Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!ames!skipper!shafer From: shafer@skipper.dfrf.nasa.gov (Mary Shafer) Newsgroups: sci.space.shuttle Subject: Re: Shuttle computers break down during glide tests Message-ID: Date: 5 May 91 02:48:54 GMT Sender: shafer@skipper.dfrf.nasa.gov Distribution: sci.space.shuttle Organization: NASA Dryden, Edwards AFB, CA Lines: 52 In-reply-to: stanfiel@testeng1.misemi's message of 3 May 91 15:27:20 GMT In article <7800@testeng1.misemi> stanfiel@testeng1.misemi (Chris Stanfield) writes: >In article <74602@eerie.acsu.Buffalo.EDU> stein-c@acsu.buffalo.edu (Craig Steinberger) writes: >> >>I remember reading that the autopilot/autoland was accurate to a >>tolerance of about 20 feet or so. This tolerance is acceptable in flight >>but a mistake of 20 feet while landing can put you underground. However, >>I do recall some tests of an autoland capability being tested on some >>airplane by NASA (LaRC?). That was in an AW&ST some time ago. This has been tested in various support aircraft, including Dryden's Jetstar, but has not been tested in the Shuttle. My understanding is that it will be used only in extreme emergency, like the commander and pilot both being incapcitated. After watching Steve Nagel fight the extremely gusty wind all the way around the HAC and on final (he landed short and slow because of it), I'm not convinced that autoland is all that red-hot, unless the system is extremely robust. Of course, if he'd used autoland and landed so short, some netters would be whinging about how he abdicated his responsibility by not flying it himself. >There have been functioning autoland systems in existence for 20 years >- I know because the first engineering job I had was working on a >simulator for the first successful one, the Smiths Mk.Va autopilot >system. This system was installed in the Hawker-Siddely(Sp?) Trident >(a commercial passenger jet) and in the Short Bros. "Belfast" (an RAF >transport). It was cleared to Cat 3b, which means basically a blind >landing. [Description omitted-MFS] One of Roger Bacon's "Nephews" recounted a story about an early autoland system, probably this one. It seems that a British airline was fitting autoland to its planes during the regular maintainence cycles, resulting in a mixed fleet. One of their captains let the autoland land the plane, resulting in a rough landing. He complained to the ground crew and wrote it up. When the plane and its piece of paperwork returned, the pilot's complaint, "Autoland lands very hard", was signed off with the comment, "Aircraft not fitted with autoland". -- Mary Shafer shafer@skipper.dfrf.nasa.gov ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA "Turn to kill, not to engage." CDR Willie Driscoll -- Mary Shafer shafer@skipper.dfrf.nasa.gov ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA "Turn to kill, not to engage." CDR Willie Driscoll