Posts about: "Fuel Cutoff Switches" [Posts: 827 Pages: 42]

Lonewolf_50
July 12, 2025, 03:04:00 GMT
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Post: 11920127
*sigh*

Let's take the sketchy CVR extract as a given for the moment.

So there's this hard working FO doing the takeoff. He wants to do a good job and impress favorably the Training Captain.

For (reasons that I cannot fathom) the training captain On Takeoff On A Revenue Flight chops the fuel before they get to 400 feet AGL.

Yes, that makes no freaking sense. None. Zero. Zip. Nada.

The natural response from PF to the PM (who is the training captain) is some version of "WTF with the fuel switches?"

And the response is "Uh, no, I didn't do that."

Think about this for a moment.

How many "WTF?" things erupt in your brain if that was the sequence of events?

Full Disclosure: I was in charge of the CRM training for the Navy (all of it) for a couple of years (and yes, that was a couple of decades ago). We got our CRM stuff, mostly, From The Commercial Airline Industry.

But, honestly, that reported back and forth between PF and PM has me smacking my forehead in disbelief... given the advanced state of CRM training in today's airline industry.

I confess to you all: I am more confused by this report than I was by the first two days of "data" eruption after the crash.

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Hollywood1
July 12, 2025, 03:22:00 GMT
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Post: 11920141
Originally Posted by KSINGH

- on take off roll both engines lost power as the fuel cut offs went from RUN to cutoff
Not on the take-off roll. It was 3 seconds after liftoff.

The Vr speed (155 kts) was achieved as per the EAFR at 08:08:35
UTC. The aircraft air/ground sensors transitioned to air mode, consistent with liftoff at 08:08:39 UTC.

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.

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katekebo
July 12, 2025, 03:30:00 GMT
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Post: 11920143
This is pure speculation but I can envision the following sequence of events that would match the timeline and the little we know from the CVR and sequence of events.
- While PF is concentrated on flying the airplane, PNF moves the switches from RUN to CUTOFF in quick succession (for whatever reason).
- PF doesn't notice that the switches have been moved (again, he is concentrated on flying) but soon perceives the loss of thrust and sees a message on EICAS.
- PF looks down to check throttle position. It takes him a couple seconds to realize that the switches are in CUTOFF position.
- PF asks PNF (and his superior) "Why did you cut off the engines?" (or something similar). PNF anwers that he didn't (a lie, but we don't know if deliberate or just confusion / mental breakdown)
- PF realizes that PNF is in a wrong mental state, and attempts to restart the engines. It takes him a couple of seconds to move both switches because his other hand is on the yoke trying to stabilize the airplane.
- By then the airplane has lost too much energy for a successful recovery. One of the pilots calls MAYDAY because he knows that they are about to crash.
This sequence would match the timeline between the initial fuel cutoff, and when the switches were moved back to run position, and would actually indicate great presence of mind and quick decision from the PF.
Again, this is pure speculation but it would match well with the little information we have.

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jimtx
July 12, 2025, 03:34:00 GMT
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Post: 11920144
Originally Posted by LTC8K6
Unless defective, they cannot be operated with a flick of the wrist. They have to be pulled up hard, before they can be moved.
I think this has been explained 80K times.
Unless defective. I only encountered one in a 30 plus year career where my Captain shutdown at block in and did not like the feel and checked that the detent was worn. Wrote it up. But Boeing installed some that did not have a detent and the FAA issued a SAIB, referenced in the Air India mishap report, to check for these switches because they could inadvertently be positioned to off. Whether they meant human or other inadvertent action was not clear.

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13 others
July 12, 2025, 03:38:00 GMT
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Post: 11920147
Originally Posted by Propjet88
...The report mentions that the flight crew on the immediately prior flight had written up a "STAB POS XDCR" status message, and that troubleshooting was carried out. I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead...
Best theory I've seen so far.


Originally Posted by tdracer
I assume the 10 second pause is based on how long it took the two 787 event pilots to realize their error and return the switches to RUN.
I assume the unusual alarm cacophony that erupted after cutting the engines would have been overwhelming. Agree an error in good faith. If bad faith were involved, the switches wouldn't have returned to the run position, or at least they wouldn't have been allowed to remain there.

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MechEngr
July 12, 2025, 03:47:00 GMT
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Post: 11920152
Originally Posted by LTC8K6
Such a fault in a multi pole switch would be odd. And in two switches at roughly the same time?
Typically you'd have a fault in one set of poles, giving you conflicting data.
Such as the EAFR registers a fuel switch in cutoff, but the fuel did not actually cut off.

Don't forget that the RAT deployed instantly, shortly after liftoff, agreeing that both switches were in CUTOFF.
Yes - conflicting data issuing a warning when the system being controlled has no fault. That's a problem at considerable expense for a rare occurrence.

Literally covering all the bases with a video would not only show what the switch status was but also how it got there, if it has an immediate effect, which a second line would not do.

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rab-k
July 12, 2025, 03:48:00 GMT
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Post: 11920154

Originally Posted by Propjet88
I don\x92t know if the FDR measures the switch position or the electrical signal. The latter is probably more likely, although there has been much discussion around potential scenarios involving accidental switch movement as well as possible causes of electrical glitches. Let\x92s assume that the switches were actually moved, and ignoring the \x93bad faith\x94 scenario, we need a situation that encompasses the switches being moved to Cutoff by one pilot, this action being queried by the other pilot and denied by the pilot who moved the switches. For consideration, here is a possible scenario that hasn\x92t been mentioned yet and encompasses the frailty of human performance. The report mentions that the flight crew on the immediately prior flight had written up a "STAB POS XDCR" status message, and that troubleshooting was carried out. I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead. As in all modern Boeings, the Stabiliser Cutoff switches are immediately next to the Fuel Cutoff switches and operate in the same sense (i.e. down for Cutoff). They are guarded and never normally moved but, with an intent to move the stab switches, \x93muscle memory\x94 (cerebellum activation if you prefer) may have taken the Captain\x92s hand to the Fuel switches, which are operated on every flight. The FO (who is PF) is manually flying at this stage sees and queries it. The Capt denies it, as he doesn\x92t realise what he has done (confirmation bias perhaps). After a few seconds, the terrible mistake is realised, and the fuel switches are moved back to run, but sadly too late and the Capt makes a Mayday...
A plausible theory, however, if that were indeed the case wouldn't supporting FDR data be available/have been included in the initial report?

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katekebo
July 12, 2025, 03:56:00 GMT
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Post: 11920159
To those who still try to put the blame on the switches...
- If the switches were defective (wrong type without the detent was installed), this airplane has been in operation for 10+ years - somebody would have noticed.
- If the switches were defective due to wear, it's impossible that both would fail simultaneously at exactly the same time. Have you ever seen all FOUR wheel bearings in a car fail within one second of each other?
- If this was an electric issue (spilled coffee theory), there is no way that ALL electrical contact simultaneously shorted into the exact condition to cut off the fuel. We would see one or two contacts fail first and some kind of "command disagreement", but not a nearly instantaneous total failure. Maybe only if somebody spilled a glass of mercury over the switches ...
The only plausible explanation is that somebody moved them (for a reason unknown).

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nrunning24
July 12, 2025, 04:06:00 GMT
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Post: 11920166
The switches got moved to cutoff, I dont see how anyone can take the audio from the report any other way. There are way to many ECAM warnings in this case for the pilot to know that that's what happened if there was a short or similar software failure. Add to the fact they got put back to run. Why we will find out.

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katekebo
July 12, 2025, 04:07:00 GMT
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Post: 11920167
Originally Posted by Propjet88
I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead.
PJ88
If there was some kind of Stabiliser error message during the timeline of this accident it would certainly be mentioned in the preliminary report. I am sure that the investigators would have noted it and arrived to similar conclusion you did. A Stabiliser error message would be too relevant piece of information to ignore it in the preliminary report.

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B2N2
July 12, 2025, 04:19:00 GMT
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Post: 11920176
It\x92s fascinating to read all the what-ifs, some even more delusional then others.
  • There are no cup holders close to the fuel cutoff switches
  • We don\x92t hand each other tea at rotation.
  • There is no g-force during rotation, we don\x92t jank the airplane of the ground. It\x92s a 3 second rotation to approximately 15 degrees.
  • No worn switch would \x93fall over into cutoff\x94 when pitching up.
  • The trim cutout switches are totally different design and are checked during the cockpit setup
  • The PF places both hands on the yoke at V1 and looks outside and inside at the speed and attitude information throughout V1\x85Rotate\x85Positive rate\x85gear up.
  • In the simulator, the instructor programs a V1 cut at their control station.
  • The CA hands are on the thrust levers and guarding the yoke until the automated V1 call then the thrust levers hand gets pulled off to avoid the temptation of a reject above V1.
  • Headsets are on separate channels on the cockpit voice recorder.
  • The Indian authorities already know who said what and when.
  • Cockpit cameras would have never prevented this, it would have only shown who pulled the switches.

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LTC8K6
July 12, 2025, 04:37:00 GMT
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Post: 11920190
Originally Posted by diclemeg
This is very interesting and a reasonable explanation based on the report.... I think you may be onto something.
I just looked at a picture of the 787 throttle area and I don't see how one would ever confuse the stabilizer cutout switches with the engine fuel cutoff switches. They are completely different in look and feel and operation.

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MaybeItIs
July 12, 2025, 04:41:00 GMT
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Post: 11920192
Originally Posted by Propjet88
The report mentions that the flight crew on the immediately prior flight had written up a "STAB POS XDCR" status message, and that troubleshooting was carried out. I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead.
Excellent point!

Question: I imagine the accident crew /Captain at least would have been aware of this status message, or at least that it had been looked into. Is that fair comment, or known anywhere? Or maybe he even knew what they did, which may well have been FNF.*

I mean, possibly the Captain decided, since he had a young pilot flying, that he would try to avoid any potential Stabiliser problems from startling his junior pilot by pre-emptively cutting off the Stab control while they were still good. And didn't announce the intention because he didn't want to distract the PF, or make him even more nervous. Stuff like this does happen.

If he happened, as you say, to flip the Fuel Cutoffs instead, that's all that would show on the FDR.

Knowing who said what would be a big help.

*Fault Not Found, in case that's not an Aviation acronym.

Last edited by MaybeItIs; 12th July 2025 at 04:56 .

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KSINGH
July 12, 2025, 04:47:00 GMT
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Post: 11920195
Originally Posted by RiSq
The most scary thing here is that, on first glance this looks to be a massive balls up again by a flight crew.

I\x92ll hold judgement till the report is out as stranger things have happened. But what a seismic shift we have seen in the last 30 years.

30 years ago you worried about flying with certain airlines due to their maintenance records and ages of their fleets.

We are now in the time of choosing your airline of choice by having to research their flight routes over questionable airspace or their training schemes of their pilots.


It is rather worrying that the majority of major airline crashes in the last 20 years have been due to the two fleshy ones riding up front, if not questionable flight planning, Military or terrorist input.

I expect thats going to be about as popular as an lead balloon here.

In fact, I cannot remember the last major mechanical failure that led to a mass loss of life.

The Jeju one is still to be determined, but not sure if that can even be counted due to bird strikes.
this is sheer selection bias

Whenever this argument is used (humans are the problem, all modern crashes are because of pilot error) it doesn\x92t account for all of the problems and serious events that humans have avoided and where they\x92ve saved the day. Every airline in the world will have multiple such incidents a year but you\x92ll never hear of them outside of internal comns (maybe the occasional one will be serious enough to warrant external investigations)

still yet to see any evidence this has systematic implications for air india as a whole, if anything after that initial cutoff was \x91transitioned\x92 (we can speculate why or how) the actions of the flight deck (at least one of them) was commendable- with slightly more time they\x92d have flown away.

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KSINGH
July 12, 2025, 04:57:00 GMT
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Post: 11920199
Originally Posted by Chiefttp
My only question is, after close to 40 years flying, on takeoff, if I lost thrust/ Power, my immediate reaction would NOT BE TO CHECK THE FUEL CONTROL SWITCHES. Unless the Pilot flying saw the Pilot monitoring visually reach down and shut the fuel control switches off, which would be odd since as the PF, your attention is looking at the instruments and outside, not inside and downward in the direction of the FC switches. It seems odd how quickly they ascertained the fuel control switches were shut off. No startle factor, or confusion, just a very quick determination that the FC switches were cutoff. Very strange.
yes this is the part that has been bugging me also the more I\x92ve thought about it

It\x92s a little annoying that we don\x92t know who spoke the and who denied about the cutoffs but it\x92s kind of the secondary issue.

The 787 has HUDs, PF is looking straight ahead and \x91up\x92 (as the U in HUD suggests), the cutoff toggles are not at all in his field of view , quite similar for the PM

the CVR transcript will have to reveal a lot more because the current sequence of events doesn\x92t really answer that much other than to rule out a few other theories

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13 others
July 12, 2025, 04:59:00 GMT
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Post: 11920202
Originally Posted by B2N2
The trim cutout switches are totally different design and are checked during the cockpit setup...............No he\x92s not. Any EICAS message would have been recorded.
Originally Posted by LTC8K6
I just looked at a picture of the 787 throttle area and I don't see how one would ever confuse the stabilizer cutout switches with the engine fuel cutoff switches. They are completely different in look and feel and operation........Also, what is the supposed startling event here?
Um, the flap and gear levers are a totally different design and they look, feel, operate differently. They are not even co-located, and occasionally people confuse them, withstanding decades of design efforts.
The fact that EICAS messages were recorded does not mean that they were provided in the preliminary report.

The notion is that around liftoff EICAS reported an error related to an error logged on the previous flight, that the PM felt it prudent to remedy the problem by cutting the stab cutoff switches, inadvertently cutting fuel. Action-slip, as mentioned countless times in these threads.

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Propjet88
July 12, 2025, 05:10:00 GMT
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Post: 11920206
Originally Posted by LTC8K6
I just looked at a picture of the 787 throttle area and I don't see how one would ever confuse the stabilizer cutout switches with the engine fuel cutoff switches. They are completely different in look and feel and operation.
Sorry but the logic you are using is not considering "execution errors" which are not uncommon and, in aviation, can often have bad outcomes. They are, according to James Reason, "...errors which result from some failure in the execution and/or storage stage of an action sequence... \x94 Reason refers to these errors as failures in the modality of action control and, at this level, errors happen because a well - practised (but wrong) routine is activated. e.g. The Training Captain the the Nepal crash feathered the engine when he meant to select the flaps. This type of error is more likely when a person is stressed, fatigued or distracted.

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mahogany bob
July 12, 2025, 05:22:00 GMT
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Post: 11920208
A couple of thoughts

1. if I wanted to crash an ac I would physically fly it into the ground after t/o and NOT toggle a couple of fuel cutoff switches ?

2. these 2 vital fuel cutoff switches seem to be much too HANDILY positioned and easy to operate !

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AerocatS2A
July 12, 2025, 05:25:00 GMT
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Post: 11920211
There are quite a few comments on here along the lines of "no one would do that", "that's highly unlikely", "that's impossible" etc. We need to remember that a highly unlikely event, a dual engine shutdown/fail, has undeniably happened. Given that a highly unlikely event has happened all of the possible unlikely events that could have caused it are actually reasonably likely given that we know the accident happened. Think of it this way, tossing 100 heads in a row is incredibly unlikely and tossing 99 heads in a row is also incredibly unlikely. However, if you happen to toss 100 heads in a row then the incredibly unlikely 99 heads that came before the 100th are a certainty. They had to have happened for the 100 heads to happen.

This accident was caused by an unlikely sequence of events. If it wasn't then similar accidents would happen more often. Therefore we can't rule out possibilities just because they're unlikely. It's worthwhile considering the relative likelihood of different scenarios. For example is it more likely that the fuel switches were turned off due to a selection error or a mechanical failure?

This was not a normal flight. It resulted in an accident. There is little point in blathering on about how a normal crew operates on a normal flight.

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LSACapt
July 12, 2025, 05:27:00 GMT
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Post: 11920213
The cutoff switch movement doesn\x92t look like a procedural error in isolation , more like a symptom of heat, stress, and cognitive load catching up at the worst possible moment. Muscle memory kicks in, hands move before thought does.

At Vr, you\x92re saturated \x97 hot cockpit, high workload, maybe a tech snag pre-departure. You\x92re doing everything right, until your hand isn\x92t.

It doesn\x92t take malice or incompetence. Just a second of invisible overload , and the wrong switch moves.

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