From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,d923bb34ea827f56 X-Google-Attributes: gid103376,public From: digitig@cix.compulink.co.uk ("Tim Rowe") Subject: Re: Ada / Boeing 777 Date: 1996/03/16 Message-ID: #1/1 X-Deja-AN: 142956714 references: <4ia0l3INNatk@faatcrl.faa.gov> organization: Compulink Information eXchange x-news-software: Ameol newsgroups: comp.lang.ada Date: 1996-03-16T00:00:00+00:00 List-Id: ron thompson > The only "bugs", "problems", "burps", "hiccups", whatever > you wish to call them that matter in an airplane are > the ones that keep it on the ground. This is patently wrong, and dangerously so. "bugs", "problems", "burps", "hiccups" that keep an aircraft on the ground are intrinsically pretty safe. The ones that *do* matter are the ones that are likely to encourage the aircraft to *return* to the ground in an untimely and inadequately controlled manner. Commonly called a crash. As an example, there was a known fault on one of the Airbus range (which has been flying total fly-by-wire for *many* years before the 777!) that meant that when flying a heading of 00 degrees, if the pilot commanded the aircraft to turn a bit one way, the aircraft could actually turn the other way. It was turning to the correct heading, but it was going the 359 degree route, not the 1 degree route. Now, there are not many runways in the world that are close to north-south, but there are a few, and when that bug showed itself on a final approach I bet the pilots pants turned brown. The pilot recovered it safely, but it was the subject of an accident investigation, and I read about it in the published results. It turned up in comp.risks, too, as you might expect. Presumably JAA is satisfied that it's safe, but sorry, the fact that it is flying is not any such proof. AIUI the Airbus range has triplicated *diverse* systems for critical functions. The 777 has triplicated *identical* systems (I'm trusting the press for this, so it may not be gospel). digiTig (Tim Rowe)