Exclusive: How Air India Flight's Black Box Was Damaged And What Comes Next

The black box units from the wreckage of Air India Flight AI-171, which crashed 36 seconds after takeoff from Ahmedabad on June 12, killing 274 people, including 33 on the ground, have sustained damage. According to aviation sources speaking to NDTV, one of the black boxes is visibly more damaged than the other, likely due to a fall during or after the crash.

Both the Digital Flight Data Recorder (DFDR) and the Cockpit Voice Recorder (CVR), collectively referred to as the "black boxes", are currently in secure custody under the supervision of the Aircraft Accident Investigation Bureau (AAIB). 

Sources involved in the crash investigation told NDTV that a preliminary inspection shows external structural compromise, which, if not handled delicately, could risk internal data integrity.

What We Know 

1. Two black box units have been recovered - one unit is more damaged than the other.

2. A decision on what to do with the black boxes will be taken soon.

3. Options under consideration: The black boxes may be sent to a HAL facility near Lucknow, the NTSB in the United States, the Civil Aviation Authority in the United Kingdom, or to Singapore.

4. One of the black boxes has sustained damage to its outer surface. This damage occurred as a result of a fall.

5. The data on both the Digital Flight Data Recorder (DFDR) and the Cockpit Voice Recorder (CVR) is stored in binary format. This data must be converted into an engineering format, after which information will become accessible. The interpretation of this data will form the basis of the crash report.

6. It remains unclear whether a preliminary report or a final report will be issued.

7. Investigators are concerned about opening the damaged black box due to the condition of its outer casing.

8. It is possible that data from the second, undamaged unit can be retrieved within India.

9. India's aviation regulator, the Directorate General of Civil Aviation (DGCA), has stepped up randomised surveillance of relevant flights during the interim period.

10. The investigation will include analysis of debris samples and material samples from the surface of the runway.

11. Sabotage also needs to be ruled out.

12. Sources on the crash of AI-171 stated: "This is a mystery."

What Is A Black Box

The black box from the doomed Air India flight was recovered Monday, 28 hours after the crash. The 'black boxes' are actually bright orange in colour to help locate them from debris and wreckage. 

The Cockpit Voice Recorder (CVR) captures up to 25 hours of cockpit conversations, noise, radio calls with air traffic control, and audible alerts in newer aircraft models. However, AI-171 was operating a Boeing 787 delivered in 2014, prior to the 2021 mandate for 25-hour CVR storage. Therefore, the recorder likely had a two-hour recording capacity. 

The Flight Data Recorder (FDR), on the other hand, collects parameters such as altitude, airspeed, heading, vertical acceleration, and control surface movements, among others. In modern jets like the 787-8, FDRs can record thousands of parameters simultaneously and loop for over 25 hours.

The Crash And Its Aftermath

The aircraft, a Boeing 787-8 Dreamliner registered VT-ANB, lifted off at 1:39 PM on June 12 from Sardar Vallabhbhai Patel International Airport, Ahmedabad, en route to London Gatwick. Less than a minute into the flight, the pilots transmitted a distress call citing loss of thrust. Radio contact was subsequently lost.

Seconds later, the aircraft, carrying 242 passengers and crew, crashed into a residential area near Meghani Nagar, adjacent to the airport's northeast perimeter. It ignited a blaze on impact, damaging a medical college hostel and killing 33 people on the ground.

The sole survivor, seated in 11A, is a British-Indian man who was thrown clear of the wreckage.