Cockpit Voice Recorder (CVR)
The recorder capturing flight-deck audio: crew speech, radio calls, alerts and ambient sound. Its contents are legally protected.
Annex 13 restricts release of CVR audio and transcripts to the safety investigation, because crews will not speak freely on a recording that may be published. Reports quote only what is necessary, and the archive does the same.
Ambient audio matters as much as speech: engine tones, warning chimes, the sound of a stick shaker and the moment a switch is thrown all place events on a timeline.
Related terms
The crash-protected recorder that captures aircraft parameters (attitude, speeds, control positions, systems states) for at least the last 25 hours.
Crew Resource Management: how a flight deck uses all the people and information available to it. CRM breakdowns are about communication, workload and authority, not stick-and-rudder skill.
The international standard governing aircraft accident investigation. It defines who investigates, what an accident is, and that the sole objective is prevention rather than blame.