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=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ac9405996d0dcb7f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news2.google.com!proxad.net!usenet-fr.net!enst.fr!melchior!cuivre.fr.eu.org!melchior.frmug.org!not-for-mail From: "Alexander E. Kopilovich" Newsgroups: comp.lang.ada Subject: Re: Would You Fly an Airplane with a Linux-Based Control System? Date: Sun, 5 Dec 2004 04:29:36 +0300 (MSK) Organization: Cuivre, Argent, Or Message-ID: References: NNTP-Posting-Host: lovelace.ada-france.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: melchior.cuivre.fr.eu.org 1102210141 63438 212.85.156.195 (5 Dec 2004 01:29:01 GMT) X-Complaints-To: usenet@melchior.cuivre.fr.eu.org NNTP-Posting-Date: Sun, 5 Dec 2004 01:29:01 +0000 (UTC) To: comp.lang.ada@ada-france.org Return-Path: In-Reply-To: ; from Enrique Laso Leon at Sat, 4 Dec 2004 19:58:07 +0100 X-Mailer: Mail/@ [v2.45 MSDOS] X-Virus-Scanned: by amavisd-new-20030616-p10 (Debian) at ada-france.org X-BeenThere: comp.lang.ada@ada-france.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Gateway to the comp.lang.ada Usenet newsgroup" List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , X-Original-Content-Transfer-Encoding: 7bit Xref: g2news1.google.com comp.lang.ada:6765 Date: 2004-12-05T04:29:36+03:00 Enrique Laso Leon wrote: > The problem here was that the people who designed the IRS for Ariane 4 used >an asumption on its trajectory in order to avoid a check that would have >made the software tolerant to Ariane 5 trajectory (but why ?). Yes, why?... Why what? Why they avoid that check or why they didn't think about possible unhappy consequences for Ariane 5, Ariane 6, etc., assuming all kinds of misuse attempts? Or perhaps they should design that IRS as truly universal, suitable not for rockets only, but for all future devices that need a functionality of this sort? > This is at >best ignoring a basic rule of engineering : expect your design to be used in >a way you did not think about, because this is just what is going to happen. To which limits? Are there any limits or not? Are those limits the same for all kinds of products - commodities, standard parts, unique systems (rockets, for example)? Who is in charge for setting those limits? Is there any basic rule for judging from outside whether those limits were set incorrectly when they were exceeded and disaster happened? Alexander Kopilovich aek@vib.usr.pu.ru Saint-Petersburg Russia