Posts about: "Action slip" [Posts: 110 Pages: 6]

Musician
July 16, 2025, 07:06:00 GMT
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Post: 11923473
Originally Posted by slats11
Correct if considering all crashes
However by the time obvious mechanical issues, weather etc are excluded, the odds are way higher that 5%
So what are the odds for "crash by brain fart"? for example, when a cargo pilot inadvertantly hits TOGA on descent and then plows the aircraft into the marsh compensating?

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HUD Engineer
July 16, 2025, 07:40:00 GMT
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Post: 11923491
Cutoff Action Slip - Room for improvement?

Originally Posted by YYZjim
The preliminary report narrows things down a lot but not as much as it could have done. The report will have been approved by several people. What we see is their consensus. Why did they choose this version?

The report is written to point the finger directly at: (i) the fuel cutoff switches and (ii) either pilot error or pilot mal-intent using them. The report is not written to point the finger at an electrical or mechanical malfunction.

We have all role-played in our heads what would have been said in the cockpit in different scenarios. The investigating team already knows. They could have disclosed more of the cockpit conversation, which would be a lot of help to us PPRuNers, but didn't need to. They have let Boeing and the type off the hook and put the blame on the pilots. They have fulfilled the primary purpose of an investigation -- to find out what happened.

Interestingly, they did not disclose whether it was error and mal-intent. Perhaps that is because they couldn't answer the grisly question: which is least worst, from the point-of-view of the airline, the victims' families and future customers?

Two posters above have quoted AvHerald's report that "... India's media reports that the investigation is NOT focusing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure." One interpretation of this is that the investigation knows all about the human action and that the system they refer to is the industry's approach to pilot mental heath and well-being.

YYZJim
Originally Posted by mr ripley
I have flown B777 and B787 and have operated these switches many times. They are solid secure switches that need a deliberate action to move.
My thoughts, without any weighting or inference are that they were:
1. moved deliberately to shutdown the engines
2. moved unintentionally and ended up shutting down the engines
Airlines focus on many safety topics, one of which is action slips.
...
The only time that both fuel control switches are switched off together (and not immediately switched back on - Double Engine Failure) is at the end of the flight once parked on stand. This is a very familiar, routine action that pilots do with probably little thought. I have heard of some very odd action slips by some very experienced pilots. In this instance maybe the cue for the action was gear up? It could fit the timeline.
If the vast majority of flights have been made without anyone performing this particular action slip previously, without dismissing it, but giving it due consideration as a risk with potentially deadly consequences on every flight, is there a case for reviewing the procedure at the end of the flight, to cutoff one, count to 5 or 10, and cutoff the other, or have each crew member take care of "their" engine at that point?

I'm assuming that isn't an original idea, so how is it already addressed by Boeing, or the airlines, or pilots?

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JustusW
July 16, 2025, 10:23:00 GMT
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Post: 11923614
Attention, Wall of Text incoming. Take appropriate precautions and fasten your seatbelts!

Originally Posted by andihce
I will say that in reading your earlier post, I came away thinking you were arguing for the unlikelihood of suicide in this case, at least in part because it is unlikely in the world of commercial aviation as a historical fact. If that's not the case, I apologize. But I will add I think other commentary here has fallen into this trap, as discussed in my referenced post.
It is a bit difficult to not appear to use statistics in this fashion when trying to refute people using made up numbers and stories as argument.

Originally Posted by B2N2
I think we can move away from switch mysteriology and muscle memory and simulator games. [...] The CA had taken bereavement leave 3 years ago and according to Indian sources leave for mental health reasons?
If you had read the articles you quoted you might have realized that the basis for these "media reports" is a single individual who "heard from some Air India pilots". The supposed source wouldn't even have any way to actually know about the claimed information. Unless you want to elevate the Company Rumor Mill to hard evidence standard. This stands against:

Originally Posted by za9ra22
TATA, the parent company of Air India, pushed back, saying, “He did take bereavement leave in 2022 following his mother’s death, and his medical records were submitted as part of the investigation, and the preliminary report did not find anything noteworthy.”
Can we please stick to the actual facts, like za9ra22, and not spread baseless rumors that are self contradictory to begin with?

Originally Posted by DutchRoll
Lots of stiff competition for "most implausible theory" going on but I think my favourite so far is "could've mistakenly moved fuel control switches to cutoff when going for gear up selection". Geezus. 🤦‍♂️
I find this a particularly concerning statement coming from someone who claims to be a pilot. Things like "Action Slip" and "Mental Load" should have been covered extensively in any CRM related education. If you think you are exempt from that kind of failure you are rejecting some very costly lessons learned over the last 50 years of accident investigation.

There have been many accidents where unindicated or even counter indicated action was taken by one or more pilots involved. As discussed in the first and second thread extensively many pilots could report incidents where they observed someone retracting flaps instead of gear. There have been major fatal accidents with pilots shutting down healthy engines instead of surging or burning ones. There's good reason the 787 has extensive takeoff configuration warnings, because we have had accidents and incidents with unsafe configurations taken to takeoff, beyond and sometimes even into a crash. Humans make mistakes. It is the goal of Safety Culture to prevent those mistakes from causing harm.

Originally Posted by AirScotia
The. question about enforcing idle throttles before CUTOFF has been discussed voluminously on this thread.
It was certainly mentioned. I'd not say it was discussed in any big way. Someone mentioned that for Embraer this is indeed the default, I haven't really found anything beyond that, despite considering it a worthwhile train of thought and possible recommendation as a result of this investigation.

Originally Posted by Mrshed
But TL;DR - I'd posit that the rate of truly experienced mental health issues experienced in pilots is higher than whatever rate almost anyone is thinking.

Around 12% of people globally have a mental health issue at any given time - even being incredibly conservative, the rate in pilots is clearly going to be at least in single whole figure percentages (which is far from rare).

Obviously the majority of these issues are not going to be those with severe outcomes, but some will. And almost all mental health issues tend to affect cognitive ability to at least some level. Slowness in action and fatigue are diagnostic criteria for many of the most common mental health conditions for example.
This is a topic of actual research: https://www.pmhc.org/research
Currently 12.6% of pilots meet the medical threshold for depression, with a slight but below average difference between males (12.8%) and females (11.4%), with 4.1% of all pilots experiencing recent suicidal thoughts. https://ehjournal.biomedcentral.com/...940-016-0200-6

It should be noted that the utilized test (PHQ-9) is considered insufficient to assess suicide risk. Depending on scoring these values could be about average, or significantly below average. Based on their wording I would expect the latter, because their methodology does not specify severity.*1 Results of 0-4 points suggest no intervention necessary, 5-9 (classified as mild) simply suggest retaking the test after a few weeks. Research shows that for the general public Major Depressive Episodes have a prevalence of ~5-10%, with the prevalence of minor depression being less studied but significantly higher than major depression. There is also significant symptomatic overlap of mild depression with stress related conditions such as "Burnout" (if you know, please don't, this conversation is already complex enough without bringing that in). Considering the prevalence of stress in the industry I am actually surprised the numbers here are not higher. The lesser delta between males and females could be indicative of just such an issue, meaning that based on the data available the number of pilots actually suffering from depression could be less than even the comparably low number reported here. The actual suicide risk is usually orders of magnitude below even that but not easily covered in this data context due to the test used.

Cognitive impact is highly variable depending on the individual, actual symptoms and severity. It would be wrong to assess that 12.6% of pilots are a risk factor from this data. Quite the opposite, in fact. After the Germanwings crash the topic was discussed and has reached the awareness threshold for many. Mild cases usually require little to no intervention beyond raising awareness and helping the brain fix its chemistry through positive reinforcement. This can be as simple as taking PTO, reducing work hours, or focusing on social or physical activities. In the past 10 years these kinds of low impact measures have been made more readily available, most notably during the Covid-19 pandemic and the resulting turmoil.

Further political activity has lead to some positive action as well. I already mentioned the recent success of the Pilot Mental Health Campaign getting legislation through Congress for improvements of the outdated FAA guidelines on mental health in an earlier post. Similar efforts are underway globally, be that internal review within regulatory bodies, or political movements.

Originally Posted by slats11
As a critical care physician (with AVMED background), these last few years we seeing unprecedented rates of self-reported stress, anxiety, depression, and deliberate self-harm. This is being experienced in most western countries (perhaps globally, but I have less direct knowledge of non-western countries). It is absolutely off the scale. In my 35 year career, I have never seen anything like the last 4 years.

Sadly, I am confident this phenomenon will result in more incidents like Germanwings, MH370 and this.
Keeping what I wrote previously in mind I would still caution against extrapolating your personal experiences too far. Having family in the field and having volunteered myself I can certainly relate, albeit with far fewer and less impactful personal experiences. The research is obviously lagging and we haven't really understood the impact of the Covid-19 pandemic generally, let alone in all its intricacies. There is indeed an observable global trend. Some correlation has been shown to climate anxiety, but other factors like the deteriorating condition of international relations as well as a global rise in movements against individual rights are obvious sources for this trend as well.
This is certainly a challenge for healthcare everywhere, but I do not consider the data available to be majorly applicable in the context of aviation over the already very current research closer to the industry and GA. The positive impact of what has been done and is being done is highly likely to outperform whatever global mechanism is at work here. It's certainly a very important field of study, but based on the data I would still consider the industry and regulators as a global whole to be on a positive path.

We can certainly discuss this topic further, but I would not currently see it as likely to be causal in this particular case.

Overall I am still not convinced we are looking at an individuals mental health crisis in this case. I have already detailed the massive differences to all known or suspected cases of pilot suicide at least twice. There is no evidence of mental health issues for the Captain or the FO. There is certainly a strong indication for a human factors cause to this accident. And as mentioned above I find the idea of improving the safety of the Fuel Cutoff Switches a worthwhile topic to discuss. No single action, and I see these two switches as a single action just as much as operating both thrust levers, should be able to cause a major accident. I find it perfectly reasonable to require the Throttle Levers be at idle for the Cutoff Switches to work, and in case of an incorrect setting some sort of alert would be appropriate.

*EDIT*
*1: I missed this in my original readthrough, the cutoff is sensibly set to 10, starting with moderate depression. I'd have to look into the classification scheme but from memory both mild and moderate depression fall into the same category as relevant for the following statements.

Last edited by JustusW; 16th July 2025 at 10:37 .

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Lord Farringdon
July 16, 2025, 11:33:00 GMT
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Post: 11923656
Originally Posted by JustusW

There is no known evidence for the claim of intent. There are documented instances of pilots making fatal mistakes out of the blue. Human Error is by far the more likely explanation.
Are we still going down this road? You (and many others) are saying we all can make mistake...an action slip...right? To use an analogy that is perhaps more familiar to most people, when driving my car I have set the wrong destination into my GPS, I have inexplicably locked my keys in the car, I have driven with the handbrake on and, my favorite, I have put petrol in a diesel car. But when operating a vehicle in a highly critical phase of driving such as entering a busy freeway and merging into high speed traffic, or overtaking with a single lane in each direction, I have never reached down and turned the engine off!! In fact, except for engine start and engine stop, there is never any reason or muscle memory to go anywhere near the ignition keys.

In a similar manner pilots can make errors, some small, some large that subsequently turn into disasters but at the time they thought their act or omission was the right thing to do. They didn't just do something absentmindedly that clearly wasn't the right thing to o.

But you suggest that during a critical phase of flight any highly experienced, professional pilot with thousands of hours under their belt can have an action slip or 'brain fart' and switch off fuel to all engines. Well in that case we should all be very worried and never fly again since every airliner has two crew who by your reckoning could potentially expose their inner 'brain fart' capacity and randomly (but unintentionally) deselect some very important switches during takeoff. I, m sorry but I just don't buy that.

I'd much rather accept that we have a very few CPT Fruit Loop and FO Looney Tunes types out there who are intent on bringing the aircraft down but that the chances of being on a flight operated by them is extremely slim.

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DutchRoll
July 16, 2025, 11:50:00 GMT
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Post: 11923671
Originally Posted by JustusW
I find this a particularly concerning statement coming from someone who claims to be a pilot. Things like "Action Slip" and "Mental Load" should have been covered extensively in any CRM related education. If you think you are exempt from that kind of failure you are rejecting some very costly lessons learned over the last 50 years of accident investigation.

There have been many accidents where unindicated or even counter indicated action was taken by one or more pilots involved. As discussed in the first and second thread extensively many pilots could report incidents where they observed someone retracting flaps instead of gear. There have been major fatal accidents with pilots shutting down healthy engines instead of surging or burning ones. There's good reason the 787 has extensive takeoff configuration warnings, because we have had accidents and incidents with unsafe configurations taken to takeoff, beyond and sometimes even into a crash. Humans make mistakes. It is the goal of Safety Culture to prevent those mistakes from causing harm.
Someone who \x93claims\x94 to be a pilot eh? Let\x92s just accept that I\x92m not going to paste 40 years of military and commercial aviation logbook pages on here to appease your concerns or alleviate your doubts.

Nor do I claim to be exempt from that type of failure. Quite the contrary - I\x92ve experienced it. But I\x92ve never experienced reaching for a completely and utterly unrelated switch/lever in a totally different location such as fuel control switches versus landing gear levers (which are literally at opposite ends of pilot reach) on a Boeing (or Airbus) either in the sim or the real aircraft. Even with gear vs flaps, those errors occur where controls are proximate, or with controls that both involve \x93retraction\x94 (ie a similar action), or which have a similar method of operation, or which look vaguely similar in outward appearance. None of these principles apply here. So please, be my guest and find it as concerning as you like. And with that, you have convinced me to bow out of this discussion. Cheers.

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andihce
July 16, 2025, 13:21:00 GMT
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Post: 11923732
Originally Posted by Mrshed
I may be having a "brain fart" myself here, but do they definitely not?

The timestamps most certainly are not synced so the blue boxes on my image almost certainly need to move a little left or right, but actually when I looked at them before I think it's pretty close.

What is it that makes you think they are out (genuine question!).
As I've previously posted, there is the fact that the ADS-B data (in your diagram) continues long after electrical power from the engines would have been lost. Someone recently posted that the engines don't even need to run down for this to happen, saying that operation of the FCS to cutoff would shut down the engine VFSG's.

As an aside, I have no knowledge of the software used by Flight Aware reporters, but I would be surprised if, at the very least, the computer involved was not set up with NTP (Internet Network Time Protocol) to synchronize its clock. This would set the computer's clock to within a small fraction of a second of correct time. For even greater accuracy, an inexpensive GPS device could be interfaced with the computer.

Last edited by andihce; 16th July 2025 at 13:42 . Reason: typo

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Dimitris
July 16, 2025, 14:26:00 GMT
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Post: 11923766
Originally Posted by tdracer
Not trying to be part of the on-going hamster wheel. But the discussions regarding the odds of this being pilot suicide based on historical rates are missing a very critical statistical point.
Let's just assume that rate of commercial airliner crashes due to pilot suicide is 1 in 100 million departures. Simply put, that means that if you get on a commercial aircraft to fly from point A to point B, the historical odds are that there is a 1 in 100 million chance that your flight will crash due to an intentional suicidal pilot act. However, the historical odds say that the odds of your flight crashing for any reason are several million to one. Since the turn of the century, the fatal cash rate has been something around 1 in 5 million departures.
Now, we know for a fact that the Air India 787 crashed - hence the probability of a crash for this particular flight is not 1 in 5 million - it's ONE! That means the historical odds of this crash being due to an intentional act by a pilot (i.e. suicide) is ~5%, not one in 100 million (obviously a rough number, but you get the idea).

Oh, another to consider with regard to a pilot having a monumental 'brain fart'. We don't know where the pilot's mind was at during the takeoff. Was he focused on the task at hand, or was he preoccupied with the health of his father and what he was going to do about it. About 35 years ago, my one-time fianc\xe9 left me for another guy. I was devastated. Some of my friends were worried that I might attempt suicide, but that never entered my mind. However, I was horribly distracted and my work performance suffered greatly since my mind was not on the tasks at hand. I could have easily done something really stupid that could have endangered my life - such as missing a stop sign while driving or running a red light because I wasn't paying attention.
Originally Posted by Xeptu
I have to say I'm really impressed with your work. It's no co-incidence that this image has been used noting that the rat is deployed which means the generators are already offline,
I'm equally impressed by how quickly No1 engine recovered. I think it's safe to say that this situation is not recoverable, but a truly impressive piece of engineering all the same.
SLF here with engineering background.

Regardless of what happened and why regarding the switches going to off, there is now a documented failure mode of the system that needs mitigation (?):
Fuel switches off at less than XXX ft lead to unrecoverable AC.

If fuel cut off during take off leads to unrecoverable at less than XXX ft or risk of error i.e. switching one vs the other, then inhibit them. I'm putting it too simplistically, but if after V1 the AC is GO and there is a range of altitude/speed that engines loss leads to unrecoverable some mitigation is needed.

In the meantime maybe ban jump seating during such phases of flight regardless of it is relevant to this accident. If there is intention for something like that, less people with access reduces the possibility of happening.

Too much discussion I think for the 10s to bring the switches back to on.... Pilots are not super humans. By that time the situation the AC was at must have been very clear, some hands shaking is expected...

I wonder if based on the data from the flight, sim-runs have been made to see if the situation would be more survivable had the AC 'slammed' itself back to the runway.

--> Any estimation of how many seconds in 'off' would not change the end result? If it is 2-3 seconds, its better to stop discussing if 10s response by pilots was ok or not. The 'why' and 'preventive' of going to 'off' is a lot more important.

Edit: Have been reading tdracer posts for many many years now. Thank you!

Last edited by Dimitris; 16th July 2025 at 14:31 . Reason: avoid post being regarded as 'dry' or confrontational to exceptional professionals on this forum

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1stspotter
July 16, 2025, 14:49:00 GMT
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Post: 11923781
Originally Posted by B2N2
What are the chances of both switches going bad on the same flight?
As stated many times previously the throttle quadrant was replaced well after the 2018 SB.
Quadrants can be replaced for a myriad of reasons, according to the report none that had anything to do with the switches.

If there was even a remote suspicion of the switches being at fault an emergency AD would already have been issued.



Everything in the preliminary report suggest one of the pilots moved both switches seconds after the liftoff to the CUTOFF position.
If there was a 0,0001 percent chance the switches were faulty and could have moved because of gravity of an object hitting is, there would be a safety bulletin released to all B787 operators

There has not been such a bulletin.

The reason why the report does not mention which of the pilots ask " why did you cutoff ? " is unknown. We also do not know why it was written the switches ' transitioned' instead of ' moved' .
My guess it was either for political reasons or because of a possible criminal investigation.

For a pilot there is no reason to set both switches to cutoff without any reason. There was no engine fire. There was no discussion in the cockpit about using the switches.
Nothing. A mistake is extremely unlikely. There is no reason why the hands of a pilot needs to be near the switches. I do not believe in a brain fart.

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za9ra22
July 16, 2025, 15:12:00 GMT
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Post: 11923796
Originally Posted by 1stspotter
Everything in the preliminary report suggest one of the pilots moved both switches seconds after the liftoff to the CUTOFF position.
If there was a 0,0001 percent chance the switches were faulty and could have moved because of gravity of an object hitting is, there would be a safety bulletin released to all B787 operators

There has not been such a bulletin.

The reason why the report does not mention which of the pilots ask " why did you cutoff ? " is unknown. We also do not know why it was written the switches ' transitioned' instead of ' moved' .
My guess it was either for political reasons or because of a possible criminal investigation.

For a pilot there is no reason to set both switches to cutoff without any reason. There was no engine fire. There was no discussion in the cockpit about using the switches.
Nothing. A mistake is extremely unlikely. There is no reason why the hands of a pilot needs to be near the switches. I do not believe in a brain fart.
That almost started so well!

But the report doesn't suggest one of the pilots moved the switches - it avoids that question entirely. Instead, as you correctly state, it says the switches 'transitioned', which is the strangest way to describe a pilot physically switching them off. I could see that as merely cautious phrasing, but it then describes them as 'transitioning' on again.

Admittedly, I'm a bit rusty with this kind of work these days, but I believe (and so does a former colleague) that the reason these actions are described in this way is that there is no evidence discernible (in time for the report) to identify how those switches were moved. Or even - just to be pedantic since they began in RUN and were discovered in RUN amongst the wreckage - that they moved at all.

I'm not drawing any conclusions, just saying that in the absence of any evidence they could report, they didn't report on any evidence, and 'transition' is the choice how to do that.

I seriously doubt the report fails to identify which pilot asks 'why' and which says 'I didn't' for political reasons. There is too wide a constituency of members of the team and no purpose to be gained, but there would be a possibility it isn't mentioned due to potential legal/criminal investigation if it weren't for the fact that it clearly doesn't actually have that effect at all, and isn't in the AAIB-India remit anyway. If they have no evidence of mental health conditions for either pilot, it's a moot question at this stage in any event.

The only way you can read the report as an investigator is that they itemise all the material facts they know, and omit what isn't yet pertinent or known.

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Subsy
July 16, 2025, 18:46:00 GMT
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Post: 11923929
As things stand, our best understanding of how the brain does what it does can often be described rather nicely by Bayesian statistics. For long boring reasons, this means that things we have experienced or done recently can have a disproportionate effect on how we act and how we perceive the world. Everyone is familiar with visual illusions but there are a few cheap tricks in which priming can be used to reasonably reliably adjust someone's prior expectations so they say something that they don't intend. Here are a few examples. All of them will feel like cheap tricks, because they are, but they all also reveal just how easy most of us are to spoof.

Most of these work best when spoken out loud, so it's probably better to try them on someone else if reading them out load doesn't work as well. However, it can sometimes be hard to realize that you've got it wrong and it may need to be pointed out, so double check because you might think you didn't, until you check...

All but one have the same format - undertake a priming exercise and then answer a question.

Ring rang rung, ring rang rung, sing sang sung, sing sang sung. What is the past tense of brought?

How do you spell most? What does that spell? How do you spell most? What does that spell? How do you spell most? What does that spell? What do you put in a toaster?

Whether you've heard it before or not, that gives you a clear sense of how you are being tricked and should make it easy to avoid next time. However, it's missing the point to stop and think about it, you need to answer straight away.

How do you spell silk? What does that spell? How do you spell silk? What does that spell? How do you spell silk? What does that spell? What do cows drink?

How do you spell folk? What does that spell? How do you spell folk? What does that spell? How do you spell folk? What does that spell? What do you call the white of an egg?

Finally, one for the mathematicians: what is the sum of 1000 + 40 + 1000 + 30 + 1000 + 20 + 1000 + 10?

I don't deny that all of these feel a bit silly, but the fact is that saying a word is an intentional ballistic action that involves a wide range of complex actions, such as moving and shaping the tongue, breathing in just the right way and so on. We are all both 'designed' and highly trained to do so and so it's all second nature. Just like cycling a switch. The mental processes underpinning the physical actions are tolerably well understood these days, but the intentional processes underpinning them are only marginally better understood than when Aristotle was first talking about them.

So if you, or anyone you try them out on, is caught out by any of these, especially once they know what is coming and are actively trying not to mess up, it might be worth giving the 'brain fart' theory a little more credence. I'm not saying it's right, but I am saying that there's a long history in aviation of people setting out to do one action and doing another, especially in designs in which the ergonomics wasn't quite right, like the B17 and the Harvard. Sometimes the local ergonomics can be spot on while the whole system, including training, can introduce priming that can have unintended consequences.


Last edited by Subsy; 16th July 2025 at 19:01 .

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JustusW
July 17, 2025, 12:23:00 GMT
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Post: 11924362
Originally Posted by Pip_Pip
To those who find it difficult to accept certain suicide scenarios, the objection often stems from the perceived irrationality. As others have explained, the answer is that rationality is not present - or not in a form that the rest of us would recognise. I once came up with a thought exercise that helped explain it in a way that might satisfy a rational mind.
Originally Posted by OhForSure
I have not posted on here in many years, but I feel compelled to do so now. I am a current 787 pilot and I have previously flown most Boeing types and an Airbus too. I also have an extensive background and qualifications in human factors, training and assessment. Before anybody reads any further, perhaps acquaint yourself with the notion of Occam's razor. That is, the simplest explanation is the most likely explanation. I was certain that after the preliminary report was released the preposterous conspiracy theories would finally cease, but no! It's 2025 and humans can no longer help themselves. In my opinion the captain committed suicide here. Simple.
Saying so doesn't make it so. There is nothing "simple" about pilot suicide, major depression is a complex condition to begin with and the aviation context adds multiple complicating layers of conflicting motivation. I have stated before that depression and suicide are being displayed irrationally here by a number of people. It's simply not a magic explanation you can just wave at any behavior you don't understand. That's not how that works.

All known cases of pilot suicide have indicators that are not present here. In some cases (like the often mentioned Germanwings incident) those indicators were such strong evidence that the criminal case was open and shut in days or weeks. Those weren't "simple" cases either, but they had the evidence one would expect from a pilot suffering such a complex condition. Nothing of the sort is known about either the Captain or the FO.

Suicide is almost always the last step in a long history of suffering from (mental) illness. Suicidal ideation is what the medical field calls thoughts (ideas about) suicide. It's a comparably common symptom shown in around 5-20% of adults worldwide with strong variation correlating with external factors, such as economic well being, occupation, stress, etc. Assessed globally Pilots, as far as relevant studies are available, seem to fall into the lower bracket of prevalence of suicidal ideation with a lower than expected prevalence when compared to the general population from their respective country of origin down to the rate observed in the general population of economically stable and strong countries.

Cases where pilot suicide is suspected (any case where at least some level of evidence is present but either no or only an officially disputed final assessment exists) also generally follow the same patterns. Attempts at concealment are known to happen, but make up only 10%-30% of completed suicides in the general population. This does include the gray area of potentially successful concealment which would lead to the assumption of an accidental death.

In almost all cases a recurring pattern is also the topic of certainty. In suicidal ideation it is a very common theme that any issues are projected into the future and the uncertainty of those issues generates anxiety. Many survivors of suicide attempts reveal that they considered the certainty of their own death to be preferable over the continuance of uncertainty and the associated anxiety. While we are far from being able to authoritatively call this a definitive mechanism in the psychological conditions related to suicide it is strongly implicated and subject of ongoing research. My personal way of explaining this to someone unfamiliar with depression is that your brain is quite literally poisoning you and generating so much trauma that the idea of ending it becomes preferable. Patients in this stage of major depression show a determination and rationality in their drive towards that goal that is often the primary source of perceived irrationality from the outside. They routinely ignore any and all information that is not relevant to their goal. The means are often chosen with preference of perceived certainty over any other motivation, including harm to others.

Summarizing:
1. Suicide is overwhelmingly the last step in a history of mental illness and almost exclusively presents without that in cases of immediate, significant and obvious trauma.
2. Attempts of concealment are of low probability in a suicide.
3. Methods of suicide are commonly chosen based on perceived certainty of success.

These indicators are all negative for the Air India accident. There is no indication of a prolonged history of mental illness, there is no immediate, significant or obvious trauma. Theorizing an attempt at suicide by either of the pilots requires the assumption of a major attempt at concealment. And most importantly: The method chosen is not following the pattern of maximizing certainty, the probable reason why all confirmed and even all suspected cases of pilot suicide happened in cruise flight.

The theory of suicide is thus, in this particular case, a bad fit.

If we are assuming an (intentionally) concealed medical condition there are much simpler and more likely candidates available. Any type of cardiac issue could lead to a clot and a stroke. A stroke fully explains what happened here. A clot triggered by the acceleration of the takeoff run could very reasonably present as a stroke in the timeframe given here. If the victim belatedly realizes what happened he may develop the wish to stop the situation, which in a stroking brain could absolutely lead to the shortcut of "turning off the engines is done at the end of flight". Or the stroke victim is trying to hold onto something and grabs the switches relatively close to the relaxed hand position after releasing the thrust levers at V1. Other conditions can rapidly present and impact judgement, motor function, or both. If we are willing to attribute the Captains recent decision to retire and be with his father as a potential change in character we might even fall into a number of neurological conditions that may be causal.

But there are even simpler explanations than a concealed medical condition. Maybe one of the pilots had previously finished recurring training for evacuations on the runway and had discussed this with his colleague ahead of the flight. The final memory item for those is turning off the fuel pumps. This kind of Action Slip is well documented. It's not very likely, thus I have no issue believing no one reported observing that type of a slip in a simulator, but it's not like accidents with this level of weirdness are common. There is however a good indicator here fitting the situation of at least one of the pilots: The Captain may have been preoccupied with his wish to retire soon and spending time with his father. While the latter makes absolutely no sense in a suicide it could be part of the causality for an action slip. Also note this post about inadvertent activation of switches despite majorly different modes of activation.

In the end here are three observations based on the preliminary report:
1. Any type of mechanical fault is unlikely and no immediately supporting evidence has been found.
2. A human factor is currently the most likely candidate for the cause of the accident.
3. The type of human factor is not being speculated upon in the preliminary report.

Note that the report specifically states:
Complete analysis of postmortem reports of the crew and the passengers is being undertaken to corroborate aeromedical findings with the engineering appreciation.
No further reference is made to any medical conditions, which is expected as these would fall outside the guidelines for inclusion in a preliminary report.

Attribution of an unclear accident to suicide is contributing to a problematic pattern of stigmatization and increases the likeliness of concealment of (mental) health issues associated with that stigma. In addition it precludes proper analysis of a potential inadvertent mishandling of controls. Both Airbus and Boeing commonly utilize this position and type of guarded switch. Both are sufficiently protected against accidental movement but nothing else. In many smaller aircraft setting the Master Switch to Off would not lead to engine shutdown. There are even reports of what we could consider negative training, by flight instructors demonstrating this fact by turning the Master Switch off in flight. Other commercial aircraft utilize different schemes, Embraer was mentioned right at the beginning of this thread by moosepileit as requiring Throttle Levers at idle for Fuel Cutoff as well as positioning those switches on the overhead panel .

Having just done a full review of this entire thread with regard to human factors I find it a bit sad to note that from the start there were multiple people with backgrounds in accident investigation present that pointed out human error and gave proper reasoning or even corroborating evidence in the form of accident reports. There are also multiple people repeatedly injecting their theory of pilot suicide either without providing any evidence or referring to baseless rumors from media reports. Notably those same people often rejected any other possibility of human error. They also repeatedly make statements of fact that are contradicted or not covered by the preliminary report. Any discussion of mental health seems pointless at this moment in time since there is no actual interest in the topic beyond occasionally going "It's suicide, duh". If anyone is interested in the topic I can once again only recommend taking a look at the Pilot Mental Health Campaign Research Page and other resources presented there.

I think the other worthwhile takeaway from this thread has been stated rather early, with the very applicable nod to a better layout regarding critical functionality that has no reason to be present in close proximity to regularly used flight controls.

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Musician
July 17, 2025, 13:34:00 GMT
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Post: 11924410
The issue of intent

Assumed: a pilot moved both fuel switches to CUTOFF, and that caused the accident.

Argument against intent:
1. The CVR, taken at face value, reveals that neither pilot was aware he had moved the switch himself
2. On a G650 simulator, CUTOFF after 10 seconds (then RUN after 10 more seconds) was barely recoverable. ( See upthread. ) This suggests the "unrecoverability" window on the 787 was quite short, making a suicide plan risky.
3. Similar accidents were survivable (someone said upthread).
4. Typically, pilot suicides start with the pilot alone in the cockpit at cruise altitude.
5. "Shut down both engines" is an action that often occurs after a flight, and could thus be learned as "muscle memory", and be subject to an action slip.
6. The airline stated that the captain's medical records were found "unremarkable".

Argument for intent:
1. It's the simplest explanation.
2. "I can't believe any pilot would do this unintentionally, and neither should you."
3. Pilot took 10 seconds to correct his "mistake"
4. Uncorroborated reporting has it that the captain did not sound panicked on the CVR.

Did I miss any points?

To be clear, given the facts in the preliminary report, I could not decide this question today.
Whatever happened in Ahmedabad is not affected by the outcome of our discussion.
I hope that the AAIB and the public prosecutor will gather as much evidence as possible, and then the question can hopefully be resolved from facts.

Last edited by Musician; 17th July 2025 at 14:02 . Reason: link added

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JustusW
July 17, 2025, 17:30:00 GMT
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Post: 11924533
Originally Posted by BrogulT
And (correct me if I'm wrong) I believe you've dismissed the notion of hiding the suicide and making it appear to be an accident, murder, someone elses fault, etc. I think that notion might be more common than you would think (after all if they are successful you wouldn't know...) and probably reflects a significantly different sort of mental issue. A depressed narcissist? IDK.
I fear we could discuss comorbidities until we're blue in the face. But no, I wouldn't dismiss the possibility of it being suicide, no. I just consider it to require any kind of actual prove instead of prove by the inability to come up with better explanations. As for the topic of concealment: It's obviously a grey area but the previously quoted 10-30% prevalence is based on studies trying to figure out exactly that. I certainly wouldn't feel comfortable opining on that number.

Originally Posted by BrogulT
IDK whether you've addressed this earlier, but I'd point out that people with suicidal thoughts are often indecisive .
Originally Posted by ferry pilot
Suicide is often impulsive. A sudden, unplanned leap from a balcony, bridge or precipice is a single motion with almost guaranteed terminal result. Unfortunately an airplane in the hands of a depressed or mentally unstable pilot can also be a single, impulsive motion away from instant, painless death. As demonstrated, a couple of flicked switches and a very short wait.
Unlike previous pilot suicides that took deliberation and often aggressive action, this appears to be a passive event that could have been conceived and executed in the same impulsive instant. Followed almost immediately by regret, denial and even a futile attempt at reversal.
Originally Posted by za9ra22
There's lots, psychologically speaking, wrong with this scenario too. I'd be much more convinced that this was an impulsive act or a psychotic one than that it was a planned suicide, meant to happen this way.
Suicidal ideation does frequently present with both imagined as well as examined scenarios. Especially in more severe cases many victims have a history of attempts. The impulsive variants are typically in lesser severities of depression and are actually more common in people with lower levels of suicidal ideation. It would certainly be the most likely scenario for a suicide that I could come up with. It's especially prone to happen in cases with sudden traumatic events on top of an existing baseline condition but can occur in any other condition as far as I know. It would also fit somewhat with an unremarkable history as a person suffering from mild to moderate depression might consider being able to cope on his or her own. And then obviously be less prepared for a spontaneous urge. The troubling part here is that it would be indistinguishable from an action slip without additional evidence as to the pilots state of mind. The observable scenario would be something like this: Immediately upon reaching v2 the Captain moves both fuel cutoff switches to their off state in quick succession. When queried by the FO he denies having done so and remains passive until impact.

This is a plausible scenario, but also one that would be impossible to determine causally. Try for yourself, but you can use either rationalization for the behavior and even use the same rationalization for the opposite behavior. There is no way to predict how anyone would react in that situation and no way to determine either way what that behavior indicates. Not even moving those switches back into the on position by himself would give a reliable clue as to his state of mind. The report would probably default to Human Error in this case, as the intent could not be determined.
The resulting suggestions, ironically, would be basically the same as well. Ease access to mental healthcare, improve training for avoidance, and most importantly: Improve resilience of systems against this type of action.

Based on the numbers available to us right now I can almost guarantee that if you have taken more than 10 flights in your life one or both of your pilots or colleagues on the other seat suffered from symptoms of moderate to severe depression. And you will with almost absolute certainty never actually know. The true question people need to ask themselves is "Do I want my depressed pilot to have access to psychotherapy or not?"

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Chiefttp
July 17, 2025, 18:24:00 GMT
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Post: 11924559
After 1400 posts, why hasn’t anyone suggested this? EARLY ONSET ALZHEIMERS OR DEMENTIA. . I’ve shared my experience in an earlier post concerning a pilot whose confusion during a sim event was very apparent. This can be a possibility as opposed to the suicide theory.

I think that we will get answers only after a deep dive into both pilots backgrounds and life. As much as this may seem on the surface like a suicide, consider the “Brain fart” theory, or, as I mentioned in an earlier post, a possible early onset Alzheimer’s condition which can cause confusion and irrational actions. I’ve seen this confusion in the sim and I dismissed his erratic actions as incompetence. Only after a thorough investigation into the pilot’s lives, and interviews with friends and families will we get a clearer picture to ascertain the possibility of intentional suicide, brain fart, or early mental impairment. I think the answers will be found there versus design issues with the 787.


Last edited by Chiefttp; 17th July 2025 at 18:37 .

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Subsy
July 17, 2025, 19:28:00 GMT
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Post: 11924599
I've not posted enough to post a link yet, but anyone who fancies googling this:

airbus cockpit control confusion

Will find an Airbus bulletin on action slips.

Obviously, they are not that common, but suicide attempts with another person on the flight deck and during take off seem so uncommon that I can't find a single example on a passenger aircraft.

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sorvad
July 17, 2025, 19:46:00 GMT
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Post: 11924613
Originally Posted by Chiefttp
After 1400 posts, why hasn\x92t anyone suggested this? EARLY ONSET ALZHEIMERS OR DEMENTIA. . I\x92ve shared my experience in an earlier post concerning a pilot whose confusion during a sim event was very apparent. This can be a possibility as opposed to the suicide theory.

I think that we will get answers only after a deep dive into both pilots backgrounds and life. As much as this may seem on the surface like a suicide, consider the \x93Brain fart\x94 theory, or, as I mentioned in an earlier post, a possible early onset Alzheimer\x92s condition which can cause confusion and irrational actions. I\x92ve seen this confusion in the sim and I dismissed his erratic actions as incompetence. Only after a thorough investigation into the pilot\x92s lives, and interviews with friends and families will we get a clearer picture to ascertain the possibility of intentional suicide, brain fart, or early mental impairment. I think the answers will be found there versus design issues with the 787.

Or any number of other brain pathologies for that matter.

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dmba
July 17, 2025, 20:44:00 GMT
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Post: 11924651
Originally Posted by Chiefttp
After 1400 posts, why hasn\x92t anyone suggested this? EARLY ONSET ALZHEIMERS OR DEMENTIA. . I\x92ve shared my experience in an earlier post concerning a pilot whose confusion during a sim event was very apparent. This can be a possibility as opposed to the suicide theory.

I think that we will get answers only after a deep dive into both pilots backgrounds and life. As much as this may seem on the surface like a suicide, consider the \x93Brain fart\x94 theory, or, as I mentioned in an earlier post, a possible early onset Alzheimer\x92s condition which can cause confusion and irrational actions. I\x92ve seen this confusion in the sim and I dismissed his erratic actions as incompetence. Only after a thorough investigation into the pilot\x92s lives, and interviews with friends and families will we get a clearer picture to ascertain the possibility of intentional suicide, brain fart, or early mental impairment. I think the answers will be found there versus design issues with the 787.

what about a flying jam donut depositing monkey toes on the control switches and causing them to lift up by using elephants to fly up and over the lock? Can you rule that out? No, so maybe it happened\x85 let\x92s get real!

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andihce
July 17, 2025, 22:22:00 GMT
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Post: 11924716
Originally Posted by tdracer
Is it really too much to ask that we allow the investigation team to verify and validate their information before we throw someone to the wolves?
I understand the sentiment and sometimes wonder if myself I'm too easily accepting a very damning verdict on what happened, while trying to remain open to alternative possibilities (like the "brain fart" explanation).

We are all of course (perhaps rather morbidly) fascinated and curious about this incident, and trying to reason out what happened with insufficient data - well, at least I am. And to be honest, I am not nearly as concerned about "throwing someone [dead] to the wolves" (to put it rather harshly) than if the pilots had survived and their reputations and livelihoods would be threatened - I have read about plenty of cases where surviving pilots were innocent, even heroic and masterful in their efforts to save life, yet at least in the beginning, were falsely pilloried for what happened.

The difficulty with waiting for the Final AAIB Report comes with the possibility of malicious action. I don't know anything about Indian law, but I would imagine that if this incident had happened in the US, it would already be part of a criminal inquiry (not to mention lawsuits), and not simply under the jurisdiction of the NTSB.

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fdr
August 06, 2025, 15:02:00 GMT
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Post: 11934214
Originally Posted by T28B
Where did I leave my hamster food?

We are discussing the "News" and "Rumor" (R and N) aspect at the moment, given that it's a show, but let's remember to keep it professional (the P).
The CVR "MAY" indicate the "WHAT", it does not give the "WHY", and it is myopic to jump to a conclusion of any action conducted by a human as being deliberate. Our systems assume black and white operation exists, and nothing is further from the truth at any time, location, or situation.

Our training assumes that we always act in the manner that we trained, and that is an optimistic view of life. A review of most serious incidents and accidents leaves an impression that we are all subject to error and action slips. It is also quite true that in more events, the human is the variable that is able to adapt due to the ability to apply heuristics and occasionally intuitive responses to a condition that is outside of their training. Those are the saves, and they tend to be overlooked in our rush for judgement and certainty, and to have some level of assurance that an event cannot occur to us. The defence against error is monitoring system performance, to confirm that when we turn off a say, fuel pumps on an A340-300 to balance fuel (needless action, but sometimes eyepleasing is assumed to be better than leaving stuff alone) and accidentally turn off the HYD pumps, leading to a wild ride, our deliberate actions and cross checking of our movement of any switch, lever, coffee cup etc., is followed by the correct response. All of that is fine, until we do not have time to correct an accidental movement of a system control. FCS are considered to be "irreversible" due to the time to correct an action, and the criticality of the response to the system change, and so we have great checklists and design to ensure that procedurally we check before actioning a switch. That kind of works for engine failure and fire checklists, it gives little comfort to the case of selecting the gear up instead of flaps up, etc., and here is my concern with our assumption of intent from evidence of action.

It may well be that the investigation provides irrefutable and overwhelming proof that the FCS were placed to cutoff. That is looking likely. That in itself does not give the reasoning as to why that occurred.

Collectively we have been flicking the wrong switches (A340 wild rides) and levers, (DC8 etc.,) with lousy outcomes, for quite some time, presumably that is why we take inordinate efforts to check/verify actioning of irreverible systems, and yet, we also misplace keys, put wallets into fridges, etc as we are human. It is one thing to be human, most (not all of us) are, but it is another to understand what the intent of the person involved was, and that means we are a long way from assuming malfeasance or deliberate aforethought.

I do a fair amount of flight testing, and that involves some odd activity, and I don't trust myself to not make slips or errors, to the extent that for one aircraft, I carry a tennis ball that fits neatly over the end of the emergency shutdown handle of the engines that I am not intending to shutdown and subsequetly relight. I don't expect that alone stops making an error, it is simply a procedural step and an opportunity to differentiate between systems that may be worthwhile. We have had similar guards on FCS in the past, due to congnitive lapses leading to red faces, the P3 fuel and ignition switches being an elegant example. The intent of a guard that takes deliberate action is to increase the time available to comprehend what is about to occur, just as putting a post-it note over the LEM jettison is not a bad idea for the late senator of Colorado to have done on Apollo 13.

Just because something happened, doesn't give the reason why, and without that, there can be no "mens rea". It is appropriate to work to understand the why, that is the whole intent of Annex 13.

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tdracer
August 06, 2025, 19:01:00 GMT
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Post: 11934341
Originally Posted by fdr
T
I do a fair amount of flight testing, and that involves some odd activity, and I don't trust myself to not make slips or errors, to the extent that for one aircraft, I carry a tennis ball that fits neatly over the end of the emergency shutdown handle of the engines that I am not intending to shutdown and subsequetly relight.
Having gone on countless flight tests during my career, I was always impressed by the competence and abilities of the Boeing Flight Test Pilots. Most of the flight tests I participated in involved at least one engine shutdown and windmill relight (part of our standard 'First of Model' FADEC software cert flight). The pilots would always use extreme care to make sure they got the correct engine - including putting their hand on the fuel switch and having the other pilot confirm it was the correct switch before setting it to CUTOFF.

But even Flight Test pilots can have a brain fart. Didn't happen to me, but it did happen to one of my best friends. They were doing in-flight start testing of the 757/RB211-535 (and the Rolls engine is a bit notorious for being a fickle in-flight starter). They were doing a corner point condition when the test engine went into a hot start. One of the observers said something like 'it's gone hot, shut it down'. The left seat pilot calmly reached down and shutdown the good engine . Fortunately they were at about 30k, and they were able to recover and get both engines restarted before losing to much altitude.

I was told the Flight Test pilot in question was immediately demoted from "Experimental Flight Test" to "Production Flight Test" (where they do routine shakedown flights of new production aircraft prior to delivery).





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