Air India flight to London Gatwick crashed in Ahmedabad - 12 June 2025

[whole diary]

[IndustryInsider]

Whilst the following is speculation, it's informed by reading/watching analysis from professionals in the airline industry.

Bird strikes now seem less likely given that there has been an official announcement that no bird carcass debris was found on the runway or immediately beyond it.

Dual engine 'failure' still seems the most likely cause, although this 'failure' now seems unlikely to have been due to external factors. Nearly all informed professionals have agreed that the Ram Air Turbine (RAT^▸ (Ram Air Turbine)) deployed. This would happen automatically in three scenarios at the stage of flight of this aircraft:

- If it detected complete failure of flight critical electrical systems.
- Very low/no pressure in all three of the hydraulic systems that are on the 787.
- Engine thrust on both engines dropping below idle.

For one (or more) of those to happen at this stage of flight, without an external factor, is almost unheard of.

Now, I don't know if the pilots could instigate one or more of those failures accidentally. Pilot error is a leading cause of air accidents. But it's usually errors in responding to something the aircraft is doing or telling them.

From the flight dynamics there's no evidence that just one engine 'failed'. There would be almost immediate asymmetric thrust causing the plane to yaw. So, it's unlikely the pilots shut down the wrong engine.

There's been analysis of the landing gear position. That suggest that 'gear up' was selected but the process didn't complete. The trucks had swivelled forward, as they are meant to do before they are stowed. Not completing their retraction suggests loss of hydraulic power.

The surviving passenger mentioned lights flickering before the crash. Eye witness accounts are notoriously unreliable, particularly from someone who has survived a traumatic event. But if there was light flickering that suggest an electrical issue.

So with possible hydraulic issues and potential electrical issues that begins to point to a loss of power generation for those systems. That can only mean both engines 'failed' almost simultaneously. As I said, almost unheard of. Even with US Airways Flight 1549 the engines didn't spool down in tandem. One of their engines briefly spooled back up.

Pictures of the post crash wreckage also appear to show the Auxiliary Power Unit (APU) door partially open. This could of course be post crash damage, but if the APU was being deployed this further suggest a complete loss of power from the engines. The RAT provides power for critical systems. The APU provides electrical power for more systems to come back online. On this flight though there wouldn't have been enough time for the APU to fully start up.

It seems that something in this plane decided to shut down both engines. There has been a lot of technical explanations on specialist forums, and from professionals on social media, that explain how this might have happened. It wouldn't surprise me to hear in the preliminary report that a system controlling engine function or fuel delivery designed to do one thing, erroneously did another. Or activated when it shouldn't have.

I am looking forward to reading the preliminary and full investigation reports when the are released to find out what happened. 

Don't see the point in speculatution, informed or otherwise.

[JayMac]

Many of the professionals who are giving informed opinion are pilots themselves. I detect a mounting concern that this was something the aircraft did that was totally unpredicted and unexpected.

I fully understand and appreciate why they give their professional opinion. Informed speculation is far, far better than sensationalist journalism or social media conspiracies.

I highly recommend watching YouTuber Mentour Pilot give his take on this tragic incident. Petter Hörnfeldt is a very experienced captain, with over 10,000 hours experience flying Boeing 737s. He's also a type rating instructor/examiner and a line training captain. He knows his stuff. He also has an encylopaedic knowledge of air accidents.

https://youtu.be/Rjc5M6JyriY?si=9OABjoJwSJPLgLDf

[ChrisB]

Blimey - eight whole minutes of total waffle.....is it all like that with just their opinions in the last few minutes?

[JayMac]

It seems that something in this plane decided to shut down both engines. <snip>

It wouldn't surprise me to hear in the preliminary report that a system controlling engine function or fuel delivery designed to do one thing, erroneously did another. Or activated when it shouldn't have.

The highlighted word in the first sentence can of course be replaced by 'someone'. And the highlighted final sentence could of course also read, "Or was activated by someone when it shouldn't have been.'

There has been renewed informed speculation today from a respected air industry publication. The Air Current is quoting several sources close to the investigation who say that the investigation is narrowing in on the fuel cut-off switches. These are two switches located immediately below the thrust levers on a 787. They do what they say. Cut off fuel to the engines. In the vast majority of uses these switches are turned on during the pre-flight and/or engine start checklist. And turned off during the shutdown procedure, usually after being parked at the gate. There are other procedures where these switches may be toggled, as part of an in flight emergency checklist, such as an engine failure/fire.

Whilst these switches are near the thrust levers they can't be accidentally moved during a critical stage of flight. When in the 'Run' position they require a deliberate two stage action - pull the switch up then toggle it to 'Cut-off'. And obviously, to do both then the action has to be repeated. Pilots are taught not to toggle both switches (one with each hand) simultaneously as this can become an undesirable muscle memory action.

So, if the investigators are focusing on these switches then there's the possibility the fuel supply to both engines was cut off by a deliberate or unintended action. Or one engine failed and the other was shut down in error. That is possible, although asymmetric thrust would likely have been evident, unless the shutdown was very quick or the aircraft/pilots reacted very quickly to any asymmetry. That's not to suggest pilot actions were malicious. It could've been a mistake, or it could have been in response to some other issue that caused both engines to 'fail'. With one of the first items on the 'dual engine failure' checklist being to to move the fuel switches to 'cut off' in preparation for a relight sequence, the pilots may have been actioning that.

Another reason to speculate that this incident was the result of a deliberate or unintended human action is the lack of any air safety/airworthiness bulletins. Had the investigators found anything that pointed to a system malfunction, from the FDR^▸ (Forest of Dean Railway, heritage line - or possibly, depending on context, Flight Data Recorder, an item of safety equipment installed on aircraft, in case of problems: it forms part of the so-called 'black box' - which is actually bright orange, to make it easier to recover, in case of need), or from debris examination, then there would have been bulletins issued to all operators of the aircraft and engine type.

An interim report is expected by this Friday, 11th July. Under ICAO^▸ (International Civil Aviation Organisation) rules, states in charge of an investigation must report to ICAO within 30 days. There is however no requirement for that interim report to released to the public.

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

[ChrisB]

A Mayday was issued by the pilots. The above doesn’t really gel with that?

[JayMac]

A Mayday was issued by the pilots. The above doesn’t really gel with that?

Depends on the timing of that mayday transmission. Aviate, navigate, communicate. It may have been the last action they took knowing they couldn't recover from their predicament.

[TaplowGreen]

Pleased to see that speculation is still being avoided!

[Clan Line]

I believe that it is a requirement that the investigating authority issues an initial report within 30 days of the accident. Of course, the content of that report will only be what they are able/willing to release -  but often, what they don't say tells you far more than what they do say.

[JayMac]

Pleased to see that speculation is still being avoided!

Merely commenting on the informed opinions being reported. And always seeking more than one take - in this instance, watching what experienced pilots have to say about this latest news. This forum is not a speculation free bubble. If it's good enough for Reuters to report on I see no reason why we can't do the same here. I have however not bothered to comment on some of the fantastical crap being spouted by some on social media. Their 'theories' aren't worthy of repeating.

[TonyK]

I believe that it is a requirement that the investigating authority issues an initial report within 30 days of the accident. Of course, the content of that report will only be what they are able/willing to release -  but often, what they don't say tells you far more than what they do say.

I think that is right, although if anything is identified earlier that could happen again in the same same type of aircraft, that is usually put out at once with guidance to operators, crew, and manufacturers as appropriate. Air accident investigations aren't about blame, but are intended to make aviation safer, so anything important will be released without waiting for the full outcome. The absence of such a release suggests the absence of an identified issue with either the aircraft type or crew training, but only suggests.

The fuel switch hypothesis has been mentioned. For anyone wondering, they are the two round knobs with a sort of red cross on them in the picture, immediately below the thrust levers. You'll see that there are raised flanges either side (on Airbus 330 aircraft there is one in the middle too) to prevent accidental brushing against them from moving the switches. As JayMac says, they have to be lifted before moving them. Air accident investigators will always look at the position of all controls as they start to rebuild the craft from the wreckage, but IF the switches are off, that doesn't solve the matter. My engine failure on take-off checklist for a Piper Cherokee says to switch off the fuel supply if there is time, and the same may be true for a 787. I have no idea.



Flaps have been mentioned in the past. Some flap is always deployed with heavy aircraft taking off to add lift and so be able to depart with less runway and at a lower airspeed than without. It saves fuel as a bonus, despite the added drag. I have seen video of a pilot in a 787 simulator taking off, heavily laden, without flaps, done following this awful accident. It does manage to get airborne, but alarms and warnings are sounding and lights flashing from the moment the thrust levers are pushed forward. As with the other pointers, I shall await the outcome of the inquiry. There is seldom, if ever, a single cause of an air accident.

[Clan Line]

https://www.standard.co.uk/news/world/air-india-plane-crash-report-investigation-pilot-error-switches-london-gatwick-b1237753.html

[broadgage]

BREAKING NEWS.
No significant faults found with the aircraft or the engines.
Both fuel controls found to be shut off. (according to flight data recorder)
One of the pilots can be heard asking the other pilot why were the switches turned off ? (according to cockpit voice recorder)

Source was BBC^» (British Broadcasting Corporation - home page) TV^▸ (Thames Valley, or TeleVision, depending on context) news at 22-00, Friday evening.

[TonyK]

Reported elsewhere too. From the MSN extract from the Telegraph:

Initial findings from the investigation into the crash indicate switches controlling fuel flow to the jet’s two engines were turned off leading to a catastrophic loss of thrust at take-off.

Amid the confusion, one of the pilots is heard asking the other why he “did the cut-off” to the fuel supply in the recovered cockpit voice recording.  The other pilot responded that he did not do so, according to the report released on Friday night by Indian authorities.

The switches were then moved back to their normal position, which automatically started the process of relighting the engines.

One of the engines was in the process of regaining power at the time the aircraft crashed. The other was relit but was not yet regaining thrust.

“At this stage of investigation, there are no recommended actions to B787-8 and/or GE GEnx-1B engine operators and manufacturers, suggesting that no significant fault has been found with the plane or its engines,” the report reads.

[JayMac]

We now know how the plane crashed. Whether we get the 'why' remains to be seen.

I've attached the interim report to this post. It is compressed so the embedded images may not be clear. Alternatively it can be downloaded from India's Aircraft Accident Investigation Bureau.

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