CVR erasure
 

Hi, does anyone know what the little red 'erase' button on the CVR panel does actually? Looking at my FCOM, it is not addressed. Is it a farce, put there by managers to give the crew peace of mind? I push it at the gate before and after I go flying. Am I just wasting energy?

I think that you need to have a talk with your manager. Erasing aircraft records can be illegal.

Regards,

DFC

From a purely systems point of view, the ERASE feature will remove all stored recordings when the aircraft is ON GROUND and PARKING BRAKE ON.

Ths CVR was installed essentially to provide a record of cockpit sounds for use in the event of serious accident resulting in Flight Deck crew loss or injury. It was never installed as a 'spy in the sky' to monitor conversations after a normal flight, or indeed to investigate conversations after an incident when those involved are able to give their evidence afterwards. As far as I am aware, it is every pilots' personal right to erase the recording whenever he so wishes. I understand it does actually erase the loop.

The question was about CVR, not a combined unit. I am not familiar with these- for larger aeroplanes, I believe a separate CVR is used. Which type of plane uses a combined unit? Also, I cannot imagine an 'Erase' button, even on such a combined unit, will ever erase the FDR side of the unit! The 'Erase' is purely for the pilot's right to erase the CVR.

Yes, The erase button does indeed erase the entire CVR recording.

On the older tape loop type of CVR the erase was done by passing AC current though a coil of sufficient strength that the magnetic field produced covered the entire tape loop. Thus "recording" onto the loop and erasing any previous recordings. The AC used was a/c 400Hz and the check that the erase was carried out was to monitor the tape output via headphones and listen for a 400Hz hum. As previously stated the a/c has to be on the ground both engines stopped and the park brake set.

How the erase is done on newer flash memory type CVR's I'm afraid I can't answer.

I imagine erasing the CVR after an incident or accident however would be considered a serious offence