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Date: Fri, 27 Jun 2003 12:31:52 -0400
From: Hyman Rosen <hyrosen@mail.com>
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Subject: Re: Boeing and Dreamliner
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Date: 2003-06-27T12:31:52-04:00
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Richard Riehle wrote:
> The Ada code that caused a problem in Ariane 5 was perfectly
> good code reused from Ariane 4.

It was not perfectly good code. It contained an implementation
shortcut that was specific to the possible trajectories of the
Ariane 4, but the code containing this shortcut had no comment
as to why this was OK, nor was this documented in the description
of the SRI software.

While people here are focussed on the fact that the trajectory
specs were not made part of the specs of the Ariane 5 SRI, the
actual problem was that the Ariane 4 SRI programmers did not
indicate that the trajectory specs for the Ariane 4 actually
impacted the implementation of the SRI code.