New Delhi, Jul 12 (PTI) London-bound Air India flight AI171 crashed 32 seconds after takeoff 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 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 cutoff 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 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 cutoff 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 PTI ANZ MR

Fuel cutoff to both engines caused rapid loss of thrust, prompting scrutiny of crew actions and emergency system response. Both engines' fuel cutoff switches moved from RUN to CUTOFF within one second after liftoff, causing rapid loss of engine speed and thrust; pilots were confused about who actuated the cutoffs and, despite returning switches to RUN and deploying the Ram Air Turbine, only one engine showed recovery. A mayday was issued and flight data recording stopped, facts that focus regulatory review on crew coordination, emergency system performance, relight procedures, and data capture during the critical climb phase.