Re: Boeing 777 - Totally Irresponsible?

Date:         07 Jan 97 07:20:18 
From: (Robert Dorsett)
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
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In article <airliners.1997.130@ohare.Chicago.COM> writes:
>Peter Ashwood-Smith wrote:
>>     I also find the lack of feedback in Airbus systems to be a
>> poor design choice. So much useful information can be obtained
>> by the feel of the controls the only reason I can think of for
>> eliminating it is weight/cost savings.
>We've gone through this one before. This is utterly false.
>Airbus provides DIFFERENT feedback than Boeing does. Boeing simulates
>mechanical feedback on the controls while Airbus provides more
>complete information on its screens as well as audible feedback.

You call that feedback.  I call those "kludges."  Audio alarms and
annunciations are easily filtered out, and physical/tactile feedback (in
moderation) is far superior to peering at a little 7.25" display and looking
for the white dot which reflects whatever it is the airplane thinks it's
doing.  Assuming the white dot is shown in the current display mode, that

Pilots get used to the Airbus approach.  After a bunch of training, re-
training.  Many love it (some pilots love the DC-10, too, though, so pilot
surveys are clearly not all they're cracked up to be :-))

It's absurd to claim, though, that there is *appropriate* feedback,
given the fact that three (and perhaps alli [I don't count the A330
accident]) of the crashes involved sequences in which the crew *did not
know what the properly functioning airplane was doing*.  (and our dear friend
Bernard Ziegler is apparently getting sued for "involuntary homicide" in
his role in the design of the displays which allegedly contributed to the
Strasbourg crash :-))

Apparently, many of the factors leading to the early spate of crashes have
been fixed in both software and training, given the fact that we haven't
seen another crash in a couple of years.  This is obscene, yet another
kludge, proof that "going your own way" and developing unique aircraft
interfaces is not in the public interest.

>You can gain much more USEFUL information from the displays which give
>you real and accurate measures, as opposed to "what you *feel* when you
>move the wheel".
>The one area where there seem to be complaints is the throttle on Airbus
>not matching any changes made by the computer.  Do pilots leave their
>hands on the throttle throughout the flight to notice if engine throttle
>is being changed by the computer ?
>>From my point of view, I have no problem on MS Flight simulator looking

Aaaaah, the real problem raises its ugly head.  You think flying an airliner
(never mind an airplane) is like flying a personal computer.

>at the screen to see what my throttle is at and pressing certain keys to

Yeah, must be nice to get all the information you want, sitting in a
comfy chair with less than 20 degrees of eye travel in your scan.
Go out and rent a real simulator sometime and try to repeat that scan.
You'll notice a few problems: it becomes REAL.  You suddenly have to move
your head.  You have to look out the window.  You have to monitor your
copilot.  You have to deal with tubulence and wind.  You have to deal with
air traffic control.  You need to monitor your systems and deal with
interruptions.  Oh, yeah.  Do that four days in a row, eight hours a
day.  Make sure your flights occur every 18 hours, so your circadian
rhythms get disrupted, and you're dead tired.

THEN talk to us about "appropriate feedback."  Pilots don't need some
dazzling spectacle of intellectually correct integration requiring
weeks of training.  They need something so pathetically simple that a
child can fly it.  If movable autothrottles are what turn pilots on, so
be it.

>increase/decrease it to the levels I want. This way I keep my eyes on
>the main display. Perhaps this is how it is done on the Airbus with
>actual and precise throttle indication displayed on the pilots main
>screen with the physical actuator acting like a glorified "+" and "-"
>keyboard keys to increase/decrease throttle till it gets to the desired
>value as displayed on the screen.

You really don't know, do you?

Robert Dorsett                         Moderator, sci.aeronautics.simulation