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> Boeing also designed the system to rely on a single sensor — a rarity in aviation, where redundancy is common. I worked on the C-2 Greyhound aircraft in a pa

> Boeing also designed the system to rely on a single sensor — a rarity in aviation, where redundancy is common. I worked on the C-2 Greyhound aircraft in a past life. Part of an upgrade they got, only because it was an absolute requirement to fly in European airspace, was a magnetometer. The documentation on replacing and testing the new sensor, of which there was only one, was non-existent. The documentation said that the sensor could not and would never fail. While in another country one failed. In disbelief my Chief had me read out every wire in the system even though I knew it was the sensor immediately. The bird was down for weeks until we got a new one because supply didn't exist and I had to make up a suitable plan for testing the replacement on the fly. I wonder what kind of practices lead to a "this system can never fail" mentality. It should be assumed everything can and will fail.

teraflop 7y ago
This is the second time I've had occasion to post this quote here in the last week: "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair." -- Douglas Adams
inflatableDodo 7y ago
>It should be assumed everything can and will fail. And anything still seemingly working to spec over a fairly conservative cycle count has already failed. Just in ingenious ways that it hasn't yet informed you of and nobody has yet discovered. You should probably swap it out for a spare and take it apart and hit it with things till you are sure. You should probably do that now while there is still time.