The Cockpit Voice Recorder records any transmissions from the cockpit made through the Audio Control Panels. It also records flight deck area conversations using an area microphone.
All inputs are recorded continuously when electrical power is applied to the airplane.
As installed
The pilot can apply power to the voice recorder by placing the voice recorder switch to ON. This allows pre-flight recordings to be made. After landing, the voice recorder remains on for 5 minutes after the last engine is shutdown for post-flight recording. If the pilot desires to record longer than 5 minutes, the pilot can place the switch to ON.
Pushing the erase switch (for between 1 and 14 seconds - dependent upon equipment) erases the voice recorder (if on the ground, AC power ON and parking brake set).