Hi Jim. The report and the coverage it is receiving (per your #msg-26862421 ) are all very interesting indeed. I'm reminded of other incidents where the origins of fatal events remain unknown for a while and are later explained, or in many cases more likely shape-fitted or rationalized, after lengthy analysis and deliberation.
A case in point came to light last month, in another area that is always vulnerable to systemic risks due to the ease with which it can and often is attacked by crackers and evil-doers, the Internet itself. As we learn in other walks of life, however, the root causes of many events are cumulative, not due to any single factor. This is what may have occurred in many aviation mishaps, or as told in the news article below:
Computer viruses may have contributed to Spanish 2008 plane crash
Aug 20, 2010
monstersandcritics.com
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On NANOG today some other views on the Spanair event were expressed, which I thought were interesting. One poster opined:
[1] The crew apparently skipped the step where they were supposed to deploy
the slats/flaps prior to takeoff.
Additionally, the warning system on the aircraft which should have alerted
the crew to the failure to extend the flaps/slats also failed to sound.
A computer virus may have had a small contribution to the failure to detect
the warning system failure in the maintenance process, but, it did not cause
the accident.
The accident is clearly the result of pilot error, specifically the failure to
properly configure the aircraft for takeoff and failure to take remedial
action upon activation of the stall warning system during the initial
climb.
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And this one, from Steven Bellovin, a respected Internet security expert, who offered:
[2] There's more to the story than that. There was a problem with a sensor -- the heater for it was running when the plane was on the ground, which it shouldn't do. The mechanic couldn't reproduce the problem; since there was no icing likely and the heater was only needed if there was icing, the pilot flipped the breaker to disable it. (The virus-infected computer was the one that should have been used to log two previous reports of that same heater problem, but no one even tried entering the reports until after the crash, so the virus wasn't at all the problem.) Because of the distractions -- the return to the gate, the co-pilot making a call to cancel dinner planes, a third person in the cockpit, the pilots indeed forgot to set the flaps -- and just breezed through the checklist item (which they did recite) rather than actually paying attention to it.
However... the accident investigators learned that in almost all previous instances, worldwide, of that heater problem, the cause was a failed relay in the "I'm on the ground" circuit. That same relay was used to activate the Takeoff Configuration Warning System -- which didn't alert the pilots to the flaps problem because the relay failed again after the plane left the gate for the second time. In other words, a crucial safety system had a single point of failure -- and that failure also contributed to the distraction that led to the pre-takeoff pilot error.
--/snip
FAC
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