Description

Cockpit Voice Recorder (CVR) - a device used to record the audio environment in the flight deck for accident and incident investigation purposes. The CVR records and stores the audio signals of the microphones and earphones of the pilots’ headsets and of an area microphone installed in the cockpit.

Figure 1: Cockpit Voice Recorder

Regulatory Requirements

In 2015, the European Union Aviation Safety Agency (EASA) amended regulations to extend required recording duration to 25 hours. The 25-hour mandate took effect on January 1, 2021. The regulation requires any aircraft with a maximum takeoff weight of 72,000 kg (60,000 lbs) or more, manufactured about January 1, 2021, to be equipped with a CVR that has at least 25 hours of recording capacity.

In 2016, the International Civil Aviation Organisation (ICAO) adopted the same standard for aircraft manufactured after January 1, 2021. ICAO noted that the extended time was needed to cover the longest flights, to include preflight and postflight activities, delays, and the time to secure the recordings.

The U.S. Federal Aviation Administration (FAA) also plans a 25-hour CVR requirement.

ICAO amendments that took effect in 2019 state that data from CVRs and flight data recorders may be used only for safety-related purposes with appropriate safeguards, and for criminal proceedings.

History

The earliest CVRs used analog wire recording, later replaced by analog magnetic tape. Some of the tape units used two reels, with the tape automatically reversing at each end. Currently, the most widely used CVRs in commercial transportation are capable of recording 4 channels of audio data for a period of 2 hours. The previous requirement for a CVR to record for 30 minutes was found to be insufficient in many cases. In some accident investigations, significant parts of the pertinent audio data were missing as they occurred more than 30 minutes before the end of the recording (the tape capacity would result in audio information being overwritten every 30 min.)

The latest CVR use solid-state memory and digital recording techniques which make them much more resistant to shock, vibration and moisture. With the reduced power requirements of solid-state recorders, it is possible to incorporate a battery in the units, so that recording can continue until flight termination, even if the aircraft electrical system fails. Newer models of CVRs combine voice recording functions with flight data recording into a single unit. These combination recorders are sometimes referred to as Digital Voice and Data Recorders (DVDR).

Regarding the introduction of video recordings in the cockpit: the attempts of some operators to introduce on-board video recording in the flight deck have met very little success to date due to resistance from pilot professional organisations and unions.

Related Articles

• Flight Data Recorder (FDR)
• Digital Voice and Data Recorder (DVDR)

Further Reading

ICAO

• ICAO Annex 6, Operation of Aircraft

FAA

• FAA AC 20-186 'Airworthiness and Operational Approval of Cockpit Voice Recorder Systems'

NTSB

• Cockpit Voice Recorder Handbook for Aviation Accident Investigations, NTSB, December 2019

Others

• The European Organization for Civil Aviation Equipment website: http://www.eurocae.net/
• Black box flight recorders, a fact sheet issued by the Australian Transport Safety Bureau (ATSB) in 2014
• Aerospace Innovations, 10 October 2024, "25-Hour CVR Mandate is a Huge Step Forward in Flight Safety."