Air India Flight 171 Preliminary Crash Report Is Unclear Regarding Pilot Actions

By Bjorn Fehrm

July 11, 2025, © Leeham News: India’s Aircraft Accident Investigation Bureau has issued the preliminary report of the crash of Flight 171.

The report indicates that the aircraft and flight crew were fit for flight and that the pilots were experienced, with the Captain having a total of 15,638 flight hours, including 8,596 on type, and the First Officer having 3,403 flight hours, with 1,128 on type.

The report documents the technical registration of the engine’s Fuel Cutoff switches, which transition from RUN to CUTOFF, remain at CUTOFF for 10 seconds, and then return to RUN. By then, the engine cores have slowed down below flight idle, with the engines delivering almost no thrust.

Inadequate reporting on pilot conversations and actions

The report is detailed enough on the physical events in the aircraft to understand what is happening, but it is inadequate regarding the pilots’ discussions and actions. Here is why, with excerpts from the report (which you can find here):

• After a normal rotation at 153kts with flaps in the normal 5 degress position the report states: The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter, the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off. In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.
• As per the EAFR (the intact forward data and voice flight recorder) data both engines N2 values passed below minimum idle speed, and the RAT hydraulic pump began supplying hydraulic power at about 08:08:47 UTC. As per the EAFR, the Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN at about 08:08:52 UTC. The APU Inlet Door began opening at about 08:08:54 UTC, consistent with the APU Auto Start logic. Thereafter at 08:08:56 UTC the Engine 2 fuel cutoff switch also transitions from CUTOFF to RUN. When fuel control switches are moved from CUTOFF to RUN while the aircraft is inflight, each engines full authority dual engine control (FADEC) automatically manages a relight and thrust recovery sequence of ignition and fuel introduction.
• The EGT was observed to be rising for both engines indicating relight. Engine 1’s core deceleration stopped, reversed and started to progress to recovery. Engine 2 was able to relight but could not arrest core speed deceleration and re-introduced fuel repeatedly to increase core speed acceleration and recovery.
• At about 08:09:05 UTC, one of the pilots transmitted “MAYDAY MAYDAY MAYDAY”. The ATCO enquired about the call sign. ATCO did not get any response but observed the aircraft crashing outside the airport boundary and activated the emergency response. The EAFR recording stopped at 08:09:11 UTC.

The above are the important bits from the preliminary report.

Here are my comments on the information in the report and what is not in the report that should have been there:

1. Everything is normal in the takeoff until it’s time to command and execute “GEAR UP” at about 08:08:42 UTC. Then the Fuel Cutoff switches are moved from RUN to CUTOFF. This is with a high probability done by a person as the switches are lift-guarded and these will not accidentally BOTH jump over the guard to CUTOFF. There is no discussion in the report that this could have occurred internally in the fuel system. In fact, one pilot says to the other, “ Why did you cutoff?” meaning he has either seen the action or the position of the switches.
2. The information “In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.” This is suddenly a wage and an inadequate information standard in the report. Why is the asking or responding pilot not identified (Captain as Pilot Monitoring, PM, or First Officer, Pilot Flying, PF)?
3. Why is the further conversation or actions of the pilots not described after this dialogue? Putting the switches in CUTOFF is a grave action that puts the aircraft and all people at risk. It’s improbable it’s a mistake, as there is no hand movement in this area during takeoff.
4. Why does it take 10 seconds to move engine No. 1’s switch to RUN and 14 seconds for No. 2 engine?? I would have had both in RUN within 5 seconds or less! To me, this indicates a problematic pilot interaction after the switches went to CUTOFF, for which we receive NO information.

There is a passing reference in the early part of the report about a recommendation to update the Fuel Cutoff switches to ones with an even sturdier protection against accidental movement. I place little value on this part, as the standard switches in the 787 cannot be moved without lifting the switch from its guarded position.

I interpret the inadequate reporting on pilot conversations and the remark about an even better guard mechanism being available as part of the investigation trying to conceal an ugly truth.

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