Flight Recorders

So-called "black box", although bright in color

You might have heard words like "the search team is trying to locate the black box" in aircraft crash news. Generally the term "black box" means a device or system whose internal mechanism or operational principle are hidden from or mysterious to the user, but in the world of aviation, it refers to cockpit voice recorders (CVRs) and flight data recorders (FDRs.) Combining the functions of these two are cockpit voice and flight data recorders (CVFDRs.)

CVRs record voices and sounds in the cockpit, such as conversations between the pilot and the first officer, communications with air traffic controllers, and alarm tones suggesting some trouble.

FDRs keep track of many parameters acquired from onboard electronic systems, e.g. engine speed, altitude and airspeed, aircraft attitude, and positions of control surface actuators.

What's recorded in the CVR and FDR undergoes thorough scrutiny in case of an aircraft crash to determine the causes and contributing factors. If you watch the internationally famous TV documentary "Air Emergency (in USA) / Air Crash Investigation (in UK)" produced by Cineflix, you can see how much accident investigators from agencies like NTSB, BEA and AAIB rely on information obtained from those recorders.

Blackbox memories are stowed in highly ruggedized cases in order to protect such all-important data from crash impacts and subsequent fire.

The primary objective of investigations is not to find someone to blame, but to identify the causes and prevent recurrences of similar accidents. Flight safety has been enhanced by the accumulation of accident investigations.

FDR (left) and CVR retrieved from an aircraft fire
(both not our products, and for illustrative purposes only)
Photo credit: U.S. NTSB

Repairing a printed circuit board of an FDR