A second-by-second timeline of how Air India’s Dreamliner flight ended in disaster

London-bound Air India flight AI171 crashed just 32 seconds after take-off from Ahmedabad on June 12, after fuel supply to both engines was cut off within a second of each other. A preliminary report found that the confused pilots were unable to restore thrust in time.

Here is a look at the sequence of events leading to the deadly crash:

  • 11:17 Hrs IST: Air India Dreamliner VT-ANB lands in Ahmedabad from New Delhi, operating as flight AI423.
  • 13:13:00 Hrs: Aircraft requests pushback and start up.
  • 13:13:13 Hrs: ATC approved pushback.
  • 13:16:59 Hrs: ATC approved start up.
  • 13:18:38 Hrs: Aircraft departs from Bay 34 at Ahmedabad’s Sardar Vallabhbhai Patel International Airport.
  • 13:19:12 Hrs: ATC queried if the aircraft required the full length of the runway. The aircraft confirmed the requirement of full length of Runway 23.
  • 13:25:15 Hrs: Aircraft requests taxi clearance, which was granted by air traffic control (ATC).
  • 13:26:00 Hrs: Aircraft taxis to Runway 23 via Taxiway R4, backtracked and lined up for take-off.
  • 13:32:03 Hrs: Aircraft transferred from ground to tower control.
  • 13:33:45 Hrs: Aircraft instructed to line up on the Runway 23.

Also read: Key points from Air India crash report released by govt a month after Ahmedabad tragedy

  • 13.37:37 Hrs: ATC clears take-off from Runway 23.
  • 13.37:37 Hrs: Takeoff roll starts.
  • 13:38:39 Hrs: Liftoff from runway.
  • 13:38:42 Hrs: Maximum speed of 180 knots reached. Immediately thereafter, both Engine 1 and Engine 2 fuel cut-off switches move from RUN to CUTOFF positions, one second apart. Engines begin to slow as fuel supply is cut off. Ram Air Turbine (RAT) deployed during the initial climb immediately after lift-off. One pilot is heard asking the other why he cut off fuel. The other answers that he has not done so.

Also read: Air India crash’s prelim report reveals ‘no defect in fuel control switch

  • 13:38:47 Hrs: Both Engine N1 and N2 drop below minimum idle speed. The RAT’s pump begins supplying hydraulic power.
  • 13:38:52 Hrs: Engine N1 fuel cut-off switch moves to RUN from CUTOFF.
  • 13:38:56 Hrs: Engine N2’s fuel cutoff switch too rest to RUN. Both engines relight, and Engine 1 begins to recover. Engine 2 is unable to reverse deceleration.
  • 13:39:05 Hrs: One of the two pilots issues a distress “MAYDAY, MAYDAY, MAYDAY” call.
  • 13:39:11 Hrs: Data recording from the aircraft stops.
  • 13:44:44 Hrs: Fire tenders leave airport premises for rescue and firefighting.

Also read: Air India crash report: 1 second to disaster, co-pilot was flying plane, Captain monitored

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