Originally Posted by
Blythy
XL Airways Germany Flight 888T, quote below is from the wiki page:
Triplexing/Voting works on the assumption that a single failure is unlikely, and a failure that affects two parts simultaneously is therefore extremely unlikely. It does not take into account a single root cause failure (as in the XL airways incident) that affects two parts simultaneously.
True. It's never 100% safe. But the XL Airways crash really was a black swan event in comparison, for the holes in the cheese to line up that way:
Test flight with test pilots, intentionally stalling at 3,000' (instead of 10,000').
Two out of three AoA sensors frozen, due to water contamination from high pressure cleaning the aircraft for painting, two days previously.
Would it have been a flight with passengers, they wold not have stalled at 3,000' intentionally.