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falconcountry t1_itsfn39 wrote

Reply to comment by Akanan in TIL that flight recorders must be able to withstand an acceleration of 3400 g for 6.5 milliseconds and that this is roughly equivalent to an impact velocity of 270 knots (310 mph; 500 km/h). by IchBinKoloss

What good would it be as a data recorder if it's ejected before the crash

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Akanan t1_itsfu0d wrote

It floats, the broken aircraft don't.

If the Malaysia airline crash 370 was equipped with one of these we would have it recovered.

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Odeeum t1_itsnw0e wrote

I think they meant "what value is it if it doesn't record the actual crash data and is ejected too soon to gather any meaningful evidence?"

I could be wrong though but i think that was their intent.

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Cerebro64 t1_ittb7u3 wrote

Investigators aren't interested in impact data. They are interested in the causes of the plane leaving normal flight. Yes, impact data might be useful but that's not what the recorder is for.

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Odeeum t1_ittbnny wrote

So let's say the recorder is ejected a minute into the plane leaving normal flight...and the flight continues for another several minutes. Isn't that info highly relevant and sought after? Or are you talking seconds before impact that it's ejected? I'm curious how that mechanism works...certainly not a manual process by a terrified flight crew.

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Cerebro64 t1_ittdmlc wrote

I'm not familiar with the actual ejection systems. But what you want a FDR to capture is attitude/altitude/speed etc and systems information. So when you have some kind of catastrophic incident you can identify the failures that led up to it. Were I designing that system it would be completely automated as no flight crew is going to even be considering FDR, nor should they. Also possible that it's structurally designed to separate on impact. For example, it stays in the plane until the moment of the crash, but the force of the crash compromises the installation of the box to separate it from the aircraft. Kind of like the intentional version of high speed car crashes with unbuckled passengers that get thrown clear during the crash sequence.

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dressageishard t1_itsk7xq wrote

Still haven't found that plane.

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flakAttack510 t1_ittknpx wrote

Not as a large piece but a lot of smaller pieces have washed up on various shores around the Indian Ocean.

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