AI171 crash probe: What led to Mayday call? A timeline of Air India plane's final moments

A month after Air Indiaplane crashed in Gujarat, preliminary report by India's air accident body has been released. On June 12, Air India Boeing 787-8, flying from Ahmedabad to London Gatwick, crashed just seconds after takeoff. The aircraft was operating as Flight AI171 and carried 230 passengers, including two infants, and 10 crew members and 2 flight crew. There was only 1 fortunate survivor of the tragic plane crash.

The crash happened at 08:09 UTC (1:39 PM IST), just after the plane lifted off from Runway 23 at Ahmedabad airport. The aircraft was fully loaded with 54,200 kg of fuel and had a takeoff weight of 2,13,401 kg, which was well within the safe limits.

Timeline: What happened before the crash?

Investigators from India's Aircraft Accident Investigation Bureau (AAIB) and teams from the US, UK, Portugal and Canada are studying the events closely. Based on ATC data, voice recordings, and flight monitoring systems, here is a simple timeline of what happened:

Time (UTC) and Event

07:43:00 Aircraft requested pushback and startup.

07:43:13 ATC approved pushback.

07:46:59 ATC approved engine startup.

07:49:12 Pilot confirmed needing full runway length.

07:55:15 Aircraft got taxi clearance from ATC.

08:02:03 Transferred from ground to tower control.

08:03:45 Aircraft instructed to line up on Runway 23.

08:07:33 Cleared for takeoff (winds 240° at 6 knots).

08:07:37 Aircraft started its takeoff roll.

08:08:33 Reached takeoff decision speed (V1 – 153 knots).

08:08:35 Reached rotation speed (Vr – 155 knots).

08:08:39 Lift-off occurred.

08:08:42 Achieved max speed (180 knots). Then, both engines shut down one by one.

08:08:52 Pilots tried to restart Engine 1.

08:08:54 APU system began to start automatically.

08:08:56 Attempt made to restart Engine 2.

08:09:05 MAYDAY call made by the pilot.

08:09:11 Flight data recording stopped.

08:09:12 Aircraft crashed beyond the airport boundary.

What went wrong with the engines?

Shortly after takeoff, both Engine 1 and Engine 2 suddenly stopped working. The fuel control switches moved from RUN to CUTOFF, which cut off fuel supply. This happened within one second of each other.

The Cockpit Voice Recorder picked up a shocking exchange apparently between the pilots:

One pilot asked the other, "Why did you cutoff?" The other replied, "I didn't do it."

Moments later, the pilots tried to restart both engines. Engine 1 showed signs of recovery, but Engine 2 could not regain full power. The plane quickly lost altitude and crashed just outside the airport.

How was the aircraft earlier that day?

The same aircraft, VT-ANB, had landed in Ahmedabad at 05:47 UTC as Flight AI423 from Delhi. After landing, the crew reported a minor technical issue: a status message called 'STAB POS XDCR' in the tech log, says the AAIB report.

The on-duty engineer checked the problem, followed all procedures and cleared the plane for the next flight at 06:40 UTC.

The new flight crew, two rested pilots from Mumbai, arrived early, passed the breath analyzer test and were seen at the boarding gate by 07:05 UTC. They were fit to fly.

Was anyone else involved in the investigation?

Yes. Since the aircraft was made in the USA, the National Transportation Safety Board (NTSB) joined the investigation. Boeing (the plane’s maker), GE (engine maker), and FAA (aviation authority) also sent experts.

Officials from UK, Portugal, and Canada were informed, as citizens from those countries died in the crash.

Were there any signs of external danger?

No. The airport CCTV footage showed that the Ram Air Turbine (RAT) deployed, this happens when both engines fail. 

There were no birds, no fire and no outside obstruction. It looked like a technical failure inside the aircraft. The crash rescue team reached the site quickly. Local fire services also joined.

Experts are now carefully studying all flight data, engine systems, and cockpit recordings. The goal is to find the exact reason why both engines shut down during takeoff and how the fuel control switches moved to cutoff without pilot input.

The AAIB has started a full investigation, which will take time but aims to improve safety and prevent similar accidents.