> no data was available on the cockpit voice recorder because it was not retrieved within two hours - when recording restarts, erasing previous data.

> The U.S. requires cockpit voice recorders to log two hours of data

So.. what happens when a crash happens at 2:01 into a flight, you have just one minute of audio? how is that in line with the requirement to keep 2 hours of audio?

> The maintenance team went out to get it, but it was right at about the two-hour mark

> The plane's flight data recorder and cockpit voice recorder were sent to NTSB labs on Sunday to be read but no voice data was available

So as soon as that 2-hour mark is hit, the CVR secure-erases everything it recorded and starts anew? (data-recovery was not possible???) ... I feel like something is missing here...