The Air India flight 171 crash on 12 June which killed 241 passengers and crew 32 seconds after take-off from Ahmedabad airport in India was related to the fuel cut-off switches according to the Air Current website.

https://theaircurrent.com/aviation-safety/ai171-investigation-fuel-control-switches/

The WSJ and Reuters are reporting the same sources and findings from a preliminary report as well. According to these reports, both fuel cut-off switches were found in the CUT position, which should be an impossible scenario if the crew had been following SOP.

https://www.youtube.com/watch?v=MD64uYK926o

Even if one engine had failed on rotation as the plane took off, SOP dictates that the crew would continue to fly the plane up to a pre-determined safe ‘one engine out' altitude before attempting to run any check-lists, switching fuel feeds on and off, or attempting any engine restart procedures. The switches themselves have physical guards, and spring-loaded detentes to prevent accidental mis-operation.

The 15 page AAIB preliminary report is now available and confirms that the data and CVR systems show that the fuel cutoff switches for both engines were toggled to the CUT position barely 4 seconds after take-off:

https://aaib.gov.in/What's%20New%20Assets/Preliminary%20Report%20VT-ANB.pdf

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.

The data then indicates that both switches were toggled back on, which relit both engines, but the engines were unable to develop enough thrust in time to prevent the crash.

Here's picture of the fuel switch layout:

Its being very mysterious now,i think the final report will reveal everything.

It suggests to me the one who responded was lying about not turning them off. In the absence of poltergeists, I can't see any other explanation.

1 hour ago, StringJunky said:

It suggests to me the one who responded was lying about not turning them off. In the absence of poltergeists, I can't see any other explanation.

I wonder about pilot fatigue. Air India has been in the news recently for failing to comply with guidelines for max hours and rest periods. Or maybe he or she just wasn’t thinking, for some other reason, preoccupied with a personal problem or something. A bit like someone absent-mindedly putting their house keys in the fridge.

Edited July 13Jul 13 by exchemist

36 minutes ago, exchemist said:

I wonder about pilot fatigue. Air India has been in the news recently for failing to comply with guidelines for max hours and rest periods. Or maybe he or she just wasn’t thinking, for some other reason, preoccupied with a personal problem or something. A bit like someone absent-mindedly putting their house keys in the fridge.

If they are really knackered, I suppose that could happen. I think adding to flight protocol a rule that touching critical functions requires an explicit verbal declaration of ones intent and subsequent consent of the co-pilot before proceeding. Saying this, I think they do already before and on take off. I saw a YT video of two airline pilots verbally going through the motions of taking off prior to proceeding with an action.

13 minutes ago, StringJunky said:

If they are really knackered, I suppose that could happen. I think adding to flight protocol a rule that touching critical functions requires an explicit verbal declaration of ones intent and subsequent consent of the co-pilot before proceeding. Saying this, I think they do already before and on take off. I saw a YT video of two airline pilots verbally going through the motions of taking off prior to proceeding with an action.

Since I wrote that I've seen a bit more of the report, which claims both pilots were properly rested. However, there was a comment from an experienced pilot who said that turning these fuel switches on and off is such a routine action that it becomes delegated to "muscle memory". If so, a keys-in-the-fridge scenario could well be the explanation.

We do get these mystifying cases of human error from time to time. As far as I recall, nobody ever found out why the driver of the Moorgate Tube train accelerated into that blind tunnel wall.

One interesting detail mentioned in the report is that the investigation team had to rely on a ‘Golden Chassis’ device to read out the data stored on a heavily damaged ‘black box’.

https://www.ndtvprofit.com/nation/ai-plane-crash-us-golden-chassis-helped-aaib-download-raw-data-from-black-box

The Boeing 787-8 carries two Enhanced Airborne Flight Recorders (EAFR) each of which records both the flight data inputs, and the audio from the cockpit voice recorder (CVR) system. One unit is mounted in an equipment bay at the front of the plane, and the other is in the aft section.

Both EAFR units were recovered, but both were found to be seriously damaged. The aft unit in particular was completely unreadable owing to severe impact and fire damage. The AAIB team managed to download the data from the forward unit by breaking open the crash protection module (CPM) and transplanting the memory card into an identical ‘Golden Chassis’ unit

The crash survivable- memory unit (CSMU) is the most critical component as it stores the valuable flight data. If necessary, specialists transfer the data chips into a golden chassis, a specialized device that prevents further data loss while allowing a safe download. “We have in the laboratory every western-made flight recorder, ordered from the manufacturers with one simple modification: a modification that turns off any further writing of data.

https://uniforce-sog.org/index.php/flight-recorder-analysis/

i.e. a write-protected data-recovery jig.

2 hours ago, exchemist said:

Since I wrote that I've seen a bit more of the report, which claims both pilots were properly rested. However, there was a comment from an experienced pilot who said that turning these fuel switches on and off is such a routine action that it becomes delegated to "muscle memory". If so, a keys-in-the-fridge scenario could well be the explanation.

We do get these mystifying cases of human error from time to time. As far as I recall, nobody ever found out why the driver of the Moorgate Tube train accelerated into that blind tunnel wall

Right. Yeah, if something is muscle memorized, the conscious brain is likely not engaged to that task. That would explain having no memory.

Edited July 13Jul 13 by StringJunky

Still mystifying. If muscle memory kicks in, it usually (from my experience and others I've talked with) repeats an action done at the start of a routine. A common example is a motorist with the hand operated parking brake. Before driving, you release the PB. If muscle memory kicks in, you tend to repeat the releasing motion (as if you hadn't remembered already doing that). You don't reengage the brake. I would think turning on fuel lines would be similar - you would absently repeat the "run" motion and realize from kinesthetic feedback you'd already done so and administer a forehead slap. Not saying the muscle memory theory is wrong, just that it is a truly bizarre anomaly if that's what happened. Toggling up and down are distinct moves. Plus, these are two separate switches so one would have to make this bizarre error twice, wouldn't one?

To use my earlier example, it's a bit like driving down the street in a car with two parking brakes and reëngaging them both.

1 hour ago, TheVat said:

Still mystifying. If muscle memory kicks in, it usually (from my experience and others I've talked with) repeats an action done at the start of a routine. A common example is a motorist with the hand operated parking brake. Before driving, you release the PB. If muscle memory kicks in, you tend to repeat the releasing motion (as if you hadn't remembered already doing that). You don't reengage the brake. I would think turning on fuel lines would be similar - you would absently repeat the "run" motion and realize from kinesthetic feedback you'd already done so and administer a forehead slap. Not saying the muscle memory theory is wrong, just that it is a truly bizarre anomaly if that's what happened. Toggling up and down are distinct moves. Plus, these are two separate switches so one would have to make this bizarre error twice, wouldn't one?

To use my earlier example, it's a bit like driving down the street in a car with two parking brakes and reëngaging them both.

If there is an undercarriage retraction switch, say, that is similar, one might perhaps engage the wrong muscle memory if distracted. But we shall have to see what further analysis reveals, I suppose.

If someone had accidentally pressed the button there would not have been enough time to understand the problem and turn it off and stop the fall. We are talking about seconds after the plane took off.

8 minutes ago, Sensei said:

If someone had accidentally pressed the button there would not have been enough time to understand the problem and turn it off and stop the fall. We are talking about seconds after the plane took off.

According to the report, the error was recognised and both engines re-lit before impact, though neither was able to spool up and develop enough thrust in time.

45 minutes ago, Sensei said:

It usually takes 2 to 5 minutes to restart the engine.

Google AI:

"Starting a Boeing aircraft engine typically takes about 2 to 5 minutes, but the time can vary depending on the specific engine type and conditions. Older models like the 737NG can start relatively quickly (around 45 seconds per engine), while newer models like the 737 MAX and A320neo can take longer, potentially 2 to 4 extra minutes per engine due to procedures like bowed rotor motoring (...)"

When your engines don't work the first thing you think about is a reboot. The problem is time. And the real structural problem is that people don't think where they create these airports. The entire strip behind (and before) each airport should be a highway on which you could make emergency landings..

Airports are made on the rump, then the land is sold and developed thickly, and then nothing can be done about it anymore after years of human folly..

..a few kilometers before/behind each lane should be a highway, after which, in case of problems, you would land..

I suggest you read the report, then, or the synopses of it that have appeared in the media:https://www.bbc.co.uk/news/articles/cx2gy78gpnqo

QUOTE

The switches were returned to their normal inflight position, triggering automatic engine relight. At the time of the crash, one engine was regaining thrust while the other had relit but had not yet recovered power.

UNQUOTE

Who knows more about this subject: the people who wrote the report or you?

2 hours ago, exchemist said:

If there is an undercarriage retraction switch, say, that is similar, one might perhaps engage the wrong muscle memory if distracted. But we shall have to see what further analysis reveals, I suppose.

There is a useful YT video by blancolirio (Juan Browne) which includes a sequence from another video by ‘Just Planes’ showing a normal Boeing 787-8 Dreamliner take-off as seen by a cockpit camera mounted directly behind the pilots. The clip shows the First Officer co-pilot flying the plane in the RH seat, with the Chief Officer monitoring the take-off from the the LH seat - which matches the scenario of the AI-171 incident.

The clip begins at 6:50 elapsed in the YT video, and you can see the PIC (pilot in charge) reaching for the switch to retract the landing gear at 9:04 once a positive climb rate has been confirmed by the FO. That switch is nowhere near the fuel cut-off switches below the throttle levers.

https://www.youtube.com/watch?v=wA_UZeHZwSw

@toucana Thank you for your constructive input, just for a change..

Edited July 13Jul 13 by Sensei

1 hour ago, toucana said:

There is a useful YT video by blancolirio (Juan Browne) which includes a sequence from another video by ‘Just Planes’ showing a normal Boeing 787-8 Dreamliner take-off as seen by a cockpit camera mounted directly behind the pilots. The clip shows the First Officer co-pilot flying the plane in the RH seat, with the Chief Officer monitoring the take-off from the the LH seat - which matches the scenario of the AI-171 incident.

The clip begins at 6:50 elapsed in the YT video, and you can see the PIC (pilot in charge) reaching for the switch to retract the landing gear at 9:04 once a positive climb rate has been confirmed by the FO. That switch is nowhere near the fuel cut-off switches below the throttle levers.

https://www.youtube.com/watch?v=wA_UZeHZwSw

OK so not that then.

Here's a bit from a Telegraph article that may eventually eliminate the pilots as the cause:

"Indian media, however, reported that investigators were examining potential electrical and digital faults that could have triggered “uncommanded” actions.

“The probe will ascertain the possibility of an ‘uncommanded transition’ of the fuel control switches to the cut-off mode seconds after the lift-off,” an official aware of the investigation was reported to have said.

Just hours before take-off, a pilot flying the same aircraft from Delhi to Ahmedabad noted in the technical log a “stabiliser position transducer defect”, the newspaper said.

The stabiliser position transducer is a sensor that controls the up and down movement of the aircraft’s nose, and transmits the data to flight control systems. The official said the malfunction was checked and the engineer did the troubleshooting.

“The malfunction is a critical issue as it can trigger incorrect responses in flight control, including unintended fuel cut-off signal,” the official was quoted as saying.

There had been at least two more similar incidents on the aircraft in the weeks before the crash, the newspaper said."

Edited July 17Jul 17 by StringJunky

2 hours ago, StringJunky said:

The malfunction is a critical issue as it can trigger incorrect responses in flight control, including unintended fuel cut-off signal,” the official was quoted as saying.

Yes it's hard to imagine an issue of avionics more critical than unwanted fuel cutoff. Boeing is not having a great decade. I wonder if jet design might have to go back to a mechanical linkage for control of fuel lines. That would take some doing!

(I am relieved to learn that investigators are looking elsewhere than pilots turning off the fuel to both engines, flipping two separate switches, due to a misfire of "muscle memory." )

2 minutes ago, TheVat said:

Yes it's hard to imagine an issue of avionics more critical than unwanted fuel cutoff. Boeing is not having a great decade. I wonder if jet design might have to go back to a mechanical linkage for control of fuel lines. That would take some doing!

(I am relieved to learn that investigators are looking elsewhere than pilots turning off the fuel to both engines, flipping two separate switches, due to a misfire of "muscle memory." )

So am I. At least they are doing their best to eliminate all possibilities before blaming the pilots.

Edited July 17Jul 17 by StringJunky

New reporting in the WSJ suggests that investigators now believe it was the Captain who turned the fuel switches off, while the junior First Officer was flying the plane in the RH seat on takeoff.

https://www.wsj.com/world/asia/air-india-crash-senior-pilot-eab72db5?mod=hp_lista_pos4

The report is apparently based on sources within the US federal  NTSB (National Transportation Safety Board) agency.

🧐 Hello plane-folk ! After exhaustive forensic and psychological examination , the involved investigative authorities appear to be leaning towards pilot malfeasance as the cause .

It appears that the Pilot-Monitoring had his right-hand in proper position behind the throttles , then dropped it down and toggled both switches to the off position .

The above apparently caused the Pilot-Flying to question/argue with him , causing the P-M to belatedly undo his actions , but it was too late .

29 minutes ago, Professor-M said:

🧐 Hello plane-folk ! After exhaustive forensic and psychological examination , the involved investigative authorities appear to be leaning towards pilot malfeasance as the cause .

It appears that the Pilot-Monitoring had his right-hand in proper position behind the throttles , then dropped it down and toggled both switches to the off position .

The above apparently caused the Pilot-Flying to question/argue with him , causing the P-M to belatedly undo his actions , but it was too late .

Such claims should come with a link to their source. As, you might note, others have repeatedly done in the thread.

Mr. Swansont ,

Currently my ability to introduce Links and Photos is compromised . The inability to transfer in photos of Links is actually the most crippling , especially for voluminous ones .

I need some pointers on how to best access these functions . 🤔

*Reference Video below : -

^ Air India 171 : New Report Data Reveals RAT Deploy Timestamp

^ youtube.com/watch?v=SgAFZNkkNKw&si=TKu8scOb-j6377Hb

Edited July 27Jul 27 by Professor-M