The cockpit voice recorder data on the Alaska Airlines Boeing 737 MAX 9 jet which lost a panel mid-flight on Friday was overwritten, U.S. authorities said, renewing attention on an industry call for longer in-flight recordings.
National Transportation Safety Board (NTSB) chair Jennifer Homendy said on Sunday 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 versus 25 hours in Europe for planes made after 2021.
The International Civil Aviation Organization (ICAO) has since 2016 called for 25-hour recording on planes manufactured from 2021.
“There was a lot going on, on the flight deck and on the plane. It’s a very chaotic event. The circuit breaker for the CVR (cockpit voice recorder) was not pulled. The maintenance team went out to get it, but it was right at about the two-hour mark,” Homendy said.
The NTSB has been vocal in calling for the U.S. to extend its rule to 25 hours. The U.S. Federal Aviation Administration (FAA) a month ago said it was proposing to extend to 25 hours – but only for new aircraft.
Because if you crash you only need to review the immediate events leading up to a crash. 2 hours is generally plenty. If a plane is hijacked and then crashed, you don’t need 5 or 10 hours of voice to know what caused the crash.
The point of the CVR was to find out what went wrong or what errors happened leading up to a catastrophe, not what the pilots had for breakfast 5 flights prior.
Thats not really true at leat according to aircrash investigation shows. Crew can make mistakes hours earlier that might lead to a crash or accident later. Mess up something during preflight checks and that can be the issue during later stage. Flights are long.
But with modern datastorage prices there’s really no excuse not to make it longer. With 15GB you can store 24 hours of extremely high quality audio.