Orcmid posts a welcome and well researched critique of the widespread software engineering legend regarding the Ariane 501 rocket launch failure. Dennis summarizes
It is simply not the case that a programming error involving a numeric conversion (some call it an overflow) was the root cause of the failure of Ariane 5 Flight 501. That's not what happened.
Understanding that the failure of Ariane flight 501 is a systems engineering failure, a failure in both process and practice, is crucial in learning to build and deploy software based systems. There are engineering lessons in this worth learning, among them lessons in design, testing, and risk assessment.
Dennis asks why software and technology people keep using the Ariane 501 story as an example of a software bug. I was speculating that the software process explanation is avoided because of a desire to reduce complex things (like, um, human process and system QA practice) to a simpler domain (software construction). (We make a similar mistake when we reduce human behavior to brain biochemistry.)
But perhaps it's more a matter of people accepting what they've heard or read. I want to write about SW bugs, what are the big ones? Oh, look, here's a story about the Ariane 5 rocket launch failure. Cool, I'll use this one. Maybe it's not a surprise that not many people are interested in the full story; they're just looking for an example, and since this one is written up in many places it must be true.
Maybe it's a bit of both, and then some. It would be good to look at this one more closely.