(NBC) The NTSB lab is one of the most advanced in the world at determining what went wrong with flights like the missing Malaysian airliner.
But first it must be found.
That hinges on investigators detecting an emergency pinger that initates only after getting submerged in water.
Once that alert is detected, officials can extract a crash-protected memory module known as a black box, from the wreckage.
On that chip are audio recordings of the flight's final two hours.
Investigators download it all, listening for unusual sounds as well as verbal communication.
Also valuable is up to 25 hours of flight data.
The missing Malaysian flight is believed to be deep in the indian ocean, but these boxes are made to withstand water up to 20,000 feet.
Engineers say the deepest recovery to date was the 2009 Air France flight, meaning there's still great hope for answers, even as this search drags on.
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