Flight Recorder

A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of an aircraft accident or incident. For this reason, flight recorders are required to be capable of surviving the conditions likely to be encountered in a severe aircraft accident. They are typically specified to withstand an impact of 3400 g and temperatures of over 1,000 °C (1,832 °F) (as required by EUROCAE ED-112). There are two common types of flight recorder, the flight data recorder (FDR) and the cockpit voice recorder (CVR). In some cases, the two recorders may be combined in a single FDR/CVR unit.

Since the 1970s most large civil jet transports have been additionally equipped with a "quick access recorder" (QAR). This records data on a removable storage medium. Access to the FDR and CVR is necessarily difficult because of the requirement that they survive an accident. They also require specialized equipment to read the recording. The QAR recording medium is readily removable and is designed to be read by equipment attached to a standard desktop computer. In many airlines the quick access recordings are scanned for 'events', an event being a significant deviation from normal operational parameters. This allows operational problems to be detected and eliminated before an accident or incident results.

Many modern aircraft systems are digital or digitally controlled. Very often the digital system will include Built-In Test Equipment which records information about the operation of the system. This information may also be accessed to assist with the investigation of an accident or incident.