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by NotCamelCase 2349 days ago
> You don't go and fail some random component in the system.

I always wondered if they did that, something akin to fuzzing tests in SW. Wouldn't it be useful to detect unexpected situations that'd be catastrophic? Or the benefits from it wouldn't outweigh the cost/time loss?
3 comments
phugoid 2349 days ago
Even with a pretty good model, if you introduce new failures that were not anticipated/tested, there's a risk that the system will not behave as per the aircraft. Now you're giving "negative training" to your pilots, maybe worse than no training at all.

Also, imagine you're an airline with thousands of pilots and dozens of instructors: you're running an airline and a school at the same time. You need to build a curriculum of training and testing that will standardize your pilots. There's room for thinking outside the box but not too much.

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NotCamelCase 2348 days ago
Good point, thanks for your insights!
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gmueckl 2348 days ago
Keep in mind that this is a simulator for training the crew. This is not a hardware testbed. These are separate beasts entirely. There are all kinds of setups from component tests up to system integration testing. My understanding is that the impact of component failures is tested on these hardware integration testbeds.
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inferiorhuman 2348 days ago
I always wondered if they did that, something akin to fuzzing tests in SW.

Well Boeing certainly doesn't fuzz their software as evidenced by the major bugs in the 737 NG and 747-400's flight displays. Both had bugs that would black out all instruments under specific conditions. That got fixed fairly quickly on the 747, but apparently Boeing didn't learn their lesson with the NG.

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jaywalk 2348 days ago
The bug didn't black out all instruments, it blacked out the multi-function displays. Certainly less than ideal, but that's precisely why backup instruments exists.
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inferiorhuman 2348 days ago
The bug didn't black out all instruments, it blacked out the multi-function displays. Certainly less than ideal, but that's precisely why backup instruments exists.

The bug blacked out all six display units. What other instruments are you thinking of?

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jaywalk 2346 days ago
All critical instruments have analog backups. Altitude, speed, artificial horizon, etc.
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