[rtkwe]

There are two components, one is the Cockpit Voice Recorder which can be disabled because it's powered from the main system and records on a 2 hr loop that may need to be preserved if there's some incident that isn't a crash. The other is the Flight Data Recorder which isn't on a circuit breaker and records on a similar loop but is more of a crash system so they just run until there's no power on the plane for some reason.