Aircraft Black Boxes are electronic devices placed on aircraft to record crucial in-flight data and cockpit voices during a flight. This enables investigators to look into the moments leading up to an aircraft accident and assists them in finding out what was the cause of the accident.
Black Boxes have helped the aviation industry progress quickly after accidents in implementing new safety measures and improving aviation operations since their introduction nearly 70 years ago. When the black boxes are found after a crash, they are taken to a lab where the data is downloaded, and the information can be used by the investigators in addition to the materials of the crash site to recreate the events that may have caused the accident.
This data obtained, in most cases, can identify the cause either as a result of human error or system malfunction. Aircraft manufacturers can be made aware of any changes that need to be made to aircraft designs to ensure that other aircraft do not experience the same problems. Aircraft operators may also need to make amendments to their training or operating procedures to make flying safer for everybody.
The information contained in the Black Boxes also provides important closure to an aircraft accident which is essential to the flying public, the families of those affected, aviation personnel, and aircraft manufacturers and operators.
Aircraft Black Boxes consist of two devices – a Flight Data Recorder and a Cockpit Voice Recorder. The Flight Data Recorder is responsible for recording recent aircraft parameters while the Cockpit Voice Recorder records the sounds on the flight deck.
Flight Data Recorder
The Flight Data Recorder records recent data about a large number of aircraft parameters collected from various sensors on the aircraft. Depending on the aircraft and type of Flight Data Recorder, hundreds of parameters may be recorded such as speed, attitude, and acceleration, all engine performance characteristics such as engine temperature and fuel flow, and the position of the flight controls including the cockpit controls and the stabilizer and flap positions. In most cases, the Flight Data Recorder records the latest 25 hours of data.
Cockpit Voice Recorder
The Cockpit Voice Recorder is responsible for preserving the most recent sounds on the flight deck. The Cockpit Voice Recorder records all communications via the intercom between pilots and ATC, the public address system, other forms of verbal communications within the cockpit, and any ambient sounds in the cockpit, such as any instrument warnings sounding off that may aid in the accident investigation.
Older Cockpit Voice Recorders used to contain magnetic tapes that were designed to record the sounds involved only within the last 30 minutes before a crash. Due to advancements in technology Cockpit Voice Recorders now have storage on solid-state memory chips, and can record as long as 2 hours of cockpit sounds.
Aircraft Black Boxes are designed carefully so that they can withstand high impact and survive any type of crash. They are usually installed at the rear part of the aircraft near the tail because, in most situations, that is the least affected part in a crash.
The outer casings are made of very strong materials such as steel or titanium and the inner components are surrounded by insulating materials that protect against high temperatures and intense pressure. The black boxes can resist heat as high as 1100°C and survive in corrosive saltwater for up to 30 days.
They are painted bright orange so they can be easily found and they are also equipped with an underwater locator beacon that sends an ultrasonic signal for 30 days after impact with water improving the chances that they are located for accidents that occur over water. New regulations for locator beacons require that they contain a 90-day battery life after January 1, 2020 to prolong the life of the signal to be detected.