Six things to remember
There are usually two
The CVR captures cockpit audio; the FDR records aircraft parameters.
Bright colour aids searching
Orange or yellow stands out better than black among debris.
They are crash-protected
Recorder units are designed to withstand severe impact, heat and pressure.
They often sit aft
Installation favours a comparatively survivable area of the aircraft.
A beacon assists underwater
Immersion can activate an underwater locator beacon.
They support investigation
Data helps reconstruct events; it is not a live judgement of blame.
What the recorders capture
A cockpit voice recorder preserves recent flight-deck audio, including crew conversation, radio transmissions and other sounds. A flight data recorder stores selected parameters such as altitude, airspeed, heading and many system values.
The precise recording duration and parameter set depend on the aircraft and applicable requirements.
Why the colour matters
The protective recorder case may be surrounded by damaged structure, soil or underwater debris. A conspicuous finish gives search teams a better visual target.
The nickname ‘black box’ describes the idea of an opaque system whose inputs and outputs are examined—not the normal colour of the physical unit.
How the data is used
Investigators combine recorder information with wreckage, radar, weather, maintenance, operational documents and witness evidence.
A recorder rarely tells the whole story by itself. Its value comes from accurate correlation with the wider investigation.
- 01Protectcrash-survivable memory preserves recorded data
- 02Locatecolour, search evidence and beacon signals guide recovery
- 03Recoverspecialists handle and download the unit
- 04Correlateinvestigators compare data with every other source
Educational sequence only. Apply the appropriate approved guidance and see references below.
One useful question
Reflection promptWhat could an investigator infer only after comparing the voice, data and physical evidence?
Keep learning
Discover how aviation turns evidence into safer systems. Explore HKPAPA’s aviation learning programmes.
