Originally Posted by
Piltdown Man
Airbubba - The CVR on most Embraer EJets runs for a perpetual two hours the moment the aircraft is powered up. The vital stuff would have been obliterated before it even departed. Also, don't get me wrong, but if my goose was cooking I'd be sorely tempted to press the erase button before I left the aircraft.
Thanks. I think it works that way on some modern Boeings as well but I didn't realize it until quite recently. I believe that erase button is a regulatory legacy of ALPA's begrudging acceptance of the CVR's half a century ago.
And, since the current nonvolatile CVR recoding technology seems to be a form of flash memory, is the erase really secure or can some of the audio later be forensically recovered? I seem to recall reading an NTSB report with an earlier CVR that commented that technology existed to recover audio that had been overwritten up to seven times.
The NTSB has long advocated routine auditing of the CVR to confirm compliance with standard operating procedures. From discussions here and elsewhere I think some non-U.S. carriers have already been doing this for many years.
ALPA understandably is less than enthusiastic about this idea:
ALPA Voices Adamant Opposition to Cockpit Voice Recorder Monitoring
ALPA Members Can Help
March 2, 2010 - ALPA this week voiced its intense opposition to proposals to monitor cockpit voice recorders to the traveling public, federal regulators, and Capitol Hill.
Alpa > Organizing >
The operating pilots in the ORD incident are Teamsters, not ALPA, but if the CVR ends up in court in an action with the pilots as respondents it seems to me that the claimed privacy protection of the recorded cockpit communications will be eroded for us all.