization: The American University There's a blazing discussion underway in rec.aviation.misc about forced ocean landings of 747s. At issue are the odds of the plane staying in one piece, how long it would stay afloat and whether it would begin to leak through hull weep holes or other openings, whether or not passengers would be better off remaining in the cabin or proceeding to life rafts, etc, etc. Would someone with knowledge of this issue please make a posting to rec.aviation.misc and share some insight? Many thanks! From kls Wed Dec 14 02:22:36 1994 Newsgroups: sci.aeronautics.airliners,rec.aviation.misc Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: 747 forced ocean landings -- survival odds References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:36 >There's a blazing discussion underway in rec.aviation.misc about >forced ocean landings of 747s. At issue are the odds of the plane >staying in one piece, how long it would stay afloat ... The subject of ditching (not specific to 747s) has been discussed at least once in the past in sci.aeronautics.airliners, archives of which are available for anonymous ftp on ftp.kei.com and rascal.ics.utexas.edu. (Updates through the start of this month should be out there shortly if they haven't made it already.) The bottom line, so to speak, seemed to be that an airliner might float for a surprisingly long time. I believe much of this was based on a Pan Am Stratocruiser which was forced to ditch in the Pacific in the 1950s, but don't trust my memory too far. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Dec 14 02:22:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jwm2995@aw101.iasl.ca.boeing.com (James W. McNeil) Subject: Tristar FMC Message-ID: Approved: kls@ohare.Chicago.COM Organization: none Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:37 On a recent flight from HNL to SEA on a ATA L1011 one of the crew commented that the Flight Management System on the Tristar was more "sophistcated" or "ahead of its time" compared to their 757 FMS. Do any visitors to this group have any qualitiative comparisons between the L1011/B757 FMS's? Just curious. -- ******************************************************************************** Jim McNeil - Boeing Flight Simulation Labs ! NOT A BOEING SPOKESPERSON ... etc.! Internet: jwm2995@aw101.iasl.ca.boeing.com ************* REALITY - JUST A SPECIAL CASE OF SIMULATION ********************** From kls Wed Dec 14 02:22:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: suri@biz.ecs.umass.edu (Neeraj Suri) Subject: 777 Flight Control System Message-ID: Approved: kls@ohare.Chicago.COM Organization: University of Massachusetts, Amherst Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:37 Can anyone provide information (top-level/detils) on how the flight control system for the 777 is set up? does it use identical software & hardware on all the six channels, how are the computers interconnected etc. any information would be appreciated. neeraj From kls Wed Dec 14 02:22:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Colin Povey Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Delphi (info@delphi.com email, 800-695-4005 voice) Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:37 Onat Ahmet writes: > That really seems to be the reason. Flight modes are frequently >mistaken, and if the mistake ends the pilot up in an unfamiliar >mode, he might not always know the way to change it back. At a >test conducted by NASA on 30 US airline pilots, a large number could >not access unfrequently used modes, or could not leave them once >entered. This seems to be the reason behind many of the Airbus >accidents. One in India for example happened as follows: I recently took a course in Human Factors Engineering for my masters degree. During the course, I researched four crashes of Airbus planes, all related to incorrect flight modes. In a recent crash, the pilot set a descent glide slope at what he thought was -3.7 degrees. Since he was in the wrong mode, the computer took this to mean a descent rate of 3,700 fpm. He flew into a mountain. As I said, there were four crashes that I was able to find. There may be more. I personally consider this to be an unacceptable rate of crashes, and feel uncomfortable about flying A320/319/321 aircraft. From kls Wed Dec 14 02:22:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:37 >In a recent crash, the pilot set a descent glide slope at what he >thought was -3.7 degrees. Since he was in the wrong mode, the computer >took this to mean a descent rate of 3,700 fpm. He flew into a mountain. It sounds like you're referring to the Air Inter crash into Mt. Saint Odile, better known as the Strasbourg crash. The official report does not identify the mode confusion you describe as the probable cause of the crash. It does list lists several possible causes, with the mode confusion listed as "likely" and the other possibilities ranging from "improbable" to "extremely improbable", but that's not quite the same. Some folks, having been given a "tour" of the A320 cockpit including a demo of the FPA and V/S modes find it very difficult to believe this was the cause of the crash. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Dec 14 02:22:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: T.E.Thacker.Junior@lesueloc.com Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Performance Systems Int'l Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:37 In article , writes: > Just before landing. > Pilot is to set the descent rate to -700, but by mistake, sets > the altitude to 700. The computer reacts by reducing power to > idle, showing the descent bar (I do not know what it is called > in practice) way too low on the artificial horizon, and begins automatic > descent to set altitude. Pilot, unaware of this pushes the stick further > than necessary, following the descent bar on the screen. > > They realize the problem a couple of hunderd feet agl, but can not > figure out the way switch out of the mode properly. > > And yes, the airpot altitude is actually 900 feet... > > At least three accidents and one near miss took place with Airbus > because the pilots misunderstood aborted landing sequence, resulting > in the aircraft stalling at some hundereds of feet AGL, with the nose > pointing up as much as 90 degrees. An East German (some time ago)pilot > escaped by using manual override for the horizontal stab trim, after > stalling four times. When I write rocket trajectory programs, I design in "reasonableness" tests. I don't allow my elevation bug to descend below a certain point no matter WHAT the iterative guidance commands. That way I don't get a horizontally flying "land shark" doing mach five at the tree-tops! I remember the second Saturn V launch that had two engines out in the S-II stage. The guidance wasn't designed to control that kind of loss of thrust and expect a viable boost. It grossly overcompensated and severely lofted the rocket much over the 100 nmi it was supposed to fly towards. When the third stage came alive it's guidance said the equivalent of "Oh-My-God-I'm-Too-High" and proceeded to thrust directly at the ground. At one point, it was actually thrusting BACKWARDS to attain it's target condition. I design in constraints that tell the rocket "OK now, it's not reasonable to go from +80 degress to -80 degrees in 2 seconds - let's constrain it to 0.25 deg-per-sec max rate". Or something like "I'm below 100,000 ft so I must stay above 75 degrees up-elevation". Or, "My Dynamic Pressure is 1000 lbs per square foot now so I must keep less than 0.25 degrees angle-of -attack to the wind". It seems to me they could include ground level info in each autopilot and have the machine reject a request to "cruise" 200 feet below ground level. If Flight Simulator can store every airport, VOR, and feature in the country on two CD-ROMs and "simulate" a crash when you fly into the simulated ground, then a real autopilot should be able to use the same info to keep a pilot from killing himself accidentally. It should also be able to say that 90 degrees nose-up is NOT a reasonable attitude to shoot for. ---------------------------------- Tom "Cant Read/Write Email" Thacker, Jr 404-850-0445 Home ---------------------------------- "Thou shalt maintain thy airspeed, lest the ground shall arise and smite thee". From kls Wed Dec 14 02:22:38 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: wilder@unixg.ubc.ca (Kevin M. Wilder) Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: University of British Columbia, Canada Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:38 Just a question, (I am sorry if this has already been discussed) : Pilot is to set the descent rate to -700, but by mistake, sets : the altitude to 700. The computer reacts by reducing power to : idle, showing the descent bar (I do not know what it is called : in practice) way too low on the artificial horizon, and begins automatic : descent to set altitude. Pilot, unaware of this pushes the stick further : than necessary, following the descent bar on the screen. : They realize the problem a couple of hunderd feet agl, but can not : figure out the way switch out of the mode properly. : And yes, the airpot altitude is actually 900 feet... With all of the computer sophistication in these aircraft, should it not be possible for the autopilot to check the radio altimeter before flying the aircraft into the ground? (I am assuming it has one) I myself program computers as a hobby, and I know that they can be a pain in the *****, but how hard could this be? I am surprised that Airbus was able to certify this aircraft/autopilot combination given the above incident... Regards, Kevin - if something doesn't work, give it a longer name. If it still doesn't work, the new name wasn't long enough. From kls Wed Dec 14 02:22:38 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: jfritz@wvnvm.wvnet.edu (Jeffrey Fritz) Subject: USAir Voice Recorder Transcript? Message-ID: Approved: kls@ohare.Chicago.COM Organization: West Virginia University Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:38 The Pittsburgh TV stations were saying that the transcript from the voice recorder from the fatal USAir Pittsburgh flight was about to be released. Has it been released? Does anyone have a transcription that they could post or send to me? Jeffrey Fritz jfritz@wvnvm.wvnet.edu West Virginia University From kls Wed Dec 14 02:22:38 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 14 Dec 94 02:22:38 In article , jjm@swl.msd.ray.com (James Murphy {75881}) wrote: > In article , shevell@leland.stanford.edu (Richard Shevell) writes: > |I think we said this earlier but here it is again. In addition to the > |above, an upward inclination of the thrust line provides a little free > |lift. The loss of thrust is trivial since the cosine ... > Aircraft are design nose-heavy to allow for stall recovery, hence the > tail is already trying to go "up". The role of the horizontal > stabilizer is push DOWN on the tail and balance this tendancy, hence > level flight. Adding "up thrust" will in fact require more angle-of-attack > in the horizontal stab to maintain level flight attitude, hence more > induced drag. Now, I have to assume that the added efficiency of canting the > nacelles up to align with downwash more than overcomes the added drag > from the stab, howvever, I can't see where vertical vectors that far from the > CG, on that long a moment arm do much to the CG in terms of vertical > components. Sort of like trying to carry a see-saw by lifting one end. :-) Airplanes are not basically designed to be "nose-heavy". However, because airfoils with positive camber are desirable for high maximum lift coefficient and sometimes for best drag divergence Mach number, and because cambered airfoils have a nose down (negative) pitching moment about the aerodynamic center, the wing-body configurations usually have a nose down tendency that must be balanced by the tail. The nose down moment required for stall recovery is obtained by designing the wing-tail combination so that the change in flow when the wing stalls (initially on the inboard sections) causes a pitch down. Ideally the thrust line should go through the center of gravity so that thrust changes do not pitch the airplane up or down. Thus the height of the engines with respect to the c.g. is important. If I remember correctly, inclining the engines slightly upward on the DC-9 put the thrust line very close to passing through the center of gravity. -- Richard Shevell Email: shevell@leland.stanford.edu From kls Thu Dec 15 05:17:36 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: showie@uoguelph.ca (Steve Howie) Subject: Re: USAir Voice Recorder Transcript? References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: showie@uoguelph.ca Organization: Haggisland Inc Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:36 Jeffrey Fritz (jfritz@wvnvm.wvnet.edu) wrote: : The Pittsburgh TV stations were saying that the transcript from : the voice recorder from the fatal USAir Pittsburgh flight was : about to be released. Has it been released? : Does anyone have a transcription that they could post or send : to me? I think the FAA said it was going to be released a few days ago, but it was going to be heavily censored "out of respect for the families of the flight crew" Apparently there were some moments of rather pronounced human suffering on the recording. Scotty -- -- Steve Howie Email: showie@uoguelph.ca NetNews and Gopher Admin. Phone: (519) 824-4120 x2556 Computing and Communications Svcs. Fax: (519) 763-6143 University of Guelph From kls Thu Dec 15 05:17:36 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: d.alan.johnson@larc.nasa.gov (Dave Johnson) Subject: Re: Tristar FMC References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: NASA Langley Research Center, Hampton, VA USA Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:36 > On a recent flight from HNL to SEA on a ATA L1011 one of the crew > commented that the Flight Management System on the Tristar was more > "sophistcated" or "ahead of its time" compared to their 757 FMS. > Do any visitors to this group have any qualitiative comparisons > between the L1011/B757 FMS's? Just curious. The L1011 FMS was the first commercial FMS and predates the 757 by quite a few years (mid '70s), so in that sense it was "ahead of its time", but the system lacked many of the current 757 capabilities. My understanding of the L1011 system was that it was built by a company which eventually gave up on aerospace and went into medical equipment. From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ecla@world.std.com (alain arnaud) Subject: Re: Tristar FMC References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: The World Public Access UNIX, Brookline, MA Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 James W. McNeil (jwm2995@aw101.iasl.ca.boeing.com) wrote: : On a recent flight from HNL to SEA on a ATA L1011 one of the crew : commented that the Flight Management System on the Tristar was more : "sophistcated" or "ahead of its time" compared to their 757 FMS. : Do any visitors to this group have any qualitiative comparisons : between the L1011/B757 FMS's? Just curious. As I recall, the L1011-500 had an active stability system, which meant that the aircraft was basically unstable and required computer control of the ailerons for safe flight. In the late 70's this was way ahead of anyone else in the industry was doing and certainly a precursor of the active controls in the Airbus family and closer to Lockheed in the F117. From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Boeing Commercial Aircraft Group Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 In article , Richard Shevell wrote: >In article , David Lednicer > wrote: > >> The nacelles on 727s, DC-9s, etc. are canted nose up because of >> the downwash created by the wing. You want the inlet highlight plane to >> be at right angles to the local flowfield, which behind the wing is >> deflected downwards. DC-9 nacelles are canted up 3 degrees and I believe >> that the 727 nacelles are canted 3.5 degrees nose up. The nacelles also >> have a toe angle. On the DC-9, the highlight plane is toed 2 degrees in, >> but the engine thrust line is toed 2 degrees out. Wing mounted engines >> also have non-zero cant and toe, to match the local flow field. > >I think we said this earlier but here it is again. In addition to the >above, an upward inclination of the thrust line provides a little free >lift. The loss of thrust is trivial since the cosine of 3 degrees is >.99863, and lift is increasd by 5% of the thrust since sine of 3 degrees is >.05234. Actually, it isn't the thrust line change that gives the increase in lift. It is the fact that the body is flying at a 3 degree angle of attack (about the most you can get without incurring an offsetting drag penalty). The thrust line is then correctly positioned for an efficient cruise attitude. A small difference, I know, but I think it is important. Terry -- Terry drinkard@bcstec.ca.boeing.com "Anyone who thinks they can hold the company responsible for what I say has more lawyers than sense." From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: tristar500@aol.com (TriStar500) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 In article , jjm@swl.msd.ray.com (James Murphy {75881}) writes: >Jettisoning an engine would SIGNIFICANTLY alter the CG of an aircraft, >probably inducing a nose-down attitude that the control surfaces would >lack sufficient authority to overcome. The crews of the 727's that have lost pod engines due to ingesting blue ice and the crew of the DL 737 at D/FW have said that they did not realize that the engines had gone to a different destination. From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: gmartin%f15@mhs.elan.af.mil (Gary S. Martin) Subject: Re: Rear engined aircraft. (727 DC9 MD80) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: 445th Flight Test Squadron/DOE, Air Force Flight Test Center, Edwards AFB, CA Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 In article kls@ohare.Chicago.COM (Karl Swartz) writes: >>Jettisoning an engine would SIGNIFICANTLY alter the CG of an aircraft, [....] >More recently, a Northwest 727 lost an engine over northern Florida. >In that case, the crew realized that an engine had detached, but they >still had no significant control problems and returned safely to a >nearby airport. > There are quite a few cases of airliners coming home without an engine and the flight crew being unaware of its departure from the aircraft. Changes in handling qualities are minor and are not the reason you would never intentionally jettison an engine in flight. The real reason is that there is no requirement to do so and engines cost a lot of money. Gary S. Martin gmartin%f15@mhs.elan.af.mil 445th Flight Test Sq/DOE gmartin@tecnet1.jcte.jcs.mil 95 Flightline Rd Edwards AFB, CA 93524-6020 From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: T.E.Thacker.Junior@lesueloc.com Subject: Re: Engines CAN jettison (Was Rear engined aircraft. (727 DC9 MD80) ) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Performance Systems Int'l Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 In article , writes: > >No, airlines cannot jettison engines in flight. In fact, it usually takes > >a shift or two to change an engine, there are a lot of complex connections > >between the airframe and the engine - electrical, hydraulic, pneumatic, and > >structural. The pilots can't purposely select to jettison an engine but they *CAN* be jettisoned: (1) They are designed in a ditching situation to shear off and flip over the top of the wing rather than dig into the water & pull the wing off. (2) In case of a nasty bad engine fire that is out of control the engine can jettison itself (which happened once on a B747 flight). I don't know how this is triggered (or suppressed) but I know of at least one false jettison (reported in the press as an engine "falling off"). (3) The DC-10 crash in Chicago in the late '70s (that resulted in the grounding of all DC-10's) was because an overstressed connection caused a premature jettison of an engine that flipped over the wing because it was under thrust & was designed to come off that way. The engine jettison caused hydraulic disruptions that deployed a spoiler which the pilot didn't recognize & retract. Coupled with not reducing climb rate, both contributed to the crash. From kls Thu Dec 15 05:17:37 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: kls@ohare.Chicago.COM (Karl Swartz) Subject: Re: Engines CAN jettison (Was Rear engined aircraft. (727 DC9 MD80) ) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Chicago Software Works, Menlo Park, California Sender: kls@ohare.Chicago.COM Date: 15 Dec 94 05:17:37 >The pilots can't purposely select to jettison an engine but they *CAN* >be jettisoned: To me, "jettison" connotes a more decisive act than you suggest. At the risk of starting a debate over razor-fine semantic differences, I checked my handy (American Heritage) dictionary, which says, in part: 1. To cast off or overboard. 2. To discard (unwanted or burdensome articles). While "cast off" suggests an action and not a mindless response, I can't say that either of those definitions really supports my position. Nevertheless, I think you're stretching the meaning of "jettison" quite a bit. Wings can be "jettisoned" too, if you bend 'em hard enough. >(1) They are designed in a ditching situation to shear off and flip over > the top of the wing rather than dig into the water & pull the wing off. This is also for landings on runways without landing gear, but I think the concern is more to keep the aircraft from flipping than it is for tearing off the wings. >(2) In case of a nasty bad engine fire that is out of control the engine > can jettison itself (which happened once on a B747 flight). I don't > know how this is triggered (or suppressed) but I know of at least one > false jettison (reported in the press as an engine "falling off"). On the 747, and many other aircraft, there are bolts or pins in the pylon (called fuse pins on the 747, at least) which are the weakest part of the system. Thus, if the stresses exceed the design limits of the pylon, due to dragging on water (or ground) as in your first example, or due to a severe imbalance, these parts break, allowing the engine to depart the airframe before some more important, like a wing or fuselage (on a 727, for example), breaks. Unless a fire somehow causes such high stress, the engine is staying firmly on the airframe -- there are no explosive bolts or whatnot, and I seriously doubt an airframe could be certified with such devices. >(3) The DC-10 crash in Chicago in the late '70s (that resulted in the > grounding of all DC-10's) was because an overstressed connection > caused a premature jettison of an engine that flipped over the wing > because it was under thrust & was designed to come off that way. The engine separation in the AA 191 crash was not the result of an overstress condition, at least not beyond normal operating limits. However, due to improper maintenance procedures, a flange in the pylon had cracked, and takeoff thrust *was* sufficient to overstress the already-damaged pylon. To describe this as jettisoning the engine surely overstresses the meaning of the word. > The engine jettison caused hydraulic disruptions that deployed a > spoiler which the pilot didn't recognize & retract. Coupled with > not reducing climb rate, both contributed to the crash. No. See earlier discussions of this crash in this newsgroup. The failure caused an uncommanded *retraction* of leading edge slats on the left wing, leading to an asymmetric lift condition which was not reported to the pilots due to inadequate redundancy. The pilot did indeed reduce climb rate, along with airspeed, in accordance with the airline's FAA-approved emergency procedures. However, the slat retraction on the left wing increased the stall speed of that wing beyond the aircraft's airspeed, leading to a stall of the inboard left wing followed by an unrecoverable roll to the left. The pilots did exactly what they were supposed to do, given the information they had. In simulators afterwards, every set of pilots crashed the aircraft. When given a functioning asymmetric slat warning system, pilots successfully flew the simulators to a safe landing every time. -- Karl Swartz |INet kls@ohare.chicago.com 1-415/854-3409 |UUCP uunet!decwrl!ditka!kls |Snail 2144 Sand Hill Rd., Menlo Park CA 94025, USA Send sci.aeronautics.airliners submissions to airliners@chicago.com From kls Wed Dec 21 02:17:40 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: tristar500@aol.com (TriStar500) Subject: Re: Tristar FMC References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:40 In article , ecla@world.std.com (alain arnaud) writes: > As I recall, the L1011-500 had an active stability system, which >meant that the aircraft was basically unstable and required computer > control of the ailerons for safe flight. The -500 has a wing tip extension of about eight feet (each wing). Rather than build an entire new wing, Lockheed designed the Active Control Surface system. This basically consists of a computer, some accelerometers and actuators to control the outboard ailerons. The purpose of the system is to unload the wing because of gusts, turbulence etc. The system can be defered by installing a control rod that adds a trailing edge up bias of about 8 degrees - not desirable due to the addtitional drag this creates - but it can be done so it obviously is not a required system needed to increase the aircraft's stablity. The next time you see a -500 taxi around, take a look at the outboard ailerons. You'll see that they are not faired but are trailing edge up. David G. Davidson AOL Aviation Forum Leader --------------------- Tristar500 tristar500@aol.com From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: hedleyj@wl.aecl.ca Subject: RE: Tristar FMC References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: MIT PLASMA FUSION CENTER Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 Alain Arnaud (ecla@world.std.com) wrote: >As I recall, the L1011-500 had an active stability system, which >meant that the aircraft was basically unstable and required computer >control of the ailerons for safe flight. In the late 70's this was >way ahead of anyone else in the industry was doing and certainly >a precursor of the active controls in the Airbus family and closer >to Lockheed in the F117. This is incorrect. The active control system in the Tristart 500 sensed loads on the wings and deflected the ailerons in such a manner as to keep the lift vector pointing as nearly "straight up" as possible. This improved the cruise performance of the wing somewhat, and, by "dumping" loads outwards along the wing to the wingtip reduced a/c response to gusts and/or rough air, offering a smoother ride. Whether or not passengers were actually able to notice this, I don't know. (Sorry, :-), that should be _Tristar_ 500 !) =============================================================================== Bruce Hedley | AECL Research | Whiteshell Laboratories | " Nostalgia isn't what it used to be " Pinawa, Manitoba, CANADA | | =============================================================================== From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: pete@ide.com (Peter Coe) Subject: Re: Tristar FMC References: Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: pete@ide.com Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 In article , ecla@world.std.com (alain arnaud) writes: > > As I recall, the L1011-500 had an active stability system, which > meant that the aircraft was basically unstable and required computer > control of the ailerons for safe flight. In the late 70's this was > way ahead of anyone else in the industry was doing and certainly > a precursor of the active controls in the Airbus family and closer > to Lockheed in the F117. > Nope. The 500 had longer wings than the other Tristar models, but to save weight the wings were not substantially strengthened. To be able to deal with the added stress the longer wings caused, the FMS had Active Gust Alleviation (well it was called something like that). This used the ailerons as flaps to reduce the wing load in the event of turbulance. The first 500's were delivered without the wing extensions, because the FMS had not been finished. BA sent back a couple to have the extra length put on, and the FMS to be extended. One respect that the Tristar was quite advanced was that it was delivered with Cat 3b landing capability from day one. BEA (British European Airways, one of the airlines that went on to become British Airways), required this capability for the northern european winters. I think the Tristar was cleared for Cat 3c, but no airports are! Anyone know what the difference is between the categories. 3c is zero/zero, and 3b is something like 50feet vertical/200 feet horizontal, but I'm not really sure of the figures. The only time that a landing has freaked me out was a cat 3b landing when the first thing I knew we were on the ground was when the thrust reversers and brakes kicked in. I didn't feel the touch down, and as I was over the wing, the visisbility was such that I couldn't see the ground. Very Very impressive. I really miss the Tristar. -- -- Peter Coe -- Interactive Development Environments -- 595 Market Street, 10th Floor, San Francisco CA 94105 -- +1 (415) 543-1314 x238 Fax: +1 (415) 543-0145 -- From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: bullwrite@aol.com (BullWrite) Subject: Re: "Die Zeit" article on Airbus (longish excerpts) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 In article , kls@ohare.Chicago.COM (Karl Swartz) writes: With all due respect regarding the comment about the Air Inter crash; why is it "very difficult" to believe that mode confusion was the cause of the crash? After all, didn't the cockpit crew of a Northwest MD-80 forget to extend the wing flaps (via mechanical actuation) just prior to take-off causing a crash and the deaths of some 160 passengers? R. Solene From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Pete Mellor Subject: Re: 747 forced ocean landings -- survival odds References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 > There's a blazing discussion underway in rec.aviation.misc about > forced ocean landings of 747s. At issue are the odds of the plane > staying in one piece, how long it would stay afloat and whether it > would begin to leak through hull weep holes or other openings, > whether or not passengers would be better off remaining in the cabin > or proceeding to life rafts, etc, etc. A few thoughts:- The hull is designed to withstand positive pressure *inside*. Once under water (assuming it would sink *before* the water filled the cabin), every device for keeping pressure *in* would work "the wrong way round". (The plug doors would be forced open by the external pressure, for example.) If passengers donned life-jackets, they could presumably bob up to the surface, *provided they could get out of the doors against a rush of incoming water*. (Not a cheerful survival prospect, IMHO.) The main question is, how long would it float? I have not flown on a 747 recently, but I did fly on a 737-400 last week. The safety card shows the aircraft floating on the water after ditching, with the passengers sitting calmly on the wings in their life-jackets after making an exit through the over-wing doors. I was sufficiently surprised the first time I saw this to ask one of the cabin staff if the 737-400 really was designed to float, but I didn't get a particularly authoritative answer. > Would someone with knowledge of this issue please make a posting > to rec.aviation.misc and share some insight? Please feel free to repost this, if you think it is useful. I would be interested in any opinions on the 737's qualities as a flying boat! Regards, Peter Mellor, Centre for Software Reliability, City University, Northampton Square, London EC1V 0HB Tel: +44 (171) 477-8422, Fax.: +44 (171) 477-8585, E-mail (JANET): p.mellor@csr.city.ac.uk ----------------------------------------------------------------------------- From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: Albert Thomas Bozzo Subject: Re: 747 forced ocean landings -- survival odds References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 [Karl, if you'd rather kill this thread, I'd understand completely. I can, however, probably find cites for the DC-8 anecdotes without too much trouble if desired... --Tom] On 14 Dec 1994, Karl Swartz wrote: > The bottom line, so to speak, seemed to be that an airliner might float > for a surprisingly long time. I believe much of this was based on a > Pan Am Stratocruiser which was forced to ditch in the Pacific in the > 1950s, but don't trust my memory too far. > Your memory is correct in that there were at least two (relatively) successful Stratocruiser ditchings -- the other that I'm thinking of was in Puget sound and may have involved a Northwest aircraft. Again, this is entirely from memory... Turning to significantly larger aircraft, while trawling for data on a matter unrelated to airline accidents, I came across news items regarding a pair of DC-8 accidents circa 1969-70. (Unfortunately, I did not get citations at the time.) In one, a JAL DC-8 landed well short (miles) of SFO. The circumstances of the landing notwithstanding, the aircraft stopped in one piece and settled into mud. The aircraft was not in danger of sinking per se and was evacuated because of leaking fuel. The aircraft was extracted from the mud, found to be in good condition despite over two days of salt water immersion, and was repaired and returned to service, as I recall. If anyone knows more about the circumstances of the JAL mishap and/or its aftermath, I'd be interested to hear about it, or be pointed to an appropriate source. In the other incident, a SAS DC-8-62 ditched in the Pacific off Los Angeles. (A UAL 727 had crashed close-by not long before this accident, if this jars any memories.) This was one of a series of closely-spaced mishaps, which merited a story in AW&ST featuring an astonishing photograph of the aircraft. The fuselage had split just aft of the wing and the tail section sank (apparently most of the fatalities were trapped in this part of the aircraft). However, the rest of the plane floated for quite some time; it sank during an attempt to tow the wreckage to shore. > >There's a blazing discussion underway in rec.aviation.misc about > >forced ocean landings of 747s. At issue are the odds of the plane > >staying in one piece, how long it would stay afloat ... > In a nutshell, there's no reason a controlled water landing cannot in principle be survivable (this presumably abstracts the earlier s.a.a. discussion of ditching). However, the rafts, probably unlike the plane, are designed to float indefinitely. Except in extraordinary circumstances I don't think I'd need much convincing to abandon ship. --Tom bozzo@wam.umd.edu Department of Economics University of Maryland at College Park From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: ctillier@leland.Stanford.EDU (Clemens Emanuel Tillier) Subject: Re: Engines CAN jettison (Was Rear engined aircraft. (727 DC9 MD80) ) References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Stanford University, CA 94305, USA Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 >>(1) They are designed in a ditching situation to shear off and flip over >> the top of the wing rather than dig into the water & pull the wing off. Karl Swartz wrote: >This is also for landings on runways without landing gear, but I think >the concern is more to keep the aircraft from flipping than it is for >tearing off the wings. How can an engine shear off and go *over* wing? In situations such as described above, I would expect the engine wreckage to go *under* the wing. (Especially for the water landing.) Also, what is meant by "flipping" the aircraft when landing without gear? Thanks, Clem Tillier Stanford, California, USA ctillier@leland.stanford.edu From kls Wed Dec 21 02:17:41 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: shevell@leland.stanford.edu (Richard Shevell) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Followup-To: sci.aeronautics.airliners Organization: Stanford University, Dept. of Aero/Astro Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:41 In article , drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) wrote: > In article , > Richard Shevell wrote: > >I think we said this earlier but here it is again. In addition to the > >above, an upward inclination of the thrust line provides a little free > >lift. The loss of thrust is trivial since the cosine of 3 degrees is > >.99863, and lift is increasd by 5% of the thrust since sine of 3 degrees is > >.05234. > Actually, it isn't the thrust line change that gives the increase in lift. > It is the fact that the body is flying at a 3 degree angle of attack (about > the most you can get without incurring an offsetting drag penalty). The > thrust line is then correctly positioned for an efficient cruise attitude. > A small difference, I know, but I think it is important. Maybe it is just a way of looking at it, but a positive incidence of the thrust line with respect to the flight direction does in fact provide lift equal to the thrust times the sine of the thrust incidence angle referred to the flight direction. This discussion depends on the definition of thrustline incidence. The thrustline incidence is generally defined with respect to the fuselage reference line which is an arbitrary line in the fuselage defined, in a transport, to be parallel to the floor. Normally one selects the wing incidence such that the fuselage floor is level in the usual cruise configuration. Therefore the thrust does provide a lift if there is a positive incidence angle. Flight attendants do not appreciate puishing 100 lb. carts uphill so a substantial airplane incidence in cruise, defined by the fuselage reference line, is a negative, although it has happened sometimes. In any case if the thrust has a positive incidence with respect to the reference line, a positive contribution to lift occurs compared to a zero incidence thrust line. -- Richard Shevell Email: shevell@leland.stanford.edu From kls Wed Dec 21 02:17:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: limerock@aol.com (Limerock) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:42 In article , shevell@leland.stanford.edu (Richard Shevell) writes: Sorry, there is no way that the thrust vector of the DC-9 goes through the c.g.! You were correct in your previous note regarding the thrust inclination - it is favorable even though the tilt creates a slightly more nose down moment which must be trimmed out. From kls Wed Dec 21 02:17:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: limerock@aol.com (Limerock) Subject: Re: Rear Engined Aircraft References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: America Online, Inc. (1-800-827-6364) Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:42 In article , drinkard@bcstec.ca.boeing.com (Terrell D. Drinkard) writes: Terry, this is Paul M. The body attitude at cruise creates a very small amount of lift but a significant nose up pitching moment thus reducing lift and drag losses due to trim. The thrust vector is tilted upwards for the reasons given by myself and others in previous notes. From kls Wed Dec 21 02:17:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: eph72385@Rosie.UH.EDU Subject: Loss of an engine Message-ID: Approved: kls@ohare.Chicago.COM Reply-To: eph72385@Rosie.UH.EDU Organization: University of Houston Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:42 Hi, I am curious how a crew, most notably the pilots, could not notice the loss of an engine in flight. Are there not sufficient warning systems for engines that would go off if an engine were to come off? Somthing like a loss of oil pressure, unstable fuel flow, leaking hydraulic fluid, something? Turbine speed? Temperatures? I am certainly no expert on commercial, or any aircraft for that matter. I just find it extremely hard to believe that it would simply go unnoticed. -Phil Phil Hyde Department of Computer Science The University of Houston From kls Wed Dec 21 02:17:42 1994 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: larryb@ssd.fsi.com (Larry Bellmard) Subject: Re: 777 Flight Control System References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: FlightSafety-SSD, Tulsa, OK, USA Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:42 In article suri@biz.ecs.umass.edu (Neeraj Suri) writes: Can anyone provide information (top-level/detils) on how the flight control system for the 777 is set up? does it use identical software & hardware on all the six channels, how are the computers interconnected etc. any information would be appreciated. neeraj Here is a simplified description of whats going on. The flight control system is primarly made up of: 3 - Primary Flight Computers (left, center & right PFC's) 4 - Actuator Control Electronics (left1, left2, center & right ACE's) 3 - Autopilot Flight Director Computer's (left, center & righ AFDC's) 2 - Airplane Information Management System (left & right AIMS) These LRU's communicate over 3 bi-directional ARINC629 busses (there are only three "channels"). For the most part the matching LRU's run the same software and the hardware would be identical. The AIMS is the "mother", providing communication "links" between any LRU's needing data from any other LRU (if the two LRU's are on the same bus, communication may take place between the LRU's). So with a ton of inputs, the PFC determines where the control surfaces should be and tells the ACE to move the surface. When the Autopilot is engaged, the AFDC, then talks to the PFC and then the PFC talks to the ACE. Sounds simple, try simulating it!!!! -- Larry Bellmard FlightSafety International Senior Engineer Simulation Systems Division D69-Autoflight Tulsa, OK USA larryb@dev1.ssd.fsi.com 918-251-0500 From kls Wed Dec 21 02:17:42 1994 Newsgroups: sci.aeronautics.airliners,sci.engr.civil,sci.physics.electromag Path: bounce-back From: swormley@thr1.cnde.iastate.edu (Sam Wormley) Subject: Call for Papers - 22nd Annual Review of Progress in QNDE Message-ID: Approved: kls@ohare.Chicago.COM Organization: Center for Nondestructive Evaluation Sender: kls@ohare.Chicago.COM Date: 21 Dec 94 02:17:42 Papers are sought for the 22nd Annual Review of Progress in Quantitative Nondestructive Evaluation to be held on July 30 - August 4, 1995, at the University of Washington, Seattle, Washington. The Review will be hosted by the Center for NDE, member of the Institute for Physical Research and Technology at Iowa State University. URLs: http://www.cnde.iastate.edu/ http://www.cnde.iastate.edu/qnde.html Verbal and poster sessions will be arranged, as in past years, that emphasize both the basic science and early engineering developments in quantitative NDE and closely related technologies such as materials characterization and process control that utilize quantitative NDE and closely related technologies such as materials characterization and process control that utilize quantitative NDE techniques. Thus, categories of the Review will include advances in: 1. Fundamentals of all QNDE methods (field-flaw interactions and field-property relations, scattering, probability of detection, inverse methods and their application to flaw sizing and property measurement, process models, reliability of measurement and component inspectability), 2. Flaw imaging and reconstruction, image analysis, all techniques, 3. Signal processing methods including application of advanced techniques to QNDE, 4. Sensors, transducers, and probes for flaw detection, material property measurement, and process control, 5. New and emerging QNDE techniques (e.g. NMR), 6. New QNDE instruments and systems, 7. QNDE reliability and inspectability, 8. Materials characterization (properties, stress, processes, weldments, corrosion, others), 9. QNDE for advanced materials (composites,electronic materials and devices, ceramics), 10. QNDE of civil structures and materials, 11. QNDE in manufacturing design and process control. Prospective authors are requested to prepare a 200 word (or less) abstract. The abstract should be typed and include the title, author (s) and affiliation before the body of the abstract. Abstracts and the QNDE Submittal Form are to be submitted to: Attn: ABSTRACT ENCLOSED Center for NDE Iowa State University Applied Sciences Complex II 1915 Scholl Road Ames, IA 50011 Deadline: April 28, 1995 Questions should be directed to Connie Nessa or Sarah Kallsen at (515) 294-9749 or FAX (515) 294-6368. Your abstract will be reviewed by a program committee, and you will be informed by May 22, 1995, of its acceptance and whether your presentation will be in a verbal or poster session for the Review. As in the past, arrangements have been made to publish the Proceedings as a hardback volume. Details of manuscript preparation will be sent to you at the time you are notified of acceptance of your abstract. Manuscripts will be due on September 1, 1995. Donald O. Thompson Director, Center for Nondestructive Evaluation and Distinguished Professor, Aerospace Engineering and Engineering Mechanics