What Causes Commercial Jets To Crash
Black boxes
Following a jetliner accident, the media is quick to report on the search for the "black boxes," or the airplane's flight data recorder and cockpit voice recorder. Together, these two units tell the story of the flight. Actually painted bright orange, these recorders are equipped with "pingers" or radio and acoustic beacons that aid in their retrieval. These two recorders are critical for providing clues as to why an airplane went down. They enhance overall flight safety by helping airlines, manufacturers and regulators prevent similar losses in the future.
- Flight data recorder: A flight data recorder captures a flight's history. It records "air data" such as the airplane's speed, heading, altitude, rate of climb or descent, accelerations, and decelerations. The plane's systems and functions are also recorded, along with information about engine thrust and the position of control surfaces (flaps and rudder). Flight crew and autopilot control actions are also recorded. Older flight data recorders stored information on metallic foil and recorded relatively few things. Newer units record hundreds of "parameters" and store this information on microchips.
- Cockpit voice recorder: A cockpit voice recorder picks up all cockpit noises, radio communications, flight crew announcements, and flight crew conversations.
In their quest for answers, investigators study both the flight data recorder and the cockpit voice recorder to piece together the details of the accident. The cockpit video camera may soon be used to add a visual component to these diagnostic recordings.