Air India crash: What is a black box and how does it aid an investigation?

An Air India flight crashed near Ahmedabad's Meghaninagar on 12 June, killing 241 people; the black box, now recovered, may help investigators uncover what caused the disaster

Investigating authorities on Friday located one of the two flight recorders from the London-bound Air India Boeing 787 Dreamliner (AI171) that crashed into a densely populated neighbourhood near Meghaninagar, Ahmedabad, minutes after departing Sardar Vallabhbhai Patel International Airport. Investigators secured the rear-mounted device and will hand it over to the Directorate General of Civil Aviation (DGCA) for analysis, Reuters reported.

 

The wide-body aircraft was carrying 242 people: 169 Indians, 53 Britons, seven Portuguese citizens and one Canadian. It issued a distress signal at 1.39 pm local time and climbed only to around 625 ft before disappearing from radar. Moments after radioing “MAYDAY, MAYDAY…” to air-traffic controllers, the aircraft erupted in a fireball and crashed beyond the airport perimeter.

 

Of all those on board, only one passenger — 40-year-old Vishwash Kumar Ramesh in seat 11A — survived the impact.

 

What is a black box?

Commonly called a “black box”, an aircraft flight recorder is actually painted bright orange or yellow to aid retrieval. Developed in the early 1950s, it captures crucial data throughout a flight and is engineered to endure extreme heat, pressure, and violent impact. Australian scientist David Warren, who died in 2010, is credited with inventing the modern version that helps investigators determine why an aircraft crashes.     

 

Why is it called a black box?

Long before Warren’s breakthrough, French engineer François Hussenot experimented with optical data recorders that etched flight information onto photographic film sealed inside a light-proof container. Because no light could enter, the enclosure was dubbed a “black box”, a name that has endured even though modern units are brightly coloured.

 

What is inside a black box?

Key components include an aircraft-specific interface for recording and playback, an underwater locator beacon, a crash-survivable memory module capable of withstanding forces equivalent to 3,400 times gravity, and electronic circuitry housing data-storage chips.

 

Modern systems typically combine two separate recorders:

 

Cockpit Voice Recorder (CVR) – captures crew conversations, radio exchanges, and ambient cockpit sounds

 

Flight Data Recorder (FDR) – logs over 80 parameters including altitude, airspeed, heading, engine performance, autopilot status, pitch, and roll

 

How does a black box survive a crash?

Each recorder is encased in a hardened steel or titanium shell, insulated against fire, deep-sea pressure, and sub-zero temperatures. The unit is typically mounted near the tail of the aircraft—an area that often absorbs less impact in a crash.     

 

How does it help in an investigation?

By combining cockpit voice recordings with flight data, investigators can identify the root cause—be it mechanical failure, weather conditions, human error, or a combination.

 

Decoding usually takes 10 to 15 days, after which findings are correlated with radar data, maintenance logs, and eyewitness reports. In the case of the 12 June crash, the black box should shed light on what triggered the crew’s distress call and why communication ceased moments later.

 

Origin and evolution of the flight recorder

The concept gained traction in 1953 when Warren joined a task force investigating catastrophic mid-air explosions on the de Havilland Comet, the world’s first commercial jet. Despite initial resistance from pilots fearing surveillance, Warren developed the ARL Flight Memory Unit in 1956, capable of storing four hours of voice and instrument data.

 

Following two fatal crashes in 1963, Australia became the first country to mandate flight recorders on commercial aircraft—a standard now followed globally.

 

Crucial role in past air disasters

Several major air crash investigations have depended on black box data. The 2020 crash of Air India Express Flight 1344 in Kozhikode was traced to pilot error. In the 2015 Germanwings tragedy, when a co-pilot deliberately crashed an Airbus A320 into the French Alps, cockpit audio and data confirmed the cause.