How the heck do airplanes not crash more often? To my understanding, there are millions of wires and pieces that all have to be working perfectly to keep a plane in the air, how is there not more crashes?

Question

Ive watch every mayday episode and tons of crashes are caused by like a simple screw being put back wrong after maintenance, how the hell do all these planes get good enough inspections done even fly several hours without failing and falling out of the sky?

In: 8

Answer 1

One of the main factor is that all those wires you see, are built to aviation standards. For example: The aviation standard connectors and plugs are used in professional cameras and other devices because those are that much more reliable than any other on the market. Fireproof, waterproof, tolerant to oil, heat, corrosion. You can take a plug like that, dip it in salt, put it in a oven, the. Submerge it into saline water and it will come out completely damaged but still working.

Then every important thing is doubled or tripled, so if you lose one, you have another to keep fly the thing.

Last, there are statistics, example: you build the engine computer so it will never crash or fail. Still it will do something crazy every million hour. Perfect. Then you got the engine with two computers, and two complete sets of sensors. Now, once in a million hours, one of the two will fail, actually one every 500000 hours, because you doubled the chances to make it happen by doubling the equipment. Ok. Back on statistics, every 500k hours the channel A fails. You have one chance in 500k to lose the second channel and therefore lose that engine completely. Well done, if you land within an hour, you have 1/500k chances to lose the engine. If you lose that engine,which is 1/ 500k x 500k, so 1/250000 million!!!!!! (Yes, once every 250 billion hours) you can still glide the plane to a safe spot. You may be over a mountain and die, ok, that’s gonna happen 1% of your flight time. So one hour every 25 thousand billion hours you risk to die.

That’s how they are kept safe. And consider that 99% of the aircraft systems are not vital points. Except engine and flight controls, there’s not much that can make you crash. Not without a massive warning. You basically need to have multiple failures and be stubborn enough to not declare emergency and land, keep going for a while and deliberately fly into obstacles, to actually crash.

-I’m an aircraft mechanic.

Note:I have to fix a lot of broken stuff every day, in 20 years,I saw maybe 2-3 critical parts with damage. Everything else was no consequences, just repair it to go back to safety standards.