All large commercial airplanes and corporate jets are required to have what are commonly referred to as “black boxes.” In reality, though, black boxes are two separate pieces of bright orange equipment: a cockpit voice recorder (CVR) and a flight data recorder (FDR).
Cockpit Voice Recorders
CVRs record essential audio data in the cockpit, including what the pilot and co-pilot said as well as background noise that the plane made. Investigators can use information stored in the CVR—such as emergency warnings, the sound of the engine, and flight crew conversation—to determine why the aircraft crashed.
Located in the tail of the plane, CVRs are designed to be damage-resistant, but they aren’t foolproof. The data is also written on memory chips in case the CVR doesn’t survive impact.
Flight Data Recorders
FDRs monitor data concerning the operation of the plane: the altitude, direction, and speed of the aircraft as well as information such as whether the plane was on autopilot and how much fuel was in the tank. Using data from the FDR, investigators can construct a computer visualization of the flight to simulate when and how the crash occurred.