Cockpit Voice Recorder (CVR): Recording Scope, Activation, and Survivability

022-14-01Pablo Asensio Martínez2026-03-271 min

The CVR is designed to record the audio environment of the flight deck to assist in accident investigations.

Operation and Capability

  • Recording Duration: Historically preserves the last 2 hours of recording (loop recording). Newer regulations often mandate longer durations (e.g., 25 hours) for modern aircraft.
  • Activation: Automatically energized:
    • In flight.
    • On the ground with at least one engine running.
  • Components:
    • Area Microphone: Typically located in the overhead panel to capture general cockpit sounds (switches, alerts, conversations).
    • Crashproof Recorder: Housed in the aft section (tail) for maximum survivability, fitted with an Underwater Locating Beacon (ULB).
    • Control Panel: Includes a test button and an Event Button to mark specific moments on the tape for rapid retrieval.

Recorded Information

According to CS-25 / EASA AIR OPS, the CVR must record:

  1. Radio Communications: Transmitted and received.
  2. Aural Environment: Via the Area Microphone (cockpit sounds).
  3. Interphone: Communications between flight crew members.
  4. Navigation Aids: Audio idents (Morse code) from nav radios.
  5. Public Address (PA): Announcements made by the flight crew.
  • Note: It does not typically record communications between flight attendants (inter-cabin stations) unless they call the cockpit.