The Black Box Explained: How Investigators Piece Together Crash Clues

On Thursday, an Ahmedabad-London Air India Boeing 787-8 Dreamliner crashed and exploded just minutes after takeoff, plunging into the Meghani Nagar area at an altitude of only 625 feet. The aircraft, carrying 232 passengers and 10 crew members, was commanded by Captain Sumeet Sabharwal and First Officer Clive Kundar, who reportedly issued a MAYDAY call shortly before the crash.

The investigators have begun efforts to recover the aircraft's black box to find the cause of death of 265 people. Aircraft "black boxes" are actually bright orange, crash-resistant devices that provide an objective account of what happened onboard. Every commercial aircraft is equipped with two such devices: the Flight Data Recorder (FDR), which logs technical parameters such as altitude, speed, engine thrust and flight path data, and the Cockpit Voice Recorder (CVR), which captures all cockpit conversations, radio transmissions and warning alarms, which have become crucial in case of aircraft accidents.

Both devices are resilient to withstand extreme fire, water pressure, and high-impact crashes. They store up to 25 hours of data which are crucial when investigating accidents where there are no survivors or physical evidence. Once recovered, these devices are sent to forensic laboratories under the Directorate General of Civil Aviation (DGCA) or Aircraft Accident Investigation Bureau (AAIB).

Experts extract and decode memory modules, synchronise FDR data with CVR recordings, and work to reconstruct the final moments of the flight to identify the cause – whether it is mechanical failure, engine malfunction, bird strike, fire, or human error. In the case of flight AI-171, one of the two black boxes, situated at the rear of the aircraft, has been recovered. Efforts are ongoing to locate the second device, typically situated in the front section of the plane.