The black box .. The aircraft memory and keeper of all its secrets
16 june 2021
The black box in an aircraft is a memory that records information and data and its performance and keeps secrets of flight conditions during flight, what happens in the cockpit, conversations between crew members or with the control tower and any other sounds in the cockpit.
It is used by the authorities to investigate accidents, or disasters that befall planes in order to find out the causes and factors that led to them. It’s an orange metal box in order to be easily distinguished when searching for it.
In every aircraft, there are two boxes, not one, which are often located in the back of the aircraft, that record what happens to the aircraft throughout its operation period. The function of the first black box is to save up to more than 3000 different data, digital data and physical values that change in flight such as speed, altitude, geographical location and engine performance. This in addition to the positions of the different system switches, the status of the autopilot, the status of the automatic power supply, the position of the control surfaces and other vital data, while the second black box function is to record sounds inside the cockpit. Each box is equipped with a transmitter that works when submerged in water and sends out ultrasonic signals to help locate them and transmit these signals at a frequency of 37.5 kHz for a period of 30 days from the start of its activation until its battery is discharged. The transmission range is about 6000 meters (20,000 feet), and advanced search devices can pick up audio signals at a range of 3000 meters inside the water.
The flight data box records the last 25 operating hours of the aircraft, while the cockpit voice box records the last 3 hours of operation.
These devices are kept in very durable molds made of strong materials such as titanium alloy, surrounded by an insulating material to withstand shocks of up to 3,400 times the force of Earth's gravity, and to withstand temperatures exceeding 1100 degrees Celsius for a full hour and strong pressure equivalent to water pressure at a depth of 20,000 feet under the sea. To protect the recording pieces, they are usually wrapped with an insulating material that protects the information recorded on them and so that they are not affected by the salinity of sea water, which causes corrosion to many metals.
The Aviation Investigation Bureau (AIB) conducts civil aviation accident investigations, prepares the necessary studies to enhance the safety of civil aviation, and makes recommendations related to aviation safety and follows them up in accordance with international safety standards and practices, contained in the Thirteenth Annex of the International Civil Aviation Organization (ICAO).