Definition

A Digital Voice and Data Recorder (DVDR) is a device that combines both Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR) capabilities into a single unit. These recorders are installed primarily to aid investigations of accidents and incidents.

Description

DVDRs typically record 25 hours of flight data and up to 25 hours of audio. The International Civil Aviation Organisation (ICAO) and regulators such as the U.S. Federal Aviation Administration (FAA) set requirements for flight recorders. These requirements include a wide range of flight data, length of audio and data recording, and survivability of the recording units. In most installations, no single electrical failure can disable data recording.

Some units are deployable, and can be automatically jettisoned from the aircraft. These units can be useful for accident investigators when recorders would otherwise be difficult to recover, such as ocean crashes. 

Controls and indicators usually include a test button for preflight inspection, a headphone receptacle, a selector switch for testing of DVDR 1 or DVDR 2, and an erase button, which is normally disabled in flight. Operation is automatic, usually activating with the first engine start and continuing through engine shutdown. In most modern transport-category aircraft, DVDR failure is indicated by an Engine Indicating and Crew Alerting System (EICAS) message.

Further Reading

• International Civil Aviation Organistion (ICAO) Annex 6, Operation of Aircraft
• FAA Advisory Circular 20-141B, Change 1, Airworthiness and Operational Approval of Digital Flight Data Recorder Systems