The Preliminary Report AIR INDIA flight 171

 

The media has been analyzing the several potential causes of twin engine failures on AIR INDIA flight AI 171 on JUNE 12 2025. However, when the AIRCRAFT ACCIDENT INVESTIGATION BUREAU (AAIB) preliminary report was released recently, we find that the reason was simply that the fuel release switch of each engine had transitioned from RUN to CUTOFF position and then back to RUN position a few seconds later! The only way they could have found this information is by looking at the data of each event recorded on the Flight Data Recorder. Two FDRs were recovered from the site of the accident but only one was usable.

I managed to download a copy of the report. It mentions that the debris, including major parts of the broken plane, were spread in an area 1000 feet long and 400 feet wide. Different parts of the plane fell at different locations within this area which includes trees and five buildings. The report then mentions where each of the important parts were found. It is obvious that the plane did not fall at one place but kept moving forward.

After that, the report lists the flying experience of each pilot including how much they had flown in the last few months. The recent history of the plane is described as well including its maintenance records and the parts replaced in recent years.

After that, there is a second by second description of the flight from the time the pilots entered the cockpit till the time the plane crashed. One important point I noticed is that the co-pilot  was flying the plane while the captain was monitoring! 

Conclusions:

There are too many abbreviations in the report for even a technical layman to comprehend. A seasoned aircraft professional will get more information from the report than me.

 The pilots were aware that the fuel switches have been turned off thus cutting off the fuel to the engines. There is a conversation between the two pilots regarding this on the voice recorder as follows:

Pilot 1: Why did you cutoff?

Pilot 2: I did not do so!

The engine fuel switches transitioned to cutoff 3 seconds after takeoff.

The pilots turned the two fuel switches  back to RUN position 10 seconds after the switches had transitioned to cutoff but the engines could not recover in time to avoid the crash.

The emergency RAT got deployed immediately after liftoff and was producing hydraulic power less then 5 seconds after fuel switchess cutoff. This might indicate engine problems immediately at liftoff according to some experts.

Note: The report does not mention the names of any of the pilots.