From kls Thu Jan 25 00:55:05 1996 Newsgroups: sci.aeronautics.airliners Path: bounce-back From: rickydik@ix.netcom.com (Ralph Ricks ) Subject: Re: CSAT III Landing Control References: Message-ID: Approved: kls@ohare.Chicago.COM Organization: Netcom Sender: kls@ohare.Chicago.COM Date: 25 Jan 96 00:55:05 In adrian@airmail.net (adrian Reedy) writes: >On 10 Jan 96 02:01:42 , bareynol@cca.rockwell.com (Brian A. Reynolds) >wrote: > Note that no CAT III approaches may be initiated with any required >air or ground component inop. A failure at any point requires a >missed approach. Also, no autopilot disconnects at DH with a manual >landing are permitted underr CAT III. By definition, they are >autoland only. Hi Brian! One minor point here: a fail passive autoland just gives the plane back to the pilot if there is a failure at any time. A fail operational autoland system continues the approach and landing if there is a failure at a point low in the approach. The light twins: MD-80 and 737-3,4,500 are CAT IIIA fail passive. The 757, 767, 747-400, 777, MD-11 and L-1011 are all CAT IIIB fail op. The DC-10 was fail op when it worked. > > I'm not familiar with the CAT III approval for retrofitted 727s with >the heads-up display. I don't -think- they have autoland capability. With that neat Flight Dynamics Heads Up Guidance Sytem, they don't need autoland. The pilot flies the plane to a CAT IIIA landing. Actually, some of the latest 727-200 were CAT IIIA autoland equipped. I believe some carriers are using it. There is talk of doing CAT IIIB in the 737-3,4,500 using the combination of the fail passive autoland and the HGS. >As a CAT IIIc landing would require a fully controlled nose steering >|mechanism, are there any commercial aircraft certified for this? > Early in the 757 career, BA did 1,000 instrumented autolands without a single failure. That helped qualify the BA 757 for CAT IIIC, but they received IIB rating only. There is just no guidance to get off the runway once the plane has stopped. Ralph