One of two electronic recording devices sealed in containers, coloured orange (despite the common name black box) to make them easier to find, that are carried on all commercial aircraft. The flight data recorder (also called accident data recorder) records all instructions sent to any of the electronic systems on board. The cockpit voice recorder records everything that is said and all other sounds on the flight deck. Both recorders carry underwater radio beacons to assist their recovery. Their purpose is to aid accident investigators in determining the events preceding an aircraft accident, and the cause of the accident.