This is a very good post, with an overview of existing ideas, which I highly recommend reading: Air India Ahmedabad accident 12th June 2025 Part 2
Excerpt:

Or we could wait two more days because certainly that would be in the flight recorder data.

I agree in principle, but it's not even a new theory, and the wait is just two days

Seconds count: That was with 10 seconds delay vs. 13 seconds for engine 2.

Time was spent with the verbal exchange, and then perhaps each pilot expected the other to put the switch back?

Anyway, the preliminary report also establishes that the aircraft had only 3-4 seconds of powered flight. (Would the gear lever be operated that early?) Everyone who saw that from the CCTV video, pat yourselves on the back.

Mayday call, dual engine failure, RAT deployment all confirmed.
TCMA was a red herring, the aircraft was firmly in air mode as the accident unfolded, and the thrust levers were at takeoff thrust the whole time.

I am going by the list in the excellent post here: Air India Ahmedabad accident 12th June 2025 Part 2

Anyway, here goes:

A. Misconfiguration or wrong takeoff data — OUT : 5 tons under MTOW, flaps 5, takeoff roll uneventful

B. Flaps retracted post-takeoff instead of gear — OUT : flaps 5 still set at crash

C. Low-altitude capture — OUT : throttle was at take-off thrust the whole time

D. Loss of both engines at or shortly after rotation — IN: confirmed to have occurred 3-4 seconds after liftoff

I. Bird strike/FOD — OUT

II.Fuel-related
1. Loss of electric fuel pumps — OUT
2. Fuel contamination — as good as OUT , but lab work is ongoing
3. Vapour lock — OUT

III. Improper maintenance — mostly OUT , switches might have been defective

IV. Large-scale electrical fault (e.g. due to water in E&E bay) — OUT . This would have been obvious from the flight recorder.

V. Shutdown of engines by TCMA — OUT . Conditions not met (not on ground, throttle not at idle)

VI. (Inadvertent) shutdown by flight crew
1. Spontaneous execution of memory items (fuel control switches OFF, then ON; deploy RAT) due to assumed engine malfunction — OUT from CVR
2. No indications whatsoever of an intentional shutdown for nefarious reasons — IN but unsupported

VII. Malfunction/mishandling of the fuel cutoff switches (most recent)
1. Wear or improper operation of the switches, so that they do not lock but can shift back into the OFF position. — IN

Read the previous post to this by 9 lives and reconsider VII.1
Senior Pilot

2. Spilled drink leading to short in the wiring — IN (barely) , 8 separate switch contacts must be affected in just the right way

If you never supported any of the theories that are now out, pat yourself on the back!

Was the RAT deployed manually?
The report says, This was 5 seconds after the fuel was cut off.

It suggests to me that the RAT deployment was initiated while the engines were still above idle and generating electrical power. Obviously one of the pilots could have done it via depressing the switch, as it's a "dual engine failure/stall" memory item (see Air India Ahmedabad accident 12th June 2025 Part 2 ) that won't hurt anything.

Is there a way for the RAT to deploy while the engines are still above idle?

nachtmusak the RAT can be deployed manually, and I believe a pilot did that here before power was lost.

What is an action slip?

There's a possible scenario we're discussing here that fits all of the available evidence. It proposes that one of the pilots operated the switches in an unconscious action called an "action slip". This is a rote action that we do without conscious thought when we're distracted: we mean to do something, and then we get our signals crossed and do something else. To learn more, search for "action slip" or "cerebellum" on this thread; I hope paulross adds the keyword to the next build of his excellent index at https://paulross.github.io/pprune-th...171/index.html .

How would this scenario play out?

We don't have enough evidence to pin down the exact sequence, so there are some assumptions here that I hope you find plausible. (And obviously it's not the only scenario that fits the evidence.) We especially do not know who did what and why, so that is all guesswork on my part. The times are taken from the preliminary report. The report places the verbal exchange among the pilots where I put it.

———

8:08:39 The 787 becomes airborne. The F/O is pilot flying (PF), with both hands on the yoke. The Captain is PNF (not flying).

8:08:42 The PNF unconsciously flips both fuel switches to CUT OFF, one after the other. This is a rote action performed after each flight, or as training captain in the simulator.
The action cuts power to the engines; they stop delivering thrust almost immediately, and the turbines start slowing down.
The 787 systems disconnect the electrical generators in advance of them failing. The right side (Captain's side) of the cockpit l oses power to most instruments. With all 4 generators offline, the RAT deploys to provide emergency power.

The PF feels the cessation of thrust. He looks at the display to see an ENGINES SHUT OFF message. He assumes the PNF shut them off, and asks him why he shut them off. This is the lowest "probe" level on the PACE assertiveness scale; see e.g. https://psychsafety.com/pace-graded-assertiveness/ or search for "probe alert" on pprune if you wish to know more. The highest level of assertiveness, E for "emergency", would have the F/O put the switches back himself immediately, but that would have required a high degree of confidence in the face of the older Captain that may have been difficult to achieve.

Since the action was unconscious, the PNF replies that he did not do that.

8:08:47 The RAT starts delivering hydraulic power, the engines decelerate past idle.

The PNF realizes that engine power is in fact cut. Eventually he checks the switches he thinks he did not touch, sees the engine 1 switch first and flips it back to RUN at 8:08:52. He then thinks to check the second switch and flips it up at 8:08:56.

The accident sequence ensues.

There's really not much the PNF can do at this point. At 8:09:05, he transmits a MAYDAY.

———

Obviously there are variations to this, for example it could have been the PF who put the fuel switches back. (In the above scenario, the PF is focused on flying—aviate!—and never turns his head to see the switches.) My goal was simply to set out a possible sequence, to see whether it feels plausible. Remember, as you see other scenarios put forth, that any issues a person could wrestle with would also be distracting. While both pilots would be very focused during the takeoff run, the moment the aircraft lifted off, the PNF could well have mentally relaxed a little, opening an opportunity for the action slip.

Thoughts?

Edit: I got the roles mixed up; in a fixed scenario, either the Captain was the PF (and may have set the switches to cutoff), or flight control changed over at the power failure.

The short answer is that we wouldn't have CVR recordings if that was possible.

Basically, the cockpit voice recorder records the pilots incriminating themselves. It was only possible to get pilots to agree to have a CVR in the cockpit by assuring them it would only be used in accident investigations. For example, on the 787's EAFR you can read out the data on a laptop connected to the onboard network, but you can't read out the CVR unless you physically access the device.

Air accident investigations must safeguard that status. Their success depends on the guarantee that the investigation results can't be used to incriminate the pilots legally. But while courts cannot subpoena the CVR recording from the accident investigation, they wouldn't have to if the board released a full recording or even just a full transcript.

In my opinion, that is why this preliminary report is vague on who said what, and what exactly was said.

The CVR must not become a constant "anything you say can and will be used against you in a court of law" in the cockpit.

I'd be happy if any lawyers in the thread (e.g. WillowRun 6-3 ) could correct or confirm.

Ugh, how could I mess this up... thank you.
That makes the scenario more complicated, where either the PIC is the PF from the get-go, or they switch control as the power fails?

The event shows that it's really imperative to relight the engines as quickly as possible.
The preliminary report says it took about 5 seconds for the engines to spool down to idle. 14 CFR \xa7 33.73 - Power or thrust response requires a jet engine to reach 95% thrust from stabilized flight idle in not over 5 seconds. So with a sufficiently quick reaction, flipping the switches back after 5 seconds, they could've been back in business by the time they actually flipped the switches back.

So it's not "flip the switches 3 seconds after liftoff and you're unrecoverable"; to be unrecoverable, there must also be sufficient time for the engines to spool down enough.

Don't ask, "why did you cut the engines", flip them back on. Go for the E in PACE.

Yes.
The ADS-B data collected by FR24 leave the aircraft at 172 knots 8 seconds 4 seconds into the outage. Vr was 155 knots per the report. The preliminary report also says it crashed at 8⁰ nose-up attitude, which was after the "flare".
Please tell me how recoverable that is, with hypothetical 95% thrust on both engines 2 6 seconds later.

edit: reviewed fr24 data and adjusted time covered; I think it did decelerate to approximately 155 knots in 10 seconds, based on -3knots/second.

Yes. The report also says that this was "consistent with the APU Auto Start logic".

The APU needs air to operate. The inlet provides that air.

Thank you for your reply! I'm aware you know more about ADS-B than I do, and I'm happy to learn.
As you know, I'm referring to the map view and data on https://www.flightradar24.com/blog/f...rom-ahmedabad/ .
That's what I thought at first, based on the time stamps.
08:08:50.87 last full ADS-B message (172 kts)
08:08:54 APU inlet door starts to open, per the report.

My problem here is that the report also says that the maximum speed was 180 knots IAS at about 08:08:42. And we have
2025-06-12T08:08:46.550875Z,8005ec,23.069138,72.625871,575
associated with 184 kts as the first ADS-B message in the sequence.
Given that the clocks of ADS-B receivers are sometimes off, I think this might actually represent the moment of maximum speed; but then the AFS-B clock would be 4 seconds fast.
And that's why I adjusted my times.

A way to cross-check would be to track the aircraft position over time from the point of rotation, or to use the new photo in the report that shows the RAT over the runway to triangulate where that was.

Yes.
Would low pressure and high temperature make IAS lower than ground speed, even with the 7 knot headwind?

Either way, if they were decelerating at approximately 3 knots per second, then they would've ended up at about 150 knots IAS, which is less than Vr.

When I look at the CCTV video, 13 seconds into the flight, the aircraft is just "over the hump" and starts descending, so that tracks.

At this point, I don't know what having the engines spool up instead of being dead weight would've done to that flight path; and how successfully the aircraft could've been recovered from that.
Maybe they had only 4 seconds to flip those switches, instead of 5 seconds?

Still, the best bet is to not ask questions, but flip these switches back ASAP, no?

That same article has been discussed before in its republished form:

Can you articulate a specific reason or grounds for thinking a camera on the flight deck can reduce the number of pilot suicides? Or is your aim merely to reduce the number of arguments about them?

It seems like a "but the children!" argument, an appeal to emotion. Same with the appeal to MH370 upthread, a camera in the cockpit would have done nothing as satellite communications were off, and the flight recorders are at the bottom of the ocean.

Camera footage from the helicopter would've helped understand what went wrong in the DCA mid-air, but that was a military craft, so...

I had a "page 1 of google results" deep look into rail, knowing that the cab cameras have helped the NTSB before, but then the external camera tends to show more interesting stuff for trains than for aircraft. In rail, camera introduction was piecewise and unregulated, often by companies who wanted to be seen doing something after an accident, and regulation came afterwards (freight trains are still not regulated).

https://www.law.cornell.edu/cfr/text/49/229.136 If I were to regulate cameras in the cockpit, I'd first try it on a smaller scale, to see if there are unforseen negative effects on safety. I'd answer the question, do pilots behave differently when there are cameras? and if so, is the change for better or worse?

Do training simulators have cameras, and is the footage used to debrief simulator sessions?

Well, many airlines already have good safety management programs using flight data for every flight, and you could use that data to look for differences: more or less unstable approaches, differences in go-around decisions, that sort of thing. I really don't know what these programs look for.

We wouldn't have the video for MH370 even if a camera was installed, so, no, it wouldn't.
We don't even know that the Ahmedabad crash was a suicide, or that there was a "premeditated plan".

Someone had posted a short clip of a simulator session where the captain did just that, and the PF then moved his hands immediately towards the switches, and the captain moved his hand back to guard them so that the PF now had to deal with the dual engine failure. I don't remember what their head movements were, and the post got lost in a hamsterwheel purge.

I've mentioned PACE before, it stands for "probe alert challenge emergency", more at https://psychsafety.com/pace-graded-assertiveness/ , or search pprune. It's a scale of assertiveness, and if there's an "authority differential", as in a junior F/O vs. a senior captain, it becomes more difficult the further you move up the scale. Hence the need for CRM.
I'd put "Why did you turn the engines off?" at the "probe" level, "What the h*ll do you think that you're doing?" at the challenge level, and reaching down to put them back would be the highest level. So I think whether someone would be capable of doing that depends on cockpit dynamics and training.

On MH370, satellite communications were off, so there wouldn't have been any "streaming".