Air India plane crash: What is a black box and what it can reveal

A London-bound Air India Boeing 787-8 Dreamliner with 242 people onboard crashed shortly after taking off from Ahmedabad airport on Thursday, prompting large-scale rescue efforts and underscoring the vital role of flight data recorders in uncovering the cause of aviation accidents.

The aircraft, flight AI-171, took off from Runway 23 at 1:39 PM IST and issued a MAYDAY call shortly after, according to the Directorate General of Civil Aviation (DGCA). The plane crashed in the Meghani Nagar area outside the airport perimeter after reaching just 625 feet altitude, exploding in a massive fireball. Captain Sumeet Sabharwal and First Officer Clive Kundar were commanding the flight carrying 232 passengers and 10 crew members en route to London Gatwick.

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As rescue teams continue searching for survivors, investigators are prioritizing the recovery of the aircraft's black box, the key to understanding what caused the aviation tragedy.

What Air India’s Boeing 787-8 black box can reveal Ahmedabad plane crash

In the Ahmedabad crash investigation, the black box will be key to determining whether the tragedy was caused by a mechanical issue, engine failure, bird strike, onboard fire, or human error. It will provide detailed insights into the crew’s MAYDAY call, any automated alerts received, and their actions to recover control in the moments after takeoff.

Ahmedabad Plane Crash: Google Earth imagery shows exact location of aircraft's take off & crash site in Meghaninagar. Watch video

With the aircraft crashing at just 625 feet, the Flight Data Recorder will capture exact data on engine performance, control surface movements, and system alerts. The Cockpit Voice Recorder may reveal if the crew followed emergency checklists, how they coordinated their response, and whether any technical issues were discussed.

Once recovered, the devices will be sent to forensic laboratories under the DGCA or Aircraft Accident Investigation Bureau, where experts will extract and decode memory modules, synchronize voice and flight data, and correlate findings with radar logs and air traffic control records.

ALSO READ: Safety Engineering expert weighs in on deadly crash, explains exactly when the problem occurred

The analysis process typically takes days to weeks depending on device damage and incident complexity. However, initial assessments are usually provided within 24 hours to guide the investigation's direction.

What is a black box?

Contrary to popular belief, aircraft "black boxes" are actually bright orange crash-resistant devices designed to survive extreme impact and fire. Every commercial aircraft carries two such recorders housed in reinforced casings built to withstand explosions, fire, water pressure, and high-speed crashes.

The Flight Data Recorder (FDR) logs critical technical parameters including altitude, speed, engine thrust, and flight path data. Modern aircraft like the crashed Boeing 787 can record thousands of parameters covering everything from cockpit command inputs to air conditioning systems. The Cockpit Voice Recorder (CVR) captures all cockpit audio - pilot conversations, radio transmissions, warning alarms, and ambient mechanical sounds that could provide crucial clues about the final moments before impact.

These recorders continuously store 25 hours of information, including data from previous flights within that timespan, which can sometimes reveal hints about mechanical failures that developed over time.

Black boxes: crucial evidence in airplane accidents

Flight recorders provide investigators with a second-by-second reconstruction of events leading up to a crash, offering the most objective account of what transpired in the cockpit and across aircraft systems. They serve as the aviation equivalent of DNA evidence in criminal cases - providing definitive, unbiased testimony when human witnesses may be unavailable.

Black box data has proved decisive in solving major aviation disasters globally, from the 2015 Germanwings crash to Malaysia Airlines incidents. In India, the 2020 Kozhikode crash investigation relied heavily on these recordings to establish pilot decisions and runway conditions during the failed landing attempt.

The devices often provide the only reliable account when there are no survivors or when physical evidence is destroyed or inconclusive. Beyond determining immediate causes, flight recorder analysis has led to industry-wide safety improvements, new training protocols, and aircraft design modifications that have prevented countless future accidents.

As search teams work to locate the black boxes amid the wreckage, these orange recorders hold the answers to understanding what caused 242 lives to be put at risk and how similar tragedies can be prevented in the future.

(With TOI inputs)

Ahmedabad plane crash: How it happened & what is a Mayday call?

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An Air India Boeing 787-8 Dreamliner flying from Ahmedabad to London’s Gatwick Airport crashed soon after takeoff. The crash happened between 1 pm and 2 pm, minutes after the flight AI171 left the airport with 242 people on board.

An Air India Boeing 787-8 Dreamliner flying from Ahmedabad to London’s Gatwick Airport crashed soon after takeoff. The crash happened between 1 pm and 2 pm, minutes after the flight AI171 left the ai..

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The plane reached about 825 feet before suddenly losing height. Videos show the aircraft flying unusually low and struggling to stay in the air before crashing and bursting into flames, likely because it had a full fuel load for the long trip.

The plane reached about 825 feet before suddenly losing height. Videos show the aircraft flying unusually low and struggling to stay in the air before crashing and bursting into flames, likely becaus..

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The flight was led by Captain Sumeet Sabharwal, an experienced pilot with 8,200 flying hours. He was assisted by First Officer Clive Kundar, who had 1,100 hours of experience. The flight had 230 passengers and 12 crew members.

The flight was led by Captain Sumeet Sabharwal, an experienced pilot with 8,200 flying hours. He was assisted by First Officer Clive Kundar, who had 1,100 hours of experience. The flight had 230 pass..

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Shortly after takeoff, the pilot sent a ‘Mayday’ distress signal but did not contact air traffic control again. A Mayday call is an emergency signal used by pilots and sailors to ask for immediate help. It comes from the French words "m'aider" meaning "help me."

Shortly after takeoff, the pilot sent a ‘Mayday’ distress signal but did not contact air traffic control again. A Mayday call is an emergency signal used by pilots and sailors to ask for immediate he..

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The plane crashed into a doctors' hostel linked to BJ Medical College in Ahmedabad. Five medical students, including four undergraduates and one postgraduate, died. Many others were injured. Photos showed food still on tables in the hostel’s dining area.

The plane crashed into a doctors' hostel linked to BJ Medical College in Ahmedabad. Five medical students, including four undergraduates and one postgraduate, died. Many others were injured. Photos s..

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The plane had a total of 242 people on board, including 169 Indians, 53 British nationals, one Canadian, and seven Portuguese nationals. The flight took off at 1:38 pm from Ahmedabad.

The plane had a total of 242 people on board, including 169 Indians, 53 British nationals, one Canadian, and seven Portuguese nationals. The flight took off at 1:38 pm from Ahmedabad.

Videos from the crash site show thick grey smoke. Over 20 ambulances were sent, and many injured people were quickly taken to nearby hospitals. Firefighters and medical teams are still working at the scene.

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