AS11296 -- Hijacked?

Try this one on for size:

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.

    --Steve Bellovin,