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| LondonSpotter
December 05, 2025, 11:46:00 GMT permalink Post: 12000836 |
Benedict Smith US Reporter
02 December 2025 9:24pm GMT US officials fear Indian authorities are trying to cover up the deadly Air India Plane Crash which killed 260 people. Just one passenger survived when Flight 171 crashed seconds after taking off from Ahmedabad in western India in June, killing 241 traveller and crew, along with 19 people on the ground. US investigators believe the evidence points to Sumeet Sabharwal, the flight’s captain, deliberately crashing the plane, The Wall Street Journal reported. Data downloaded from the Boeing Dreamliner’s black box allegedly shows someone inside the cockpit moved the switches to cut off the engine’s fuel supply. The captain did not then attempt to raise the nose of the aircraft before the crash, the evidence reportedly shows. Some US officials fear the Indian government will seek to obstruct the findings and instead blame mechanical faults with the plane. However, Indian observers believe the US is overlooking flaws in American-made planes, although no Boeing Dreamliner has ever suffered a fatal crash before. India’s top court this month said Sabharwal was not to blame for the disaster. Sabharwal’s father has said his son has been the target of a “character assassination” despite his “unblemished 30-year career” as a pilot. The joint-investigation between India and the US, which is involved because the Boeing was manufactured in the US and approved by American safety regulators, has been marred by mutual suspicion between officials. GVG Yugandhar, who leads India’s aircraft accident investigation bureau, is said to have told US officials they were “not a third world country” and “can do anything you all can do”. Indian authorities are accused of failing to prioritise gathering and analysing data from the black box, although this has been disputed by a figure familiar with India’s investigation process. American investigators were banned from taking photos of the wreckage, some of which was moved before they could examine it, sources said. Two American black-box specialists who landed in New Delhi in June were warned not to accompany Indian authorities to a remote laboratory to analyse flight data and voice recorders from the cockpit. Jennifer Homendy, the chairman of the US National Transportation Safety Board (NTSB), is said to have been worried about the safety of US personnel and equipment given the risk of terrorism or military conflict in the region. Indian officials had pushed to analyse the black box in the small town of Korwa, which they deemed better equipped and located away from media attention. Ms Homendy argued that authorities should download data from either their laboratory in New Delhi or work in the NTSB’s Washington facilities. In the end, Indian authorities agreed to analyse the data from the New Delhi site after the US threatened to pull their support from the investigation. Ms Homendy’s calls to her counterpart, Mr Yugandhar, for updates are said to have gone unanswered. Last edited by T28B; 5th December 2025 at 13:32 . Reason: Please use the quote function in the future, thank you, removed picture captions Subjects
Fuel (All)
Fuel Cutoff Switches
NTSB
Wall Street Journal
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| Pilot DAR
December 23, 2025, 22:27:00 GMT permalink Post: 12010158 |
Let's recall what the AI-171 preliminary accident report said:
.....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.
Subjects
AI171
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
RAT (All)
RAT (Deployment)
RUN/CUTOFF
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| Musician
December 24, 2025, 08:41:00 GMT permalink Post: 12010285 |
For the FDR to record the switch moving, while the engine responds to the switch moving, requires two different circuits on different poles of the switch to change state at the same time. This could only be achieved by flipping the switch. I have also never heard of a solenoid (such as driving the fuel valve) to be actuated by solar radiation. I understand that the fuel cut-off part of the circuitry is entirely analog (happy to be corrected if not). Subjects
FDR
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
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| VicMel
December 24, 2025, 12:22:00 GMT permalink Post: 12010375 |
Only 1 Failure
Like all theories that have been around so far it does not explain crucial parts of the accidents.
Most important: Why did the DFDR record a fuel shutoff commanded by the switches on the flight deck. Furthermore: There is more than one source for the Air/Ground logic for the TCMA. There are two engines with two FADECs each. A bit flip, which might be very remotely possible, is not enough to trigger that sequence of events. Furthermore they were more or less on the ground - the A320 affected by solar flare was at FL350 which makes a huge difference. Last edited by VicMel; 24th December 2025 at 12:25 . Reason: missed out "with" Subjects
DFDR
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
Relight
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| TURIN
December 24, 2025, 12:33:00 GMT permalink Post: 12010381 |
The Landing Gear System I am familiar with determined and set WoW status, as well as computing aircraft weight from a load cell situated on the LG structure. Only one system, only one bit for WoW status, just one failure; then the TCMA does the rest. I read somewhere that the Pilots tried to do an engines restart by recycling the fuel cutoff switches, so I have no idea where the switches might have ended up - but TCMA does not care!
The preliminary report as quoted above states that the fuel cut off switches were set to off. Some seconds later, the report goes on to say, the switches were returned to the on positions. The engines reacted to the switch positions, the switches were not moved as a reaction to the engines doing something they shouldn't. This TCMA red herring is becoming tiresome. Please stop and wait for the final report. Subjects
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
Preliminary Report
Relight
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| Musician
December 24, 2025, 16:01:00 GMT permalink Post: 12010436 |
The Landing Gear System I am familiar with determined and set WoW status, as well as computing aircraft weight from a load cell situated on the LG structure. Only one system, only one bit for WoW status, just one failure; then the TCMA does the rest. I read somewhere that the Pilots tried to do an engines restart by recycling the fuel cutoff switches, so I have no idea where the switches might have ended up - but TCMA does not care!
The EGT was observed to be rising for both engines indicating relight. Engine 1\x92s 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.
Please do read the preliminary report, it is the best source we have, and any question you might have regarding what it says are on topic here. TCMA is not mentioned because none of the conditions it needs to trigger were part of the accident sequence (it's more than WoW).
Subjects
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
Preliminary Report
Relight
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| NOC40
December 24, 2025, 17:12:00 GMT permalink Post: 12010461 |
A week ago the BBC reported that 2025 was the sunniest year for the UK since records began; back in August I was diagnosed with a small spot of non-aggressive skin cancer, it is probably not a coincidence! This led me to think - could the Air India 171 crash be due to solar radiation? .
The reason "solar radiation" wasn't mentioned in the Air India report was because the fuel supply to both engines was cut off. Subjects
BBC
Fuel (All)
Fuel Cutoff Switches
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| Leonakua
December 24, 2025, 17:48:00 GMT permalink Post: 12010481 |
Correction... The report was "switches
t
ransitioned to CutOff". Given the Ambiguous nature of the prelim in general, the team may have meant "valves transitioned to cut off". Which is what happened. I wouldn't bother with this, but what is posted tends to become gospel. I think the report is sloppy, and quite possibly purposefully so. So basing a discussion on it is a waste of time. 2\xa2
Yeah, just give me a 01 second.... Oh yeah, "Why did you Cut Off?" ( Fuel not mentioned ) And, wasn't RAT deployed prior to "transition" ? Last edited by Leonakua; 24th December 2025 at 18:00 . Subjects
Fuel (All)
Fuel Cutoff Switches
Pilot "Why did you cut off"
RAT (All)
RAT (Deployment)
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| tdracer
December 24, 2025, 19:19:00 GMT permalink Post: 12010502 |
Correction... The report was "switches
t
ransitioned to CutOff". Given the Ambiguous nature of the prelim in general, the team may have meant "valves transitioned to cut off". Which is what happened. I wouldn't bother with this, but what is posted tends to become gospel. I think the report is sloppy, and quite possibly purposefully so. So basing a discussion on it is a waste of time. 2\xa2
Yeah, just give me a 01 second.... Oh yeah, "Why did you Cut Off?" ( Fuel not mentioned ) And, wasn't RAT deployed prior to "transition" ? When you need invent stuff (or new meanings) for your hypothesis to work, it's time come up with a new hypothesis... Last edited by tdracer; 24th December 2025 at 19:41 . Subjects
Fuel (All)
Fuel Cutoff Switches
Pilot "Why did you cut off"
Preliminary Report
RAT (All)
RAT (Deployment)
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| Ver5pen
January 24, 2026, 18:30:00 GMT permalink Post: 12026533 |
Non-paywalled version:
https://www.aol.com/articles/sabotag...060100148.html
There's the old "the RAT deployed early" (assuming it always takes a full 6 seconds to spool up), the water leak, the "can't move both switches in a second", and new "the aft FDR looks like it burned before the crash". And this, which is as yet unsubstantiated, and is likely not relevant at all:
Just 15 minutes before take-off, the aircraft\x92s bus power control units (BPCUs), which manage the electrical systems, sent real-time signals to Boeing and Air India indicating malfunctions with both BPCUs.
In isolation, none of these problems is classed as major issues, but taken together, according to some experts they show a pattern of electrical problems that point to issues with the core network.
According to reports in India, in the minute before the aircraft took off, and almost certainly as it was heading down the runway, the 787\x92s aircraft communications addressing and reporting system sent a fault code to Boeing and Air India which indicated that the Fadec was receiving corrupted data from an engine monitoring probe.
Pierson says: \x93That aircraft was sending out fault messages before it took off. That is a big red flag. The aircraft health management system was also sending real-time data to Air India and Boeing so they had that information before the fires were even put out. None of that information was included in the preliminary report.
I still don\x92t believe we have got a clear answer on the recording interval of the engine cutoff switch channel, if it\x92s 1s then the \x91debunking\x92 by saying it can be done very quickly is moot as (near) instant would record as 1s I believe and the RAT element is obviously very relevant, if RAT deployment is not recorded then one has to infer when it deployed based on when it delivered hydraulic/electric capability. And this will come down to counting seconds, any indication that the RAT may have deployed before the fuel cutoffs were recorded as moved is obviously hugely consequential it\x92s easy to dismiss these narratives as vested interests but let\x92s be honest everyone has a vested interest here and blaming the pilots has been the go to when in doubt for a very very long time- probably as long as aviation has existed in the absence of explicit evidence (does the CVR have more to tell?) of deliberate action or pre-planning this is a horrifically complicated investigation as there will always be plausible deniability on all sides and different courts/judges will rule on it very differently based on their own biases and views Subjects
CVR
FDR
Fuel (All)
Fuel Cutoff Switches
Preliminary Report
RAT (All)
RAT (Deployment)
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| Someone Somewhere
January 24, 2026, 20:21:00 GMT permalink Post: 12026564 |
Non-paywalled version:
https://www.aol.com/articles/sabotag...060100148.html
There's the old "the RAT deployed early" (assuming it always takes a full 6 seconds to spool up), the water leak, the "can't move both switches in a second", and new "the aft FDR looks like it burned before the crash". And this, which is as yet unsubstantiated, and is likely not relevant at all:
whilst intentional action is the most obvious explanation one can’t ignore data and technical grounds if one is also going to dismiss counter theories on technical grounds
I still don’t believe we have got a clear answer on the recording interval of the engine cutoff switch channel, if it’s 1s then the ‘debunking’ by saying it can be done very quickly is moot as (near) instant would record as 1s I believe
and the RAT element is obviously very relevant, if RAT deployment is not recorded then one has to infer when it deployed based on when it delivered hydraulic/electric capability. And this will come down to counting seconds, any indication that the RAT may have deployed before the fuel cutoffs were recorded as moved is obviously hugely consequential
The engines ran down after the switches were recorded moving. Even if the RAT deployed, that does not suggest that the crew switched the engines off because of an engine failure. No crew is going to shut down the engines down simply because a RAT deploys unexpectedly.
it’s easy to dismiss these narratives as vested interests but let’s be honest everyone has a vested interest here and blaming the pilots has been the go to when in doubt for a very very long time- probably as long as aviation has existed
in the absence of explicit evidence (does the CVR have more to tell?) of deliberate action or pre-planning this is a horrifically complicated investigation as there will always be plausible deniability on all sides and different courts/judges will rule on it very differently based on their own biases and views I don't think you can or will effectively prove whether it was intentional or some kind of an action slip, and by which pilot. I think the accident report will be able to very clearly and with no reasonable doubt show that the switches were physically moved. From the article:
The alternative is
too awful for them to contemplate
: that one of the pilots murdered hundreds of people as collateral damage in a suicide.
Because the aft flight recorder was destroyed, investigators cannot retrieve the one piece of information that it alone contained – the moment it stopped working, which might have provided a vital clue about a fire or electrical failure in the moments before the crash.
The aft EAFR was substantially damaged and could not be downloaded
through conventional means.
The CPM was opened to inspect the memory card. The damage was extensive.
Last edited by Someone Somewhere; 24th January 2026 at 20:32 . Subjects
APU
Action slip
CVR
DFDR
EAFR
Electrical Failure
Engine Failure (All)
FDR
Fuel (All)
Fuel Cutoff Switches
NTSB
Preliminary Report
RAT (All)
RAT (Deployment)
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| Someone Somewhere
January 25, 2026, 06:41:00 GMT permalink Post: 12026747 |
Selecting the fuel system controls (i.e. fuel pumps) off will not work
AFAIK
, as the engines will gravity/suction feed under most circumstances.
Fire handle will work as the backup shutdown. As the fire handle is not regularly used, I don't think action slips are inadvertently going to operate them. Option A is to ignore the cutoff switch unless the thrust lever is at idle - Embraer already does this. Option B is a landing-gear-lever style solenoid interlock on the cutoff switches. Unless the aircraft is on ground and slow, that engine has failed, or that engine has a fire warning, you have to push override. I think Jeju have fairly conclusively shown that you need to not switch an engine off within ten seconds. If you want a system to stop the pilot(s) deliberately and competently crashing the plane (as is posited for MH370), it gets much much harder. I posted some thoughts about that in the 'too much automation' (IIRC) thread, but it boiled down to needing a lot of redundancy and a self-flying aircraft. Enforcing 'must have M of N enabled' is the easy part. Subjects
Action slip
Fuel (All)
Fuel Cutoff Switches
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| Someone Somewhere
January 25, 2026, 09:43:00 GMT permalink Post: 12026797 |
The responses to the article are very interesting. And pretty much go to reaffirming my point about vested interests.
it was the same with the MH370 accident. If you’re American or worked/flew Boeing aircraft you’re more likely to blame the pilots. If you’re Indian or Asian you’re more likely to blame the aircraft. Unless someone produces a smoking gun, which is very unlikely, then the causes will always be up for debate. Here in the U.K. we had the Chinook crash, where the pilots were instantly blamed. It makes me very uncomfortable to blame one individual for mass murder without a smoking gun as such. We had some discussions over in 787 GEnx loss of aircraft data will result in engine shutdown which I won't repeat in full, but there doesn't seem to be any credible way to get that result from a system failure without dealing in one-in-a-quadrillion events. The monitoring channel going to the RDCs and EAFRs is independent from the relay logic that closes the fuel valves. Most of the "we'll never know" accidents don't have full FDR and CVR data. This one does. I'm usually not on Boeing's side but the evidence is pretty overwhelming here. Subjects
CVR
EAFR
Engine Failure (All)
Engine Shutdown
FDR
Fuel (All)
Fuel Cutoff Switches
GEnx (ALL)
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| Musician
January 25, 2026, 09:58:00 GMT permalink Post: 12026812 |
The responses to the article are very interesting. And pretty much go to reaffirming my point about vested interests.
it was the same with the MH370 accident. If you’re American or worked/flew Boeing aircraft you’re more likely to blame the pilots. If you’re Indian or Asian you’re more likely to blame the aircraft. Unless someone produces a smoking gun, which is very unlikely, then the causes will always be up for debate. Here in the U.K. we had the Chinook crash, where the pilots were instantly blamed. It makes me very uncomfortable to blame one individual for mass murder without a smoking gun as such. It's incorrect to say we're blaming the pilots; the prevailing opinion seems to be that ONE pilot (but we don't know who) inadvertantly flipped the switches in lieu of another task ("action slip"). It's incorrect to call this "mass murder", and I don't think anyone did (and stayed unmoderated). It's also incorrect to say there's no smoking gun: the preliminary report is very clear that the fuel cutoff switches transitioned, i.e. somebody moved them such that one set of contacts was registered by the electronics and the FDR, and another set of contacts operated the fuel valve. The whole accident sequence follows from this logically and without contradictions. It is clear that MH370 deviated off course intentionally, but we cannot say if a pilot planned this, or if the aircraft was hijacked. It is false to say that the pilots were blamed "instantly" for the 1994 Chinook crash; the RAF board of inquiry did not do that. That ruling was overturned at first, but two subsequent inquiries re-overturned that, so that the pilots stand exonorated today. Please do review the facts. Subjects
Action slip
FDR
Fuel (All)
Fuel Cutoff
Fuel Cutoff Switches
Preliminary Report
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| Kiltrash
January 25, 2026, 11:32:00 GMT permalink Post: 12026852 |
The bottom line will be in the report as" The fuel switches were operated incorrectly for reasons unknown "
Like the Marie Celeste it will be one of the great unknowns Subjects
Fuel (All)
Fuel Cutoff Switches
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| Jonty
January 25, 2026, 11:50:00 GMT permalink Post: 12026864 |
Subjects
Fuel (All)
Fuel Cutoff Switches
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| Someone Somewhere
January 26, 2026, 07:33:00 GMT permalink Post: 12027289 |
I don't think we have any real evidence for intentional vs action slip. From what I've seen, the moderation has been light since the preliminary report came out showing the cutoff switches were used.
From what I've seen here, the consensus is somewhere around 70% intentional 30% action slip. I agree that we're unlikely to ever know; several of the discussions around cockpit video recorders were kicked off by that. Last edited by Someone Somewhere; 27th January 2026 at 05:02 . Subjects
Action slip
Fuel (All)
Fuel Cutoff Switches
Preliminary Report
Thread Moderation
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| DBYO
January 26, 2026, 11:40:00 GMT permalink Post: 12027436 |
The idea is to protect the engines against
inadvertant
dual shutdown in some way.
(There's always another way to deliberately crash an aircraft.) The problem is, what do you do when the shutdown protection fails and doesn't let you shut down an engine you really need to shut down? Action slips generally result from confusing two different but frequently-performed actions. The obvious safety mechanism is to ensure that use of the cut-off switches is not a frequently-performed action. Future aircraft designs could move the end-of-fight engine shutdown process to a software screen, leaving the use of the physical buttons for emergencies only. I agree that addressing potential deliberate action is far more challenging. Subjects
Action slip
Engine Failure (All)
Engine Shutdown
Fuel (All)
Fuel Cutoff Switches
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| ignorantAndroid
January 26, 2026, 22:24:00 GMT permalink Post: 12027684 |
Unless the CVR captured the sounds of a physical struggle. I suspect that those who have heard it have a better understanding of what happened than we do.
Subjects
CVR
Fuel (All)
Fuel Cutoff Switches
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| Someone Somewhere
February 01, 2026, 20:55:00 GMT permalink Post: 12030826 |
The switches IIRC have both 'run' and 'cutoff' contacts monitored. So if the switches are moved to cutoff, the 'run' contacts open, and the 'cutoff' contacts close.
If
(big if), instead, loss of power resulted in switches appearing open, you would see both 'run' contacts and 'cutoff' contacts as open, which would be a fault.
With no power, the RDCs reading those switch contacts would of course also be unpowered, so you would expect to simply get no data. If the switches appeared to close when the RAT came online, then how would you explain:
It's a nonsense theory with ChatGPT written all over it. It's been discussed at some length previously. Subjects
Fuel (All)
Fuel Cutoff Switches
RAT (All)
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