Originally Posted by
SLFguy
I may have the wrong end of the stick but that's his point.. it wasn't lost and his question is 'why not?'.
From the report (my highlighting) :
The aircraft is equipped with 2 digital voice–data recorders (DVDRs), which are capable of recording 2 hours of cockpit audio. At the TSB’s request, the crew of C-FLWH’s subsequent flight from Toronto to Ottawa was instructed by Air Canada Operations to disconnect power to the DVDRs upon arrival in Ottawa. The flight crew was met by company maintenance staff at the gate who informed the flight crew that they would do it. The maintenance crew did not disconnect the power to the DVDRs until an hour later, and the relevant cockpit voice data was overwritten. The TSB’s review of the company maintenance control manual determined that the guidance on how to perform this procedure was unclear.
The information from the CVR
was lost. Had the CVR had more capacity then the information would not be lost. There is no reason for the CVR to be limited to 2 hours duration only.
In this case it would have been extremely useful to be able to hear what the go-around calls sounded like from the aircraft viewpoint rather than the transmitting station's viewpoint. Also the discussion in the cockpit - the "
was that for us" would have been useful.