Black boxes have been used since the earliest days of aviation. The Wright brothers carried the first flight recorder aloft on one of their initial flights. This crude device registered limited flight data such as duration, speed, and number of engine revolutions. Another early aviation pioneer, Charles Lindbergh, used a somewhat more sophisticated version consisting of a barograph, which marked ink on paper wrapped around a rotating drum. The entire device was contained in a small wooden box the size of an index cardholder. Unfortunately, these early prototypes were not sturdily constructed and could not survive a crash.
The Crash Investigation Officers rely on a device known as "The Black Box". These devices are used to record the end moments of the flight of an aircraft. This information helps in giving the investigation party some clue of what was behind the disaster. The Black Box is broken down into two different pieces of equipment. The first piece of equipment is the flight data recorder (FDR), also known as an ADR or accident data recorder. The FDR/ADR is an electronic device employed to record any instructions sent to any between electronic systems on an aircraft. The FDR/ADR is used to record specific aircraft performance parameters like engine performance and control surface settings. The second type of flight recorder is the cockpit voice recorder (CVR), which records conversation in the cockpit, radio communications between the cockpit crew including conversations with air traffic control personnel, as well as ambient sounds. In some cases, both functions have been combined into a single unit vice two units.
Due to their importance in investigating accidents, these ICAO regulated devices are carefully engineered and stoutly constructed with titanium to withstand the force of a high-speed impact and the heat of an intense fire. Contrary to the "black box" reference, the exterior of the FDR is coated with heat-resistant bright orange paint for high visibility in wreckage. The unit is usually mounted in the aircraft's empennage commonly known as the tail section, which is chosen due to the survivability factor of the location during a severe crash. Following an accident, the recovery of the FDR/CVR is the number one priority item for the investigating body to find. The reason for this is because that an analysis of the recorded parameters will often detect and identify causes or contributing factors to an accident.