it makes sense to me that the pilot who said "I did not do it" actually did do it without realizing it, was supposed to be putting the landing gear up when he committed a muscle memory mistake. it happened around the time the landing gear should be up, and this explanation matches what was said in the cockpit, and the fact that the landing gear wasn't retracted. I think this idea was even floated initially by the youtube pilot/analysts I watch but dismissed as unlikely.
The landing gear lever is rather prominently featured in the 787 in a panel central to the cockpit layout so that either pilot can easily reach it. For decades and across many manufacturers, the landing gear lever has traditionally featured a knob that deliberately resembles an airplane wheel. It's very hard to mistake it for anything else. It's actuated by simply moving it up or down.
The fuel control switches are behind the throttle stalks above the handles to release the engine fire suppression agents. These switches are markedly smaller and have guards on each side protecting them from accidental manipulation. You need to reach behind and twirl your fingers around a bit to reach them. Actuating these switches requires pulling the knob up sufficiently to clear a stop lock before then rotating down. There are two switches that were activated in sequence and in short order.
The pilot monitoring is responsible for raising the gear in response to the pilot flyings' instruction.
I would find it very difficult to believe this was a muscle memory mistake. At the very least, I would want to more evidence supporting such a proposition.
This idea strikes me as even more unlikely than someone shifting their moving vehicle into reverse while intending to activate the window wipers.
One of the nice things about finally having the preliminary report is I get to stop hearing all of the same assumptions/theories/YouTuber said/"a guy I know got a leaked report"/etc in water cooler talk at work because the preliminary report solidly disproved all of them so far. If anyone even had and stuck with an idea matching this report it wouldn't have stood out in the conversations anyways.
The collection of comments on this post remind me it'll just be a brand new set of random guesses until the final report is released. Or worse - the final report reaches no further conclusions and it just has to fade out of interest naturally over time.
It's human nature to want to guess at possible explanations for things that are unusual and unexpected.
If hearing those guesses annoys you, nobody is forcing you to read through comments on a thread of people making them! (I hope - sorry if you are being forced after all.)
> There is no possible way to confuse these two actions.
This is obviously an overstatement. Any two regularly performed actions can be confused. Sometimes (when tired or distracted) I've walked into my bathroom intending to shave, but mistakenly brushed my teeth and left. My toothbrush and razor are not similar in function or placement.
That's just your brain associating the bathroom with the act of brushing your teeth, and therefore doing it automatically upon the trigger of entering the bathroom. It bears no resemblance to the accidental activation of a completely different button.
The other poster's correction: "it’s like brushing your teeth with razor" is apt. Touching the fuel cutoff switches is not part of any procedure remotely relevant to the takeoff, so there's no trigger present that would prompt the automatic behavior.
Good analogy. Things I do every day in front of the mirror, but I occasionally attempt to squeeze some soap on my toothbrush. Or I have to brush my teeth and I find my beard foamed up. Or I walk out of the shower after only rinsing myself with water.
If someone confused their steering wheel for the brake you'd probably be surprised - there are indeed errors that are essentially impossible for a competent person to make by mistake. No idea about the plane controls, though.
Even in modern "fly by wire" cars the steering wheel and brake pedal have an immediate effect. They are essentially directly connect to their respective control mechanisms. As far as I understand both of the plane controls on question just trigger sequences that are carried out automatically. So it's more like firing off the wrong backup script than scratching the wrong armpit.
Not really, though. They're both (retracting the gear, and cutting off fuel) just toggle switches, as far as your brain's conscious mechanisms go. Doing them both on every flight dulls the part of your brain that cares about how they feel different to perform.
(I'm not strongly arguing against the murder scenario, just against the idea that it's impossible for it to be the confusion scenario.)
Genuinely curious - could heavy marijuana use cause confusion between landing gear and fuel cutoff? Or some other drugs? (Wondering if they screen pilots for alcohol before they board an aircraft.)
The other day I was eating dinner while chatting with my partner. I finished eating and needed to pee and throw away the fast food container. I walked straight to the bathroom, raised the toilet lid and threw the fast food container right into the toilet.
Those are caused by operating the same lever in a slightly different manner. Not comparable to two completely differently designed levers placed far apart.
Same goes for accidental acceleration instead of braking. Two of the same kind of lever right next to each other.
Accidental acceleration while intending to turn on the wipers would be a fitting example, I don't think that happens though.
Think of the action as a stored function. Maybe they’ve always recalled the function as part of a certain list. It can be a case where the lists get confused rather than the modality of input (lever etc)
Because there's no difference in actions needed to do so. A similar mistake is throwing away a useful item while holding onto a piece of trash. The action is the same, it's just the item in question that's different.
This is not what happened here at all. The actions needed to activate the fuel cutoff switches are not similar to any other action a pilot would want to make during takeoff.
How about actual switch covers (and switches that are not located right in the same area as stuff you are using routinely) instead of a glorified detent? Though I suspect this would also succumb to muscle memory
What about up on the overhead panel where the other engine start controls are?
Or (at the cost of complexity) you could interlock with the throttle lever so that you can't flip the cutoff if the lever isn't at idle
Also the fire suppression system is a different activation (covered pull handles I think)
"Sent into terrain in seconds by flipping a switch" is both too inaccurate and feels too cursory to take as impetus for serious design criticism, especially when the extensive preliminary report explicitly does not recommend any design changes with the current information.
And a gun that doesn't let you point it at your face. And a knife that doesn't let you cut yourself. And a car that doesn't let you accelerate into a static object. And...
Is there a video feed of the cockpit inside the black box?
If not there should be one as even my simple home wifi camera can record hours of hd video on the small sd card. And If there is, wouldn't that help to instantly identify such things?
No neither black box stores video. One stores audio on flash memory and the other stores flight details, sensors etc.
I don’t think video is a bad idea. I assume there is a reason why it wasn’t done. Data wise black boxes actually store very little data (maybe a 100mbs), I don’t know if that is due to how old they are, or the requirements of withstanding extremes.
This isn’t true. This was a 787. It does not use a separate recorder for voice and data (CVR, FDR).
(Most media outlets also got this wrong and were slow to make corrections. )
Rather, it uses a EAFR (Enhanced airborne flight recorder) which basically combines the functions. They’re also more advanced than older systems and can record for longer. The 787 has two of them - the forward one has its own power supply too.
There should be video as well, but I’m not sure what was recovered. Not necessarily part of the flight data recording, but there are other video systems.
That's really interesting. From reading air crash reports there's a lot of times I've seen."Nothing is known about the last 30 seconds because the damage broke the connection to the flight recorders in the tail"
In the US, the NTSB has been recommending it for over 20 years. The pilot unions have been blocking it, due to privacy and other things.
I'm not in aviation. But my between-the-lines straightforward reading is that unions see it as something with downsides (legal liability) but not much upside. It could be that there are a million tiny regulations that are known by everyone to be nonsensical, perhaps contradictory or just not in line with reality and it's basically impossible to be impeccably perfect if HD high fps video observation is done on them 24/7. Think about your own job and your boss's job or your home renovation work etc.
Theoretically they could say, ok, but the footage can only be used in case the plane crashes or something serious happens. Can't use it to detect minor deviations in the tiniest details. But we know that once the camera is there, there will be a push to scrutinize it all the time for everything. Next time there will be AI monitoring systems that check for alertness. Next time it will be checking for "psychological issues". Next time they will record and store it all and then when something happens, they will in hindsight point out some moment and sue the airline for not detecting that psychological cue and ban the pilot. It's a mess. If there's no footage, there's no such mess.
The truth is, you can't bring down the danger from human factors to absolute zero. It's exceedingly rare to have sabotage. In every human interaction, this can happen. The answer cannot be 24/7 full-blown totalitarian surveillance state on everyone. You'd have to prove that the danger from pilot is bigger than from any other occupation group. Should we also put bodycam on all medical doctors and record all surgeries and all interactions? It would help with malpractice cases. How about all teachers in school? To prevent child abuse. Etc. Etc.
Regulation is always in balance and in context of evidence possibilities and jurisprudence "reasonableness". If the interpretation is always to the letter and there is perfect surveillance, you need to adjust the rules to be actually realistic. If observation is hard and courts use common sense, rules can be more strict and stupid because "it looks good on paper".
You also have to think about potential abuses of footage. It would be an avenue for aircraft manufacturers, airlines, FAA, etc to push more blame on the pilots, because their side becomes more provable but the manufacturing side is not as much. You could then mandate camera video evidence for every maintenance task like with door plugs.
I wonder how the introduction of police body cam footage changed regulations of how police has to act. Along the lines of "hm, stuff on this footage is technically illegal but is clearly necessary, let's update the rules".
In fact, you could add some AI to it, even, as an embedded system with a decent GPU can be bought for under $2000. It could help prevent issues from happening in the first place. Of course airgapped from the actual control system. But an AI can be very helpful in detecting and diagnosing problems.
This is exactly how the investigations are NOT conducted. You don't find the evidence that confirms your theory and call it a day when the pieces sorta fit together. You look solely at the evidence and listen to what they tell you leaving aside what you think could have happened.
Landing gear controls are nothing like the fuel shutoffs. And they are in completely different locations. Landing gear controls are in front of the throttle, fuel shutoffs are aft of the throttles.
Is that "nothing like" though? You are saying they are in different places, ok, but are they similar in other ways? Are both controls the same shape? size? colour? texture?
Respectfully, it's not up to other people to disprove your toy theory. The question you're asking here can very easily be answered with a quick Google search.
The short answer is that they are _very_ different controls, that looks and operate in a completely different way, located in a different place, and it's completely unrealistic to think a pilot could have mistaken one for the other.
Different controls with different t shapes, operated in different ways, of different number, different size, and very different positions. One is down almost on the floor, and well rearward, the other is at stomach height and well forward.
The fuel cutoffs also require pulling the control out and over a guard.
I don't think the theory is that the muscle memory sequences resemble each other.
Instead, it's that because muscle memory allows you to do things without thinking about it, you can get mixed up about which action you meant to perform and go through the whole process without realizing it.
They're pilots, they do hundreds of stops each year. In case of domestic pilots, even thousands. And with years of experience, switching off fuel control switches is basically muscle memory at this time now.
That's a ridiculous analogy. The pilots aren't sitting in front of a uniform set of keys that they need to press in a specific order with a specific timing.
The mistake equivalent to what the pilot supposedly did would be if the pianist accidentally stuck a finger up his nose instead of playing the notes or something.
Quite, but the point is that even after doing something correctly a thousand times, someone can make a mistake that seems unbelievable.
The cutoff switches are operated every flight so the muscle memory is there, ready to be triggered at the wrong time.
All we know is that something went wrong in the pilot's head in at least a single moment that caused him to perform a ground action during takeoff.
Depressive murder-suicide is one possible explanation. Altered mental state is another: insomnia, illness, drugs/medications could all explain an extreme brain fart. Perhaps he just had food poisoning? It's India after all.
I keep reading "muscle memory" but the theory that one pilot shut down the engines instead of performing another action has nothing to do with muscle memory.
Muscle memory allows you to perform both actions effectively but doesn't make you confuse them. Especially when the corresponding sequence of callouts and actions is practiced and repeated over and over.
All of us have muscle memory for activating the left blinker in our car and pulling the handbrake, but has anyone pulled the handbrake when they wanted to signal left?
i have several passwords i type all the time. sometimes i get them confused and type the wrong one to the wrong prompt. i type them by muscle memory, but i also think about them while typing and i think thoughts like "time to reach up and to the left on the keyboard for this password". I couldn't tell you the letter i'm trying to type, i just know to do that.
not all my passwords are up and to the left, some are down and to the right, but when i type the wrong one into the wrong place, i type it accurately, i'm just not supposed to be typing it.
"time to do that thing i've practiced, reach to the left". shuts two engines off by muscle memory.
> "time to do that thing i've practiced, reach to the left". shuts two engines off by muscle memory.
If that were true, pilots would perform arbitrary motions all the time. Same with car drivers.
Typing something on a keyboard, especially when it's always in the same context, is always essentially the same physical action. The context of a password prompt is the same, the letters on the keyboard feel the same and are right next to each other.
Not comparable to pressing two very different buttons placed far apart, in a context when you'd never ever reach for them.
that makes it less likely, not impossible, we're trying to match against the data we have. I think distracted muscle memory is more likely than suicide and sounding innocent while lying about it
If you shut off the engines a couple of dozen meters above ground shouldn’t every alarm be blaring or there should be some sort of additional lever you have to pull way out of the way to enable shutting off the engine that close to the ground.
If you read through the boeing procedures, if an engine fails just after take off you delay cutting throttle or hitting the cutoff until you have positive climb and pass a certain altitude. Specifically because a mistake here would be so incredibly catastrophic. The following number of steps and verbal cross checks for then shutting down the engine are quite daunting. Not something applicable here, but still interesting to learn about
That’s absolutely applicable here.
It means that an engine cutoff shouldn’t be allowed at all during certain parts of flight. It’s not crazy to think that a design fix would be to prevent those engagements during certain parts of takeoff (a certain window). It’s fly by wire anyway so it could presumably be done programmatically.
MCAS was basically made to prevent user input that would send the plane into a dangerous angle. The computer overrode the inputs. So there’s precedent for something like it.
This is such a funny comment. Of course you have no clue why it is funny. But that makes it all the more funny. Eventually you'll figure it out though.
Would it matter in this case since you would crash either ways. I’m talking about protection in a very specific situation where you make it harder to shut off both engines when you’re very close to the ground.
Three things:-
1) Pilot clearly said I didn't do it.
2) Report talks about the second switch being turned off in a second.
3) Known advisory on switches getting flipped.
If you see these three together, it becomes easy to deduce that based on point 2, switch was not human induced as the actions required take more than a second.
Next the third point, advisory was for this exact scenario which played out, though rare but still it shouldn't have been just an advisory, but more than that.
The switches are right next to each other and have a very short throw[1]- it would definitely be possible to do them in under a second and it looks possible to throw them together.
IMO that looks like a spot that would be pretty difficult to hit accidentally even if the ward failed. You'd have to push them down and the throttles are in the way.
Doesn't mean the switch couldn't have failed in some other way- eg the switch got stuck on the ward but was still able to activate with a half-throw, and spring pressure pushed it back into off during a bump. But switches generally only activate when fully thrown, and failing suddenly at the exact same time is not really what you would expect.
Where do you get this from? You have to pull up the switch with two fingers and move it to the other position and put it back in. This doesn't seem to take more than a second if deliberate.
To me, it points to a Germanwings-style sabotage. And the "I didn't do it" seems to be a lie. Not very confident in it, just the likeliest to me. Though one can ask why not just push the nose down instead. Maybe he thought that's too easy for the other pilot to counteract. The fuel switches are more out-of-mind and more startling to change.
As has been pointed out elsewhere, even if one of the pilots did deliberately move the switches, it's not clear from the reporting so far if that's the same pilot who responded to the question. In other words, it's possible one pilot flipped the switches and then asked the other pilot why he cut off the fuel to misdirect and create more confusion.
Edit: Of course this is all speculation, we don't know if the switches were moved deliberately and if so which pilot did so and which pilot was which in the exchange. More investigation is clearly needed.
In this phase of flight the pilot’s hands should be nowhere near the thrust levers let alone the fuel cutoff switches. There is no way they could accidentally knock them with their hands.
> it becomes easy to deduce that based on point 2, switch was not human induced
This just isn’t correct at all. The evidence isn’t conclusive but if a human operated switch was flipped, and one of the humans present says to the other one hey why did you do that, then Ockham’s razor points to a human flipping the switch.
It’s not the only option, but it’s certainly the most likely.
The advisory was for the lock being disengaged meaning you would still need to manually move it. it wasn't for being moved by factors such as vibrations also If it was from vibration how would a crash impact not move them back to cut off?
Not sure where this is asserted? These aren't complicated mechanisms, it's just a pull lock, right? Pilots flip the switches twice on every flight at startup/shutdown, it's a routine action.
I find these comments very illustrative when taken together- they nicely show how different explanations sound spot on until you read the next one. Inexplicable is one of the great words in the English language
I just want to call out that, whatever the facts of this case, pilot heroism is way more common than pilot murder. This is off the top of my head, so don't quote me on the precise details, I'm probably misremembering some things. But a few of my favorite examples:
- British Airways 5390: An incorrect repair causes the windshield of a plane to be blown out mid flight. A pilot is nearly sucked out. The head flight attendant holds onto his legs to keep him in the plane. The copilot and flight attendant think he is dead, but they keep the situation under control and land the plane.
- United 232: An engine explodes in the tail of an MD-10. Due to rotten luck and weaknesses in the design, it takes out all three of the redundant hydraulic systems, rendering the control surfaces inoperable.
There's a pilot onboard as a passenger who, it just so happens, has read about similar incidents in other aircraft and trained for this scenario on his own initiative. He joins the other pilots in the cockpit and they figure out how to use the engines to establish rudimentary control.
They crash just short of the runway. 112 people die, but 184 people survive.
- Pinnacle 3701: Two pilots mess around with an empty plane. They take it up to it's operational ceiling. While they're goofing off, they don't realize they're losing momentum. They try to correct too late and cannot land safely.
In their last moments they decide to sacrifice any chance they have to survive by not deploying their landing gear. They choose to glide for the maximum distance to avoid hitting houses, rather than maximizing how much impact is absorbed. They do hit a house but no one else is killed.
> British Airways 5390: An incorrect repair causes the windshield of a plane to be blown out mid flight. A pilot is nearly sucked out.
This one is a good illustration of how better design can help prevent accidents or make them less severe.
The error the maintenance people made was that when they replaced the window and the 90 screws that hold it on 84 of the screws they used were were 0.66 mm smaller in diameter than they should have been.
The window on that model plane was fitted from the outside, so the job of the screws was to hold it there against the force of the pressure difference at altitude. The smaller screws were too weak to do that.
If instead the designers of the plane had used plug type windows which are fitted from the inside then the pressure difference at altitude works to hold the window in place. Even with no screws it would be fine at altitude. Instead the job of the screws would be to keep gravity from making the window fall in when the plane is not high enough for the pressure difference to keep it in place.
My vague memory of the Air Emergency episode on this (AKA Air Crash Investigation, Air Disasters, Mayday, and maybe others depending on what country and channel you are watching it on) is that after this accident many aircraft companies switched to mostly using plug windows on new designs.
Aviation is full of those design choices. Similar to how a multi-engine propeller plane will use oil pressure to keep the props in the flying angle, which means that when oil pressure is lost (catastrophic engine failure) it will feather giving the other engine the best chances of keeping the plane flying with the least amount of drag. While on a single-engine plane it's installed exactly opposite, in case of oil pressure loss the prop goes to fine pitch giving you the best hope of creating some trust in case the engine may still be working.
Most of these things were figured out over 100 years of carefully analysing accidents and near accidents to continuously improve safety.
Anyone who does on-call should look into aviation disasters. Crew resource management, the aviate-navigate-communicate loop, it's all very applicable. ('WalterBright is an excellent source of commentary on applying lessons from the airline industry to software.)
But I did burn out on Mentour Pilot after a while, I just had my fill of tragedy.
A long time ago I had a colleague turn me on to Sidney Dekker’s “Drift Into Failure”, which in many ways covers system design taking into account the “human” element. You could think of it as the “realists” approach to system safety.
At the time we operated some industry specific, but national scale, critical systems and were discussing the balance of the crucial business importance of agility and rapid release cycles (in our industry) against system fragility and reliability.
Turns out (and I take no credit for the underlying architecture of this specific system, though I’ve been a strong advocate for this model of operating) if you design systems around humans who can rapidly identify and diagnose what has failed, and what the up stream and down stream impacts are, and you make these failures predictable in their scope and nature, and the recovery method simple, with a solid technical operations group you can limit the mean-time-to-resolution of incidents to <60s without having to invest significant development effort into software that provides automated system recovery.
The issue with both methods (human or technical recovery) is that both are dependent on maintaining an organizational culture that fosters a deep understanding of how the system fails, and what the various predictable upstream and downstream impacts are. The more you permit the culture to decay the more you increase the likelihood that an outage will go from benign and “normal” to absolutely catastrophic and potentially company ending.
In my experience companies who operate under this model eventually sacrifice the flexibility of rapid deployment for an environment where no failure is acceptable, largely because of an lack of appreciation for how much of the system’s design is dependent on an expectation of the fostering of the “appropriate” human element.
(Which leads to further discussion about absolutely critical systems like aviation or nuclear where you absolutely cannot accept catastrophic failure because it results in loss of life)
Extremely long story short, I completely agree. Aviation (more accurately aerospace) disasters, nuclear disasters, medical failures (typically emergency care or surgical), power generation, and the military (especially aircraft carrier flight decks) are all phenomenal areas to look for examples of how systems can be designed to account for where people may fail in the critical path.
Something I love about Mentour pilot is that he’s started doing videos on incidents where there was a near miss but no tragedy. Just as much to learn but without the ghoulish rubbernecking aspect.
In the particular case of his channel's subject matter, I actually kind of like the dramatic cliffhanger effect that (un)intentionally heightens the narrative's tension, since his video is telling a story. Compare to doing that for informational videos where there's no need for manufactured drama.
- Pilot calculated incorrect fuel due to metric/imperial unit mixup, and ran out of fuel midair.
- Said pilot performed an impossible glider-sideslip maneuver to rapidly bleed airspeed just-in-time for an emergency landing at an abandoned airfield, having to completely rely on eyeballing the approach.
It was a series of events and failures rather than simply “pilot calculated incorrect”. And it was a bit more nuanced than metric/imperial conversion.
Via wiki (but accident section is more detailed):
“ The accident was caused by a series of issues, starting with a failed fuel-quantity indicator sensor (FQIS). These had high failure rates in the 767, and the only available replacement was also nonfunctional. The problem was logged, but later, the maintenance crew misunderstood the problem and turned off the backup FQIS. This required the volume of fuel to be manually measured using a dripstick. The navigational computer required the fuel to be entered in kilograms; however, an incorrect conversion from volume to mass was applied, which led the pilots and ground crew to agree that it was carrying enough fuel for the remaining trip. ”
If you're focused on whether or not the pilot cares (or is even alive), you've lost the plot. The point is to keep passengers alive regardless of the pilot.
There's no real point to considering what happens if the pilot wants to murder people on board. Of course they will succeed....
The thing is, people always want something to be done. And politicians want to do something. No matter what kind of action it is, someone knifed a kid on the street, we must ban knives of a certain length. A pilot downs a plane while the other leaves the cockpit - we must mandate two pilots always present. Someone hides explosives in his shoe - we must X-ray all shoes of all passengers forever. Etc.
The human brain can't take the idea that yeah an exceedingly rare thing happened and we're not going to do anything, because rare things do happen sometimes. And the medicine can be worse than the disease. We just accept that yeah, despite best efforts, some pilots will be hostile for whatever mental reasons. Not saying that is what happened in this case, but just saying that IF that happened.
We need more tradeoff thinking, instead of do something! thinking.
The NYTimes states that there was an advisory on the switches but that the FAA had not deemed them unsafe. It also states that on this plane the switches were changed in 2023.
Each of the fuel switches on the 787 is equipped with a locking mechanism that is supposed to prevent accidental movement, experts said. To turn the fuel supply on, the switch must be pulled outward and then moved to a “RUN” position, where it is released and settles back into a locked position. To turn the fuel supply off, the switch must be pulled outward again, moved to the “CUTOFF” position and then released again.
Or they could be inadvertently flipped if the "locking" version was not installed:
(see the avherald link):
>>India's media report that the investigation is NOT focussing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure. Service Bulletins by Boeing issued in year 2018 recommending to upgrade the fuel switches to locked versions to prevent inadvertent flip of the switches, as well as the FAA/GE issued Service Bulletin FAA-2021-0273-0013 Attachment 2 relating to loss of control issue (also see above) were NOT implemented by Air India.
> Recommendations
The FAA recommends that all owners and operators of the affected airplanes incorporate the
following actions at the earliest opportunity:
1) Inspect the locking feature of the fuel control switch to ensure its engagement. While the
airplane is on the ground, check whether the fuel control switch can be moved between the
two positions without lifting up the switch. If the switch can be moved without lifting it up,
the locking feature has been disengaged and the switch should be replaced at the earliest
opportunity.
2) For Boeing Model 737-700, -700C, -800, and -900ER series airplanes and Boeing Model 737-
8 and -9 airplanes delivered with a fuel control switch having P/N 766AT613-3D: Replace the
fuel control switch with a switch having P/N 766AT614-3D, which includes an improved
locking feature.
> On Jul 12th 2025 (UTC) India's media report that the investigation is NOT focussing on a human action causing the fuel switches to appear in the CUTOFF position, but on a system failure. Service Bulletins by Boeing issued in year 2018 recommending to upgrade the fuel switches to locked versions to prevent inadvertent flip of the switches, as well as the FAA/GE issued Service Bulletin FAA-2021-0273-0013 Attachment 2 relating to loss of control issue (also see above) were NOT implemented by Air India. The stated MN4 computer with faulty soldering, that might weaken and lose contact due to the thermal stress after a number of cycles, interprets data and commands fuel metering valves - with the lost contact attaching the MN4 processor to the EEC intermittent electrical contact, loss of signal processing and engine control faults can occur. The SB writes under conditions for the SB: "An LOTC (Loss Of Thrust Control) event has occurred due to an EEC MN4 microprocessor solder ball failure." According to discussions in the industry it may be possible with the number of cycles VT-ANB had already completed, the solder balls were weakened sufficiently to detach the MN4 from the EEC momentarily due to loads during the takeoff rotation leading to the loss of control of thrust and shut down of the engines.
Still quite early in the investigation, and so many things to consider. I don't know why online communities have been so quick to gravitate towards the murder/suicide theory. I thought aviation enthusiasts of all people would want to keep an open mind until every other possibility is ruled out, however minuscule it might seem.
My concern would be that the investigation in this case is more likely to be biased towards a system failure. Disgracing a major flag carrier is something very few regulars have the independence and courage to get away with.
> I don't know why online communities have been so quick to gravitate towards the murder/suicide theory.
Because the hardware failure theories seem preposterously far-fetched and require an unnecessary multiplication of deities.
Your ghost in the machine needs to be “just so” so that it can cause both switches to be read in “cutoff” nearly simultaneously. Then, 10 seconds later one of the switches needs to be read in “run”, then 4 seconds after that the second one needs to read “run”. You also need to explain why there have been zero single engine failures of this type before this double failure.
The ghost also needs to explain why one pilot asked the other “why did you cutoff?” instead of something like “what happened to the engines?” (which is the more natural response, unless you already know the switches are in cutoff).
Most importantly it's extremely problematic that BBC is pushing the pilot error angle subtly! This is a preliminary report! No news organization should spread opinion pieces based on this.
Somehow it feels like Boeing paid BBC to shift the narrative.
We should all wait for the final report. Pilot error or Machine fault, either way it's a huge tragedy.
Where did you see that? You say subtle. What does that mean?
It's a fact that there are no recommendations to manufacturers or airlines yet. If they had found anything seriously suspicious they would already issue recommendations as soon as possible, not just in the final report, not even just at the prelim report, but as fast as possible. Grounding planes, forcing maintenance etc. That has not happened.
It's easy to fall in the other direction and jump on the Boeing hate bandwagon. It's become a trendy thing online.
The report contains significant evidence that one of the pilots switched off the engines.
It doesn’t rule out other options, and it doesn’t explain why they might have done that or if it was inadvertent but it’s still new information, and presenting new important information is what the news is for.
> The EGT was observed to be rising for both engines indicating relight. Engine 1’s 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.
I know it's probably not worth the hazmat tradeoff for such a rare event, but the F-16 has an EPU powered by hydrazine that can spool up in about a second.
The F-16 EPU is to keep the flight controls powered so the plane doesn't immediately become uncontrollable following engine failure. The EPU doesn't provide thrust of any kind.
The 787 and nearly every other commercial aircraft with powered flight controls [1] (fly-by-wire or traditional) has emergency power available via RAT and/or APU, and any fly-by-wire aircraft has batteries to keep the flight control computers running through engine failure to power supply being restored by the RAT and/or APU. Due to its unusually high use of electrical systems, the 787 has particularly large lithium batteries for these cases. There is no need for an additional EPU because the emergency systems already work fine (and did their jobs as expected in this case). You just can't recover from loss of nearly all engine thrust at that phase of takeoff. [2]
1. The notable exceptions to having a RAT for emergency flight controls are the 737 and 747 variants prior to the 747-8. In the 747 case, the four engines would provide sufficient hydraulic power while windmilling in flight and thus no additional RAT would be necessary. The 737 has complete mechanical reversion for critical flight controls, and so can be flown without power of any kind. There is sufficient battery power to keep backup instruments running for beyond the maximum glide time from altitude - at which point the aircraft will have "landed" one way or another.
2. There is only one exception of a certified passenger aircraft with a system for separate emergency thrust. Mexicana briefly operated a special version of the early 727 which would be fitted with rocket assist boosters for use on particularly hot days to ensure that single-engine-out climb performance met certification criteria. Mexicana operated out of particularly "hot and high" airports like Mexico City, which significantly degrade aircraft performance. On the worst summer days, the performance degradation would have been severe enough that the maximum allowable passenger/baggage/fuel load would have been uneconomical without the margin provided by the emergency rockets. I'm not aware of them ever being used on a "real" flight emergency outside of the testing process, and I think any similar design today would face a much higher bar to reach certification.
Wouldn't be able to save a fully-loaded 787 in low & slow conditions because the area of canopies needed to deploy would be several acres. And they'd add several tonnes.
The Cirrus system is deployed by rockets, allowing it to function at a very low altitude. They say that you should deploy it no matter what altitude you are at, and it will add at least some friction. The system has a very impressive track record.
However, at this altitude, with an airplane this heavy, you might have to put the rockets on the plane to decelerate enough to save lives.
This report is outlining the known facts of the flight at present. The main one being the movement of the fuel switches to the off position did occur a few seconds after take-off, almost certainly by one of the pilots. And this was the primary cause of the crash. However, blame has not been apportioned and the reason for why is not known.
I recall something similar to this happened in the USA in 2023. An off-duty pilot in the cockpit tried to pull that fuel shut-off handle (edit: I'm informed it's a different fuel shut-off mechanism), but was overpowered by the other two:
> "Both pilots then saw Emerson grab on to the red fire handles, also known as the “T-handles,” which are used to extinguish engine fires and shut off all fuel to the engines, potentially turning the plane into a glider, the pilots told federal investigators."
> "“If the T-handle is fully deployed, a valve in the wing closes to shut off fuel to the engine. In this case, the quick reaction of our crew to reset the T-handles ensured engine power was not lost,” Alaska Airlines said in a statement."
> "One pilot struggled with Emerson for about 25 or 30 seconds before the off-duty pilot “quickly settled down,” according to the complaint."
That's not the same one, that's the big red FIRE ones on the overhead panel. They're not reversible and are under a plastic cover. As far as I know these ones are. They're also used to just switch them off at the end of a flight which can of course be reversed. But I guess in this case there wasn't enough time. They only had 30 seconds.
Why didn't they turn them back on then? Or does it take too long to spin up again even if they are still spooling down? This is one of the worst possible moments for this to happen of course. Low speed, low altitude, lots of drag...
They did, about 10 seconds later (which is both incredibly short and an eternity). But the engines almost immediately start losing thrust and it takes them much more time to restart. At the end of the flight, FDR records that one engine was gaining thrust, and the other was attempting to spin up, but it was too late and they didn't have enough glide time for both to gain enough thrust to climb.
I'm completely ignorant about this matter, but why is it even possible to cut off fuel while taking off? Shouldn't there be a control that completely disables this? Is there actually a situation where cutting off both engines could be necessary and wouldn't lead to a catastrophe?
The general principle of aircraft control is that the pilot has the final say on how it is operated, not the designer, because you never know when you will need to take extraordinary measures. And the pilot generally prefers to return to the ground safely.
I'm assuming fuel being cut off is salvageable if not in the middle of a densely populated city, especially if above a plain or water. So it could be the favorable option in case of an engine fire.
Also, such complexity would introduce additional points of failure - as a sister comment mentions, a faulty altimeter (or whatever sensor) could prevent you from cutting off fuel when you need to.
> if not in the middle of a densely populated city, especially if above a plain or water
What is on the ground below does not matter at that point - how far above that ground you are is what is important. More altitude is more time.
This flight was less than 200 meters up in the air. Sully's flight that you probably remember, that made a successful emergency landing on the river, was about 860 meters high, giving them much more time - about 3.5 minutes of glide time, vs. 32 seconds in the air, total, for the Air India flight.
Pretty sure nearly all runbooks have you first move the thrust lever to idle before cutting off fuel. That suggests you shouldn't be able to cut fuel independently of the throttle.
Sometimes? If you have enough altitude to trade for speed then after the cutoff you could glide to a hypothetical miraculously-placed runway right in front of you, vs. having fire quickly consume the entire plane if you don't cutoff..
> 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. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off.
So the fuel supply was cut off intentionally. The switches in question are also built so they cannot be triggered accidentally, they need to be unlocked first by pulling them out.
> In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so.
And both pilots deny doing it.
It's difficult to conclude anything other than murder-suicide.
well hold your horses there... from the FAA in their 2019 report linked above:
> The Boeing Company (Boeing) received reports from operators of Model 737 airplanes that the fuel control switches were installed with the locking feature disengaged. The fuel control switches (or engine start switches) are installed on the control stand in the flight deck and used by the pilot to supply or cutoff fuel to the engines. The fuel control switch has a locking feature to prevent inadvertent operation that could result in unintended switch movement between the fuel supply and fuel cutoff positions. In order to move the switch from one position to the other under the condition where the locking feature is engaged, it is necessary for the pilot to lift the switch up while transitioning the switch position. If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation. Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown. Boeing informed the FAA that the fuel control switch design, including the locking feature, is similar on various Boeing airplane models. The table below identifies the affected airplane models and related part numbers (P/Ns) of the fuel control switch, which is manufactured by Honeywell.
> If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation. Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown
Both of these extremely-experienced pilots say that there was near zero chance that the fuel switches were unintentionally moved. They were switched off within one second of each other, which rules out most failure scenarios.
If it was an issue with the switches, we also would have seen an air worthiness directive being issued. But they didn’t, because this was a mass murder.
Maybe as the PIC was guarding the lower end of the throttle he rested the rest of his hand on the panel cover below the throttle and, while pushing forward on the throttle, let the side of his hand slide down right onto the switches, the likeliness of which would have been exacerbated by a rough runway or a large bump. It's unlikely the left and right part of his hand would have contacted the cutoff switches at the same time, hence the delay between the two switches being actuated. Of course this relies on the safety locks not working properly, which is something that hand been reported.
Nope. First of all, the FO was the “pilot flying” and thusly controls the throttle. The fuel shutoffs are on the left side, well clear of the range of motion throttle operation for the right seat.
If the Captain were controlling throttles, it for some reason he could contort his wrist to accidentally open the red cutoff switch guards, the switches themselves move in the opposite direction of the pivot of the switch guard. And to have that happen to both switches — one second apart. That would be astronomically (not to mention anatomically) improbable: you can’t have your hand on the throttle and also be dragging your arm on the switches unless the pilot has an extra elbow.
Further more, the 787 has auto throttles, at takeoff the pilot advances the throttles to N1, then all the way through climb out the auto throttles control the throttle unless manually disengaged.
Also a “bumpy runway” wouldn’t do anything because if those switches were activated on the roll out, the engines would shut down almost immediately: that’s the point of those switches to kill fuel flow immediately not minutes later.
And no there isn’t a report of the safety locks not working properly on the 787. The report to which you are referring was in 2018 and that was an issue with a very few 737 switches that were improperly installed. The switches didn’t fail after use, they were bad at install time. Exceedingly unlikely that a 787 was flying for 12 years with faulty switches. (Notwithstanding the fact they they are completely different part numbers.)
The 787 that crashed had been in service since 2013 which means if that were a problem in that plane, however unlikely, with hundreds of thousands of flight hours, inspections, and the 2018 Airworthiness Bulletin — that problem would have been detected and corrected years ago.
The issue with the 737 MAX became evident within months of the plane's launch. By contrast, the Dreamliner has accumulated over a decade of flying history across over 1000 aircraft with precisely zero fatal accidents.
The fact that the pilots denied that they had shut the switch (one asking the other why they had done so and the other denying it), and that they restarted the engines should be taken into account. Ok, murder suicide is definitely on the table but I would want to see some other reasons for believing that this is so.
Sorry to nitpick, but for a good Bayesian, absence if evidence is evidence of absence. If you want the aphorism to be technically correct, you should say "absence of proof is not proof of absence".
A note on the terminology: "evidence" is a piece of data that suggests a conclusion, while not being conclusive by itself. Whereas "proof" is a piece of data that is conclusive by itself.
please. pilot puts everyone to sleep but himself, turns everything off, then does a flyby of his hometown and then puts himself to sleep? the only one more obvious is the german one.
It feels quite uncomfortable to me. I remember using this exact example of why the changes after the German wings crash wouldn't prevent a murder suicide in the future.
I'm not disagreeing with you I think this was manually done
But here's the thing a "near zero chance" when we are talking about an actual event changes the math
Maybe there's a combination of vibration and manufacturing defect or assembly fault or "hammer this until it works" that can cause the switches to flip. Very unlikely? Yes. Still close to 0% but much more likely in the scenario of an accident
Of course AAIB/NTSB etc didn't have any time to investigate the mechanical aspects of this failure
So yeah it was probably done intentionally but the "switches turning off by themselves" should not be excluded
We could also suggest that aliens in the cockpit did it — about the same probability. Two switches, on independent circuits, both failing within one second of each other in the exact same way?
My buddy says the same, he’s a 787 captain for United. Essentially impossible to accidentally turn off those switches. My buddy isn’t “evidence” of course, but actual airline captains are all saying similar things.
A few years ago I was working at a company that used a robotic arm when an accident occurred. The robot was powered off for maintenance but suddenly turned on, pinned a worker's arm, and threw him against a wall. His arm had numerous fractures and he had severe head injuries but survived.
The other worker in the building was in absolute shambles and couldn't understand what had happened. The CCTV footage was then checked and showed that worker looking at the other while reaching for the power switch and turning on the machine. The switch was not locked out and tagged out, but it was the only switch like it on the whole panel, large and required significant force to turn. No way to accidentally bump it, and the video showed him clearly turning the handle.
He was obviously fired, but no criminal charges were ever brought against him. He had no plausible motive for wanting the other man dead, was severely distraught over the incident. It was simultaneously obvious that he had turned the lever deliberately and had not meant to turn the leaver. A near-lethal combination of muscle memory and a confusion caused the accident. If the lever had been locked and tagged out, that probably would have interrupted his muscle memory and prevented the accident, but it wasn't.
Point is, something can be simultaneously impossible to do inadvertently, but still done mistakenly. A switch designed to never be accidentally bumped, to require specific motions to move it, can still be switched by somebody making a mistake.
Perhaps there are more qualifying statements that you meant to include? The certification and type rating requirements certainly differ between agencies, but in terms of raw number of flight hours it’s easy to find that this statement is false.
These switches are operated at startup and shutdown. So pretty much daily. By pilots and likely maintenance crews. Such a defect with not to unnoticed for long
What is "01 second" as quoted above? If it's 1 second, you could possibly conclude that it was intentional. If it's 0.1 second you might think it was an accident and the lock was disengaged.
There is no electronic lock as far as I know, as many people seem to assume. It's a mechanical notch that you have to physically pull the switch past to operate it. The lock failures described in the air worthiness directive was about this mechanical stop or notch not being installed.
Many systems log samples at an intervale of one sample per second. I could easily envision a transition event where a bump or brush of something sufficiently toggles one switch and then a fraction of a second later the other.
You don’t inadvertently turn off both switches. The linked SAIB was in 2018 and addresses faulty installations, not a failure after use. And preflight over thousands of flights would have detected if the switches had a failed locking mechanism. And for both to fail at once? Practically impossible. Also the recommended inspection — that was almost 7 years ago. If a major airline didn’t comply with the SAIB, that’s on them, not Boeing. There hasn’t been a single reported instance of fuel switches being accidentally switched off on any Boeing airliner — in 320 million flight hours over the past 10 years.
The switches are spring-loaded, notched in place, and have a rubber knob on the top. A pilot must squeeze the knob, remove the switch from its ON notch, press the switch, click it into the OFF notch, then release the knob.
They were moved back to the run position 10 seconds after being switched off, and the engines were in the very early stages of restarting by the time of the crash. It was too late.
More like 30 seconds. Just throttling an already running engine up from idle (which is quite a bit above zero throttle in most respects) takes seconds.
at least one of the pilots did. according to the preliminary report, the switches were only in the cutoff position for 10 seconds before being switched back to the run position and the engines started to spin up again
The only affected models were 737s with the 766AT613-3D fuel control switch. The bulletin recommended that other models be inspected and any defects reported. It's unclear if any 787s were discovered to have the issue. Also the preliminary report mentions that the switches were replaced in 2019 and 2023, after the 2018 bulletin.
still, it at least shows that there's been issues with the locking mechanism in the past. inadvertently bumping something that was assumed to be locked is a simpler theory; i find it hard to believe that a murder suicider would take this route, when the china nosedive option is easier, faster, and has a higher chance of success.
The preliminary report says the switches were triggered a second apart, so it would have to have been faulty switches and two inadvertent bumps. That seems unlikely to me.
Within a second apart. If I read the report right. The time resolution of the recorder?
And yes, it does sound like it was probably intentional. I would still like to see an engineering review of the switch system. Are they normally open or normally closed, In the end the switch instructs the FADEC to cut the fuel, but where does the wiring go in the meantime? what software is in the path? would the repair done before the flight be in that area?(pilot defect report for message STABS POS XCDR), and perhaps compromised the wires?
It's interesting to try to imagine a device that would prevent that, without causing more issues.
My preliminary idea is a "fuel bladder" for take-off that inflates with enough fuel to get the plane to a recoverable altitude, maybe a few thousand feet?
> Again, it’s probably pointless but it’s an interesting thought exercise.
Coming up with ad-hoc solutions is easy, especially the less you know about a complex system and its constraints. I'd say it's not an interesting exercise unless you consider why a solution might not exist already, and what its trade-offs and failure modes are. Otherwise, all you're doing is throwing pudding against a wall, which can of course be fun.
That’s the whole fun part - come up with an “obvious” solution and the try to figure out the problems or risks it would cause.
For example, an obvious solution is that the switch can't be changed from "RUN" to "CUTOFF" when the throttle isn't at idle - this could be done with a mechanical detent because they're right next to each other. Simple!
But now you've introduced additional failure modes - throttle sticks wide open and the engine is vibrating and needs to be shut down - so maybe you make it that the shutdown switch can work for ONE engine at any throttle position, but if TWO get turned off, both throttles have to be off, but that introduces ...
It’s a pointless exercise though - if one of the pilots wants to crash the plane, there’s almost nothing that can possibly be done. Only if someone can physically restrain them and remove them from the controls.
There’s always going to be many ways they could crash the plane, such a feature wouldn’t help. The pilots are the only people you can’t avoid fully trusting on the plane.
It's only pointless if we assume crashing was the intended result of the pilot. If the switches failed, or the pilot activated the switches by mistake, it's worth considering options for handling the inputs.
There's a balance of accidents to be found, I think. There are likely cases where fuel does need to be cut off to both engines, and preventing that would lead to accidents that might have been recoverable. This case shows that cutting off fuel to both engines during takeoff is likely unrecoverable. There have been cases where fuel is cutoff to the wrong engine, leading to accidents. Status quo might be the right answer, too.
So basically we need software that can 100% autonomously fly a plane. Software that is extremely reliable and trustworthy, basically. Software with multiple fallback options. Multiple AI agents verifying every action this software takes. Plus, ground-based teams monitoring the agents and the autonomous flight software.
Or you simply interlock the engine cutoff with the thrust lever position, any position other than idle prevents shutdown. This all goes through the flight computers already.
If there’s a fire or similar problem the fire handles will cut off fuel without the normal shutdown procedure, but the normal switches only need to be used at idle thrust.
I wonder if Airbus has this logic, since their philosophy is to override the pilot commands if they’d endanger the aircraft (which has its own issues of course) where’s Boeing will alert the pilots and still perform the action. I don’t have access to that information.
According to AI, Airbus places these switches on the overhead panel, so that alone would make it harder to inadvertently move them. Apparently, Airbus "protections do not extend to mechanical or FADEC‑controlled systems like the engine‑fuel shutoff valves. If you deliberately pull and flip the ENG MASTER lever to OFF, the FADEC will immediately close the LP and HP fuel valves and the engine will flame out. If you then return the lever to RUN (and you meet relight conditions), it will automatically relight."
As another commenter said the Airbus engine start/stop controls are located behind the thrust levers, and according to the A350 operations manual which I got my hands on there are two conditions required for the FADEC to command engine shut down: Run switch to off, thrust lever to idle.
So if that's correct on an Airbus aircraft you can't just switch off the engines when they're commanded to produce thrust. This also seems to be backed up by the difference in the guards for those controls in the Airbus cockpits.
And yet the preliminary report for the incident in question includes reference to that bulletin, indicates that the switches in the accident aircraft were of a very similar design and subject to advisory inspections:
"The FAA issued Special Airworthiness Information Bulletin (SAIB ) No. NM -18-33 on
December 17, 2018, regarding the potential disengagement ofthe fuel control switch locking
feature. This SAIB was issued based on reports from operators of Model 737 airplanes that
the fuel control switches were installed with the locking feature disengaged. The airworthiness
concern was not considered an unsafe condition that would warrant airworthiness directive
(AD) by the FAA. The fuel control switch design , including the locking feature, is similar on
various Boeing airplane models including part number 4TL837-3D which is fitted in B787-8
aircraft VT-ANB. As per the information from Air India, the suggested inspections were not
carried out asthe SAIB was advisory and not mandatory. The scrutiny ofmaintenance records
revealed that the throttle control module was replaced on VT-ANB in 2019 and 2023.
However, the reason for the replacement was not linked to the fuel control switch. There has
been no defect reported pertaining to the fuel control switch since 2023 on VT-ANB."
So while I agree that this being the cause sounds unlikely, referencing the switch issue is something relevant enough for the report itself.
> It's difficult to conclude anything other than murder-suicide.
You're leaping into the minds of others and drawing conclusions of their intent. One of them moved the levers. It could've been an unplanned reaction, a terrible mistake, or it could've been intentional. We may never know the intention even with a comprehensive and complete investigation. To claim otherwise is arrogance.
The car equivalent is being on a highway and "mistakenly" pulling the hand brakes, except that there are 2 hand brakes and you need to first unlock both of them.
That's very hard to do by panic and mistake, if not impossible by design.
On pprune there is a professional pilot that says they had multiple instances of inadverent switching off fuel switches. They do it every startup, shutdown and training captains (the captain on this flight was pilot not flying, he had >10k hours) do it all the time in the sim to trigger engine out scenario during training
Bad analogy because pilots are trained and rehearse and practice memory items until they are instinctual.
> impossible by design.
Deflecting that the human is the weakest part of the system. One or other may have panicked and made a mistake, made a mistake unintentionally, went crazy and doomed the flight, or intentionally doomed the flight for some socioeconomic reasons. These are speculative possibilities that we don't know yet, and may never know; we only know what has definitely happened from the evidence per the investigation. It's standing way out over one's feet to declare from an armchair that it was "definitely" X or Y before the investigation is complete.
It was done. Yes. There is no way to determine from the evidence why it was done, how much conscious or not thought was put into it, or the thought process behind it.
> One of them moved the levers. It could've been an unplanned reaction, a terrible mistake, or it could've been intentional.
Fuel levers are designed to only be moved deliberately; they cannot be mistaken for something else by a professional pilot. It's literally their job to know where these buttons are, what they do, and when to (not) push them.
It's not arrogance to assume the most likely conclusion is true, despite how uncomfortable that outcome may be.
Pilot are trained until actions are instinctual and certain memory items are almost unconscious. But pilots are still people and people are fallible and make mistakes, and sometimes act unreasonably. Intent cannot be determined without clear evidence or statements because that's now how thoughts locked away in people's minds work.
> It's not arrogance to assume the most likely conclusion is true
You don't know this. This is beyond the capability to know and is therefore pure speculation. That is the definition of arrogance.
> sometimes act unreasonably. Intent cannot be determined without clear evidence or statements because that's now how thoughts locked away in people's minds work.
By this logic it would be impossible to ever find anyone guilty of murder (or any other nefarious action) with intent unless they explicitly state that it was in fact their intent.
Obviously this is not how justice works anywhere, because at some point you have to assume that the overwhelmingly most likely reason for doing an action was the true reason.
If someone pulls out a gun, cock it, aim it at someone and pull the trigger, killing the other person, should we hold off any judgement because they might have done it purely mechanically while in their head thinking about the lasagna they are going to cook tonight and not realizing what they were doing ?
The fuel cut off switches have a unique design, texture and sequence of action that need to be taken to actuate them, they don’t behave like any other switch.
Pilot are also absolutely not trained to engage with those particular switches until it’s instinctual.
Courts do not seek to establish the truth. They aim for a reasonable balance between false positives (innocents convicted of crimes they didn't commit) and false negatives (criminals allowed to go free). In practice, the false positive rate is probably around 5%, and innocents go to prison all the time.
Air accident investigations mostly deal with one-in-a-billion freak occurrences. Commercial aviation so safe and reliable that major accidents rarely happen without a truly extraordinary cause.
Yeah and the other pilot flipped the switches back on and one of the engines started spooling up but it was too late.
Murder-suicide looks like the likely conclusion, given that flipping the cutoff switches requires a very deliberate action. That said, it's not entirely impossible that due to stress or fatigue the pilot had some kind of mental lapse and post-flight muscle memory (of shutting off the engines) kicked in when the aircraft lifted off.
The report shows 0 flight hours during the prior 24 hours for both pilots, and 7 hours and 6 hours each for the previous 7 days. It seems they were both fresh pilots for this flight.
0.1% of airline pilots fly intoxicated, and probably many more fly hangover which is an undetectable condition.
There is speculation that in the Air France flight 447 that crashed into the ocean en route to Paris, one or the pilots only had 1h of rest because of partying the night before. Of course it’s all speculative, and however unlikely it is, eventually it’s bound to happen that we get pilots with poor mental clarity in charge of large Boeings with hundreds of lives on board. Unfortunately it only takes one lapse of judgement to compromise the flight profile of a large airliner, even if corrected after a few seconds.
At some point I think we need to accept more control from automation. The model where ultimate authority reverts to a single input is a cop out. That could be pilot input, sensor input or even direction from ATC. They will all provide false data on occasions. When that data contradicts 99% of the other data then the safest option is to ignore it. And that doesn't just mean with compromised humans but with normal human weakness. Fully understanding the aircraft, its state, its systems and the minds of its crew is impossible.
In this case I wonder if the fuel cut off switches could be replaced by buttons for particular situations. Have an engine fire button or a shut down whilst on the ground button. Let the pilot provide input on state and let the automation decide what to do with that. Obviously this is not a solution to suicidal or murderous behaviour. But it could be a solution to all the low probability edge cases.
However, the only relevant evidence that exists suggests they had enough rest. You don't build verdicts on suppositions, you build them on proven facts.
This does not guarantee you will reach the truth, but it's miles better than admitting every baseless hypothesis that comes up.
> So the fuel supply was cut off intentionally. The switches in question are also built so they cannot be triggered accidentally
FAA issued a Special Airworthiness Information Bulletin SAIB NM-18-33 in 2018 warning that on several Boeing models including the 787 the locking mechanism of the fuel switches could be inoperative.
I once worked with a software engineer who would do things and then bald face lie about it. This reminds me of that person.
Me: “The build is breaking right after you checked in. Why did you do that?”
Him:”I did not do so.”
Me: “The commit shows it as you. And when I rolled back everything builds.”
Him:”It must have been someone else.”
I’ve worked with some chronic liars. They would deny reality no matter how much evidence you had.
The weirdest thing was how often it worked for them. In each case their lying eventually caught up with them, but in some cases they’d get away with lying for years.
It’s amazing how often someone would have clear evidence against what they were saying, but the people in positions of authority just wanted to de-escalate the situation and move on. They could turn anything into an ambiguous he-said she-said situation, possibly make a scene, and then make everyone so tired of the drama that they just wanted to move on.
i worked in many companies but I always remember one , where during a public chat in the middle of an open office the programmer next to me (who was always conniving but I just ignored it ), said incorrectly something akin to " yes I know all about that source control its... based on locking " , the whole point was that although locking technically occurs, the SC would allow different coders to work on it at the same time. The non technical manager said correctly, "no the whole point is that the codebase isnt locked", to which the programmer replied " yeah thats what I mean".
In that moment I realised he was just bare faced lying right infront of everyone, about a technical subject, only HE should be the expert in, and to this day I am perplexed why his contract kept being renewed.
Eventually I was let go ( he possibly suggested I be let go ) for an incident that was unrelated to me.
This is all fine, but i learnt 5 years on he was still being paid a top 1% salary at the same company.
I promise the point isnt that I am jealous, its that this guy, who was a sub par coder and liar, somehow managed to keep his job whilst everyone else lost theirs and earnt untold amount in England ( where salaries are always low).
My goodness - I just remembered he was found by police driving a vehicle seemingly under the influence on a motorway, work found out after the police called them, and somehow he turned up the next day at work , lied about it, and STILL kept his job.
I am only mentioning this guy , because he was NOT a nepotist hire, he was just some guy who would lie and somehow people were ok with it. I still think of him often and wish I could have learnt more from his abilities just out of interest.
> 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. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off.
> As per the EAFR, the Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN at about 08:08:52 UTC.
Damn. That's pretty quick to diagnose and take action.
Boeing's probably gonna have a big sigh of relief over this one.
> Boeing's probably gonna have a big sigh of relief over this one.
The 787 is 15 years old, and this particular plane was 10 years old. It always seemed unlikely to be a major, new issue. My money was actually on maintenance.
While unlikely, there have been issues before that took decades to surface (e.g. Aloha Airlines where a 737 manufactured more than a decade earlier became a cabriolet due to Boeing underestimating sea water corrosion and short flight cycles), or the 737 rudder issues where the planes were also 10+ years old.
Does the Flight Data Recorder consider the physical position of the fuel switches or does it get the information from some fly-by-wire part that could be buggy?
The conversation would suggest that the switches were in CUTOFF position, but there is also a display that summarizes the engine status.
There is no conversation that mentions flipping the switch to RUN again.
EDIT: Why is there no Cockpit Video Recorder? The days of limited storage are over.
I've had discussions on HN with people who insisted that having a video camera always pointed out the control tower at the runway was some sort of impossibility. Despite every 7-11 having such a system.
This would leave accident investigators with a lot of work to do to try to figure out how a collision happened.
Airlines are decades behind on tech. You can get satellite internet almost anywhere on the planet and GPS can give you ten-foot accurate positioning, but we've still _lost_ planes because we haven't mandated a system that sends the realtime position of the plane over the satellite internet. The days of limited storage are still going strong in the industry.
There are reasons they don’t. This is a deceptively difficult problem
Cost is a big one (satellite data is still quite a bit more expensive than you think, especially with many stations)
And by stations, I mean aircraft. There are a TON. Current constellations probably wouldn’t even be able to handle half the current aircraft transmitting all at once. Bandwidth, in the physical sense, becomes a limiting factor
Coverage (different constellations have different coverage, which means planes would not have transmit guarantees depending on flight path). So you’d have huge gaps anyways
There have been alternative solutions posed, some of which are advancing forward. For example, GPS aware ELTs that only transmit below certain altitudes. But even that has flaws
Anyways I think we’ll see it in the next decade or two, but don’t hold your breath
There's somewhere around 15 thousand relevant planes in the air at any time.
If you sent two updates a minute over Iridium, using their 25 byte message plan, you'd be looking at a megabyte per minute for the entire planet. That's such a tiny fraction of what that single constellation can do.
Most airplanes regularly crossing oceans already do have satcom.
The cost of hardware and additional fuel consumption due to drag aren’t nothing, but the data used itself is essentially a rounding error. (Iridium for example has tiny antennas, and SBD data costs about a dollar per kilobyte, and position data is tiny.)
Of course, that’s all little help when a pilot acts adversarial; on MH370, the breakers for both satcom and transponder were likely pulled, for example.
Yep. Inmarsat has this data for most of the world widebody fleet, and had it for MH370... except when transmission stopped. It's not publicly shared information, because that's what the ADS-B transponder they're all equipped with is for...
> Cost is a big one (satellite data is still quite a bit more expensive than you think, especially with many stations)
That’s nonsense. Even when I’m flying right over the north pole my airline will give me unlimited in-flight internet for $20. Maybe antartica has worse reception, but cost isn’t the issue.
So? The comparison still makes no sense. Those switches cannot be accidentally flipped, and they are in a place where the pilots' hands have no action to take at all during that period. That is very different from mixing up two similar weapons in a similar location.
The pilots have no business with their hands in the area of those switches in that phase of the flight (9:30+ in the video). They don't even have to touch the throttle, and even if they did, that's a long way from where you touch the throttle down to the base where those switches are. Which you can't just flip either.
How is that even remotely similar to that cop's situation?
Suicide is quite a stretch without any supporting evidence from the pilots' backgrounds. I would take mental fog, cognitive overload, wrong muscle memory, even a defective fuel cutoff system over suicide.
Agreed. The sequence of events also supports this.
I believe one of the pilots made a terrible muscle memory mistake and cutoff the fuel instead of raising the landing gear. This would explain why the landing gear was never raised, why the pilot who was accused of cutting off the fuel denied it (in his mind he had only retracted the landing gear) and why the engines were turned back on after presumably realizing the mistake.
Not that humans are known to behave rationally when trying to commit suicide, but it’s interesting that the switches were re-engaged successfully without protest or a fight. It’s just an interesting detail to wonder about.
The reasoning I’ve heard is: it didn’t matter anymore, the damage was already done and there was no way any attempts at recovering from it would have been successful.
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
Or more precisely, the signals which come from them were found to behave as such.
Without any audible record of turning the switches off, I wouldn't blame the pilots without first checking the wiring and switches themselves for faults. This reminds me of the glitches caused by tin whiskers.
But from the audio recording it seems like one pilot is noticing them bering in the CUTOFF position, and asking why (and moving it back). If the switch was actually in RUN, but some other issue caused the signal to be sendt, the pilot would see it beeing in the RUN position, not CUTTOF.
You can't yet - what we have is this sentence from the report: "In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff.
The other pilot responded that he did not do so."
It's not a direct quote or transcript, it's reported speech.
This is very clearly EAFR data, so the logical/electrical switch state. Nothing about the mechanical state of the switches has been mentioned, except a picture that shows their final state to be in the RUN position (which makes sense given the relight procedure was ongoing).
From what I understand, the relight procedure involves cycling these back to CUTOFF and then to RUN anyway. So it is not clear if they were mechanically moved from RUN to CUTOFF preceding the loss of thrust, or cycled during relight.
I agree, there's a significant distinction between "the switches were (physically) flipped" and "the circuit was opened/closed".
In this case, it may be a moot distinction, particularly if no physical evidence of fault or tampering has been discovered in investigation. But, in theory, very important - there's a lot of potential grey-area between the two statements.
The proximity of the incident to the ground may also increase the possible attack vectors for simple remote triggers.
My understanding from what we've been reading is that these are physical switches that cannot be moved using remote triggers. Wildly speculating, there _may_ be a possibility that the _effect_ of the switch may be triggered remotely, if it's a signal being read by a control unit or computer of some sort that then actuates the specific electromechanical components. But it would seem impossible to move a physical switch to do it.
As an analogy, if you have a smart lock, you can remotely trigger the _effect_ of turning the key using (let's say a bluetooth control), but if a key is inserted into the keyhole, unless there is two-way mechanical linkage, that key _will not turn_.
If that was the case, it does seem a bit odd that there was a one second gap. But yeah, still worth investigating, if that’s even possible given the extensive damage.
> It's difficult to conclude anything other than murder-suicide.
The balance of probability might tend to support that hypothesis. However I'm wondering if it was just something involuntary. My ex for instance who learned to drive on a stick shift would randomly stall the engine after a few weeks driving an automatic.
> And both pilots deny doing it.
> It's difficult to conclude anything other than murder-suicide.
You’re trying to prove a negative here.
I am not familiar with the 787 operations, but there are a few issues that need to be sorted out first:
- altitude when pilots start the after takeoff checklist
- if there are any other switches that are operated in tandem in the general vicinity of where the engine cutoff switches are
- if the cutoff switches had the locking mechanisms present, and if not, if they could be moved inadvertently by the pilot flying hand
Discarding other possibilities in an investigation can have adverse consequences.
Did you ever always push the right buttons every time?
The switches have lockout mechanisms that prevent accidental triggering. I'm not a pilot, but these guys are, and they find it exceedingly unlikely that anyone would switch both off by accident:
You have to time it spy movie right to ensure dying.
This is what I am debating.
There are too many variables you need to account for.
For example, I want an expert opinion about the tone in the cockpit when the other pilot said “No, I did not touch it” or what was said. Is it calm? Surprised? Cold?
> Did you ever always push the right buttons every time?
A whole world full of 787’s is pushing the right buttons every single day. If we’re talking about accidentally pressing buttons it seems we’d have seen incidents before.
I wonder if the switches are still in tact after the crash? Can they verify that the switches are mechanically sound? If so, seems highly likely it was intentional.
I'd suspect the wiring leading from the switches to the engine controllers first, especially since it looked like both circuits cut out nearly at the same time.
This is speculation again since I don't really know, but my understanding of aviation engineering is that there would be two separate controllers for each engine connected to these two switches. At no point would they be connected to the _same_ control unit. The really short time (~1s) between the two being cutoff is the difficult thing to explain here.
You have to pull the switches out (against a spring) to be able to move them over a notch and flip them. Not really something you can just mistake for another switch or bump into by accident.
I'd liken it to turning off the ignition by turning the key while driving your car. Possibly something that could happen if you're really fatigued, but requires quite a mental lapse.
Is it possible to rest the switch on the notch? Does the switch make contact if the switch is in the RUN position but the switch is not completely down?
That is, is it possible they flipped the switches over to RUN but did not seat the switches properly, and instead leaving them on top of the notch, with later vibration causing the switches to disengage?
Just trying to think of some semi-plausible non-active causes.
?? One pilot to other: why cut-off. Other: Did not do it
08:08:52 Engine 1 run
08:08:52 Engine 2 run
1 second to switch them both off and then 4 seconds to switch them both on. No one admitted to switch them off. They are probably going with fine comb over the audio and also the remains of the chared switches.
Looks like the engines react very quickly to cut-off so it is not clear whether the question about the cut-off is prompted by a glance to the switches or the feel of the airplane.
The big question is whether the switches were moved or something made it seem as if the switches were moved.
Well in the murder-suicide scenario it makes sense for the culprit to turn them off as quickly as possible. The longer time to turn them on could plausibly be a struggle or simply needing to fly the plane while reaching for each switch individually.
> Looks like the engines react very quickly to cut-off so it is not clear whether the question about the cut-off is prompted by a glance to the switches or the feel of the airplane.
The workload is pretty high during the takeoff phase. The engines react right away when fuel flow is stopped. The engine displays can have some lag before data is updated.
Relighting an engine at low speed is not feasible - most need 230-250kts IAS before attempting the operation.
Maybe you could do it if the APU was still running and could provide compressed air, but it takes about 20-30 seconds to start up amd then probably 5-10 more to spool up to full thrust. I am speculating here a bit, but the pilot did not have enough time to save the plane even if he did everyting right and as fast as humanly possible.
All this aside is overshadowed by the limited amount of time the pilot flying (I would assume the captain in this case since there was only one ATPL pilot in the cockpit) had to troubleshoot the issue of a dual engine failure - as this is what would have felt to him - during takeoff.
My bad. I assumed it was the captain since the report says the FO only has a CPL license. And I was a bit surprised he could fly on a comercial airplane with only that kind of license and not an ATPL one.
Did you mean to say you can activate the switches with one hand simultaneously? That is probably what the above commenter assumed you meant. Since lifting and twisting two switches simultaneously with one hand seems challenging.
snypher: You can do them with one hand. [Ed. This is ambiguous and could be read as "one hand, simultaneously". In fact, doing it with one hand non-simultaneously would be a weird claim to make of a simple knob. See also ajb's comment below.]
zihotki: Really? They are not close together and have a spring mechanism. [Ed. Seems to believe snypher is claiming simultaneous operation.]
Context is both these switches being turned off with a 1 second gap. Doing it with one hand simultaneously would possibly explain it, otherwise it doesn’t seem relevant.
I wonder if they could theoretically rest on top of the notch, not fully locked into either position and flip accidentally. No idea how the switches behave when not all the way up or down, but the notch looks pretty long and flat so it could be possible.
It could be defective switch springs, fatigue-induced muscle memory error, or something else. The pilot who did it saying he did not may not have realized what he did. It's pretty common under high workload when you flip the wrong switch or move a control the wrong way to think that you did what you intended to do, not what you actually did.
That said Boeing could take a page out of the Garmin GI275. When power is removed it pops up a "60s to shutdown dialog" that you can cancel. Even if you accidentally press SHUTDOWN it only switches to a 10s countdown with a "CANCEL" button.
They could insert a delay if weight on wheels is off. First engine can shutdown when commanded but second engine goes on 60s delay with EICAS warning countdown. Or just always insert a delay unless the fire handle is pulled.
Still... that has its own set of risks and failure modes to consider.
If its both engines you're fucked anyway if its shortly after takeoff.
But I'm an advocate of KISS. At a certain point you have to trust the pilot is not going to something extremely stupid/suicidal. Making overly complex systems to try to protect pilots from themselves leads to even worse issues, such as the faulty software in the Boeing 737-MAX.
Was thinking this same thing. A minute feels like a long time to us (using a Garmin as the example said) but a decent number of airplane accidents only take a couple minutes end to end between everything being fine and the crash. Building an insulation layer between the machine and the experts who are supposed to be flying it only makes it less safe by reducing control.
Proposed algorithm: If the flight computer thinks the engine looks "normal", then blare an alarm for x seconds before cutting the fuel.
I wonder if there have been cases where a pilot had to cut fuel before the computer could detect anything abnormal? I do realize that defining "abnormal" is the hardest part of this algorithm.
The incident with Sully landing in the Hudson is an interesting one related to this. They had a dual birdstrike and both engines were totally obliterated and had no thrust at all, but it came up later in the hearing that the computer data showed that one engine still had thrust due to a faulty sensor, so that type of sensor input can't really be trusted in a true emergency/edge case, especially if a sensor malfunctions while an engine is on fire or something.
As a software engineer myself I think it's interesting that we feel software is the true solution when we wouldn't accept that solution ourselves. For example typically in a company you do code reviews and have a release gating process but also there's some exception process for quickly committing code or making adjustments when theres an outage or something. Could you imagine if the system said "hey we aren't detecting an outage, you sure about that? why don't you go take a walk and get a coffee, if you still think there's an outage in 15 minutes from now we will let you make that critical change".
If the computer could tell perfectly whether the engine “looks normal” or not, there wouldn’t be any need for a switch. If it can’t, the switch most likely needs to work without delay in at least some situations.
In safety-critical engineering, you generally either automate things fully (i.e. to exceed human capabilities in all situations, not just most), or you keep them manual. Half-measures of automation kill people.
But humans can't tell perfectly either and would be responding to much of the same data that automation would be.
I wonder if they could have buttons that are about the situation rather than the technical action. Have a fire response button. Or a shut down on the ground button.
But it does seem like half measure automation could be a contributing factor in a lot of crashes. Reverting to a pilot in a stressful situation is a risk, as is placing too much faith in individual sensors. And in a sense this problem applies to planes internally or to the whole air traffic system. It is a mess of expiring data being consumed and produced by a mix of humans and machines. Maybe the missing part is good statistical modelling of that. If systems can make better predictions they can be more cautious in response.
If the warning period is short enough is it possible it's always beneficial or is 2-3 seconds of additional fuel during a undetected fire more dangerous?
I'm doing it all the time while rebasing commits or force pushing to my branch. Sometimes I would just click the wrong buttons and end up having to stay late to clean the mess. It's a great thing I'm not a pilot. I would be dead by now.
Delay is probably worse - now you're further disassociating the effect of the action from the action itself, breaking the usual rule: if you change something, and don't like the effect, change it back.
This is a place that puts "Hacker" in the name despite the stigma in the mainstream. Given the intended meaning of the term, I would naturally expect this to be a place where people can speculate and reason from first principles, on the information available to them, in search of some kind of insight, without being shamed for it.
You don't have to like that culture and you also don't have to participate in it. Making a throwaway account to complain about it is not eusocial behaviour, however. If you know something to be wrong with someone else's reasoning, the expected response is to highlight the flaw.
For me it's mainly about intent/unearned confidence.
If someone is speculating about how such a problem might be solved while not trying to conceal their lack of direct experience, I'm fine with it, but not everyone is.
If someone is accusing the designers of being idiots, with the fix "obvious" because reasons, well, yeah, that's unhelpful.
I don't think most think they know better but it's frankly fun to speculate and this is a casual space rather than the serious bodies tasked with actually chewing over this problem in earnest.
It literally is. Accidental/malicious activation can be catastrophic, therefore it must be guarded against. First principles.
The shutoff timer screen given as an example is a valid way of accomplishing it. Not directly applicable to aircraft, but that's not the point.
> "ugh can't you just do what garmin did"
That's your dishonest interpretation of a post that offers reasonable, relevant suggestions. Don't tell me I need to start quoting that post to prove so. It's right there.
(Different user here) Hacker News' "culture" is one of VC tech bros trying to identify monopolies to exploit, presumably so they can be buried with all their money when they die. There's less critical thinking here than you'd find in comments sections for major newspapers.
If Boeing only had the foresight to hire an army of HN webshitters to design the cockpit, this disaster could have been averted.
All the controls would be on a giant touchscreen, with the fuel switches behind a hamburger button (that responded poorly and erratically to touch gestures). Even a suicidal pilot wouldn't be able to activate it.
Yeah, people shouldn't bat ideas around and read replies from other people about why those ideas wouldn't work. Somebody might learn something, and that would be bad.
Reminds me of 2017 Las Vegas shooting. The perpetrator looked and acted completely normal till the day of shooting and all his issues like anxiety or losing money was nothing far from ordinary. And what seems all of a sudden did a well planned shooting and didn't bother to leave a note or tell his story.
There's 0 reason to conclude murder-suicide, there's an infinitude of things that could have the same result, and both pilots denied it to eachother: how is that presented as proof?
I hope I don't need to explain why the fact no one knew in advance the Las Vegas shooter was going to shoot has ~0 similarities with the situation as we know it, and banal similarities with every murder.
Could you explain more? There's too many negatives in that last sentence for my decaffeinated early morning brain. I'm titillated by the idea there's a way to justify making up things so I really want to parse it.
>It's difficult to conclude anything other than murder-suicide.
This kind of attitude gets innocent people behind bars for life. Disgusting.
It's difficult to conclude anything until the investigation is finished and I hope the ones who are carrying it out are as levelheaded, neutral and professional as possible.
A rodent chewing on wires. Vibration-induced chafing. Tin whiskers causing an intermittent short. There are many possibilities, those came to mind first.
But why does the pilot then comment that they are in the CUTTOF position and move it to RUN? A mechanical failure would have to also move the physical switch in the cockpit for the audio recording to make sence.
You have the exact CVR audio? The report says "one of the pilots is heard asking the other why did he cutoff" which I interpreted to mean one of them noticed the engines shutting down, and asked the other if he did that.
Then he would have asked the other pilot why the engines are shutting down. It seems a lot more probable that he glanced at the switches before asking such an explicit question.
It amazes me that some people can ever make it out the door if they spend all their lives contemplating a series of increasingly unlikely possibilities.
We know that the switches physically moved from the run to the cutoff position because one of the pilots noted that they were in the wrong position. We know that they were moved back to the run position because they found in that position. I don't understand how a short could explain that - it really seems like someone would have had to physically move the switches.
What we have is reported speech: "In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff. The other pilot responded that he did not do so."
So we don't know the exact words used. Did he say for example, "Why did you move the switches to cutoff" or did he ask "Why did you cut off the engines"? If there are indeed two shorts (astronomically low as those probabilities are), the other pilot would say "I didn't", look around confused and then (possibly?) flip both of them down and back up? Which could explain the 4s delay in pulling them back up.
Speculation, but since we do not have actual transcripts or recordings, all I'm doing is answering speculation with more speculation.
Do we know that the pilot noticed they were in the wrong physical position, or did some other status indicate the engie fuel had been cut?
I would be surprised if there was only one channel for this information
In the last mentour pilot livestream, they showed the simulator and both engines, and there's a little graphic near the cutoffs showing engine state and performance. Also, in _this_ livestream as soon as the report was released, Ben mentions in response to a question that if you cut off the engine, a lot of electrical systems are going to face power cuts, so there will be alarms blaring all over the cockpit. So, yes. There are many channels of information here.
It's not that rare, and there are institutional factors (such as seeking treatment for psychosis being career-ending for a pilot) that incentivize serious pilot mental health crises being untreated.
This is highly reminiscent to me of this case. [0] The co-pilot accidentally hit the wrong switch and then quietly corrected his mistake later, without resetting the previous switch (which led to feathering).
Cutting the engines within seconds of leaving the ground doesn't fit suicide very well. I'd expect something more like flying into the side of a mountain or heading really far out into the Indian ocean until you vanish from radar and cause a big mystery.
For instance, you might deliberately kill yourself by driving your car really fast into something solid, but you probably wouldn't try to do that while backing out of the garage.
I think it is opposite.
Flying into a mountain & etc would require one pilot to somehow incapacitate another pilot.
Cutting fuel off, if done on takeoff, is not recoverable (engines can’t relight and spin up quickly enough).
I know this thread runs the gamut of armchair experts, pretend experts, and actual experts and there's no telling who is which but I really want to know why the downvotes and why this is not a good idea.
The idea is to notify for crucial settings, replace vocal confirmation (probably) already in the SOP anyway, reducing mistakes in bad faith or otherwise.
Don't some planes already have an automated announcement for seatbelts on?
Only reason I can think of why it's not there yet is the cost (whether $$$ or design opportunity) of cramming that in the already-cramped cockpit.
My first instinct is that the suggestion is overfitted due to hinsight bias. This particular accident happened to involve these particular switches so let's add a warning to these switches. Duh!
Some problems that immediately come to mind:
- For which settings is there going to be a voice confirmation? Is their confirmation more important than all the other audio warnings?
- During emergency situations, when pilot workload is high, will these only add to that workload, making the emergency even worse?
- Will the pilots get so used to hearing these every day that their brains will simply tune them out as background noise?
Really though, if a pilot wishes to doom an aircraft, there's 1000 different ways they could do so. The solution to this problem likely lies in the pilot mental health management department, rather than the fuel cut off switch audio warning one.
Pretty obviously a bad joke and a bad idea IMO. I did not personally downvote, but I think it deserves its current score.
Look at the timeline of the events. The switches were shut off, noticed to be shut off, and restored to the proper position within 10 seconds with the current system. Insufficient notification that the switches have been turned off was clearly not a problem in need of a solution. It would be slower and more challenging to understand an automated verbal announcement than the surely extremely obvious sudden lack of thrust and all engine dials rapidly dropping to zero.
So it wouldn't contribute at all to solving this particular case, would only be a slightly annoying distraction in the more normal case of normal aircraft shut-down after completing its flights, and would be a potentially hazardous distraction in the intended emergency case of engine is on fire and fuel must be cut off immediately, where there's probably a bunch of other extremely important and urgent things to pay attention to and do other than a silly automated warning telling you what you just did.
Do you know if the mechanical position of the switch guarantees its electronic state without any possibility for hardware malfunction? If no, then you are claiming a person made one of the most grave acts of inhumanity ever.
This sounds to me like an electronics issue - an intermittent, inadvertent state transition likely due to some PCB component malfunction
The time between the two switches being activated and then them being switched back on after being noticed strongly suggests that they were actually manipulated. Malice looke very likely to me. An investigation into the pilots life may turn something up, I guess.
It’s worth noting that Premeditation or “intention” doesn’t have to factor into this.
Studies of survivors of impulse suicides (jumping off of bridges etc) indicate that many of them report having no previous suicidal ideation, no intention or plan to commit suicide, and in many cases no reported depression or difficulties that might encourage suicide.
Dark impulses exist and they don’t always get caught in time by the supervisory conscious process. Most people have experienced this in its more innocuous forms, the call of the void and whatnot, but many have also been witness to thoughtless destructive acts that defy reason and leave the perpetrator confused and in denial.
> The time between the two switches being activated and then them being switched back on after being noticed strongly suggests that they were actually manipulated
How so? It is just as likely to be an intermitted electronic malfunction.
And then 10s later the switches magically fixed themselves? The likely not electronically connected switches since that would compromise engine redundancy?
It is, and one would expect that a single switch failure would be far more probable, so how often have we had switch failure single engine cutoff in the 787?
It's interesting to see how people manage incomplete information.
You could have made the same assumptions after the first MCAS crash, much like boeing assumed pilot error. It's easy, comforting and sometimes kills people because it makes you stop looking.
>Service Bulletins by Boeing issued in year 2018 recommending to upgrade the fuel switches to locked versions to prevent inadvertent flip of the switches, as well as the FAA/GE issued Service Bulletin FAA-2021-0273-0013 Attachment 2 relating to loss of control issue (also see above) were NOT implemented by Air India.
You've linked to something regarding an ECU component. Nothing about fuel switches. "This Service Bulletin provides instructions to replace the EEC MN4 bridge ball
grid array (BGA) microprocessor"
Because that maintenance check is an optional one as stipulated by Boeing. I don't think most users of the 787 themselves carry out the check, so singling out Air India for this alone is just bad faith
No they don't, do they. That also corroborates the fact that they could be both switched to CUTOFF within a second, like the report states. That impossibility was raised by parallel threads here. In the video they are both switched on even faster than 1 sec apart, or, at least it feels like it.
What makes me more inclined to suicide is that this might have been the perfect time to do this so that even a small interruption in fuel would be catastrophic.
If this is the case, you have to then think about why this pilot would want suicide but also murder all aboard the plane. It's a bit irrational if they wanted to just suicide - you can easily just cut your own throat, hang yourself, or jump off a tall building.
Fire, probably. But also, how complicated would you make the system if you needed to prevent certain switches from working during certain times of flight? At some point... we're all just in the hands of the people in the cockpit.
Sure, but you can open the door, pull the handbrake, or turn the wheel so hard you lose control of the vehicle. These are all similarly preventable, but maybe not worth the risk of being unable to open the door, brake or steer if the safety mechanism fails closed, or if your situation is outside the foresight of its designer.
Also, you don't need multiple certifications and 1500 hours of experience to drive a car.
On my Tesla Model Y there's a hand brake on the push button of the right lever. On the left hand lever there's another push button, the windshield wiper liquid. Guess what have I mistakenly, and scarely, done twice already when driving at highway speeds when my windshield was a little dusty?
New designs are prone to ill decision-making from engineers, drivers and pilots alike. Every pathway of let's do it differently is the beginning of a journey of fine-tuning loops until stability.
A friend did exactly that in a manual transmission, doing 100km/h.
She was mad and said she has to jam it hard ( going for 5th and missed), but it went into reverse. And the gearbox literally hit the road when she let out the clutch.
There may be a good reason to cut fuel to one engine shortly after takeoff.
You could have a system that prevents both switches being thrown, and only in the specific window after takeoff, but you’ve also now added two additional things that can fail.
They look nice, but they can be turned on the C17 (and probably other military airplanes).
Commercial airplanes have safeguards against in-flight thrust reverser deployment. That is why they only work in tandem with the ground sensing systems - like the airplane must firmly believe both main landing gears to be physically on the ground for both reversers to be operational.
Disable the fuel system cutoff controls during the takeoff climb phase of flight. Once the aircraft loses contact with the runway, these controls shouldn't function without tripping certain thresholds (speed & altitude), or following a two-man procedure that is physically impossible to execute solo. In any other flight regime, the controls function as originally designed.
The danger of a burning engine is irrelevant if you are heading into terrain.
Now you created a fuel system cutoff control inhibition system which may malfunction in its own ways, e.g., refuse to cut off fuels from a burning engine because it thinks the plane is too low due to faulty altimeter reading.
> The danger of a burning engine is irrelevant if you are heading into terrain.
Not quite. When you hit the ground you do not want any fuel leaks or hot surfaces as much as possible. That is why for example engines are shutdown when doing an emergency belly landing, to try abd prevent the airplane from bursting into flames.
As long as you also eliminate the possibility of maintenance problems and defects in automation, and have perfect microscale weather forecasts, and still have overrides for the human safety pilot that can still... wait a minute.
It's safe to state these fuel cutoff switches aren't to be touched in-flight unless the word 'fire' is said beforehand. Even then, you only perform fuel cutoff for the flaming engine. If the copilot was busy with takeoff, there is exactly one other person in the entire world that could have flipped both switches. We may never know which one flipped them back.
Yep. Fan blade off, shroud separation, HP disc separation, compressor stall, FOD ingestion/bird strike, EGT rise, oil system issues. Very unlikely events but still possible events that need a prepared response to and capabilities to manage the aircraft. The presumption is that the crew is trained, diligent, disciplined, and concerned with survival. Without that, aircraft would need to be unmanned and flown by AI lacking in ability to handle any unforeseen events creatively.
I don't want AI planes either, but the alternative of unmanned is ground-based drone operators who lack the survival interests of being on the planes. As such, I want non-AI flown planes with sane, stable, rested, practiced, experienced, sober pilots on the plane that isn't overly complicated and is reliable.
As we just reported, the report says that according to data from the flight recorder both the fuel control switches, which are normally used to switch the engines on or off when on the ground, were moved from the run to the cutoff position shortly after takeoff. This caused both engines to lose thrust.
The preliminary report suggests this is pilot error.
From my (limited) understanding you cannot really switch these off inadvertently as they require a couple of actions in order to be switched off. So it would mean one of the pilots switched these off (and they were a few seconds later switched on again but it was too late).
But there was audio, too, and one pilot asked the other "why did you switch these off" and the second one said "I didn't".
The India AAIB website (https://aaib.gov.in/) is not responding ... For anyone who read the report, was there information about the age & experience of the pilots?
reached v1, then when airborn fuel cut off. Seems like there was a FAA report like in 2018 that recommended few airplane models (incl this one) to check the fuel valves correctly, seems like air india didn't do it. Turns out it was made by Honeywell
Video would definitively show whether either pilot moved these switches or if some other mechanism caused the movement.
The aviation industry has consistently resisted cockpit video recording despite decades of available technology. The pilot unions argue privacy concerns, but cases like this demonstrate the value it would have. Current audio captured the pilots' denials, but without visual confirmation we may never be able to definitively determine who turned the engines off.
It’s interesting to see how many people are bending over backwards here to avoid coming to the obvious conclusion. If this was pilot suicide, it’s a terrible thing. If it was somehow an error (which seems very unlikely) or two defective controls (which seems even more unlikely), then it remains a tragedy. But I don’t need to do mental gymnastics to come up with implausible hypotheticals.
This comment stream on HN is not a jury. We don’t have to refrain from making judgments right now about what happened. There is nothing wrong with rational people reaching a preliminary conclusion based on available evidence.
Rational people should also remain open to revising their judgments/conclusions if new information becomes available.
And we shouldn’t demand any specific consequences for anyone absent a trial.
It’s nowhere near an obvious conclusion. A failure with the locking mechanism or muscle memory confusion are just as likely, and probably other theories I’m not thinking of. More investigation is clearly needed, which is why this is called a preliminary report.
Dual failure of the locking mechanism is extremely unlikely.
These are not switches that are regularly used so a muscle memory issue also seems very unlikely (but is still the most likely non-suicide scenario)
The switch had to be operated deliberately, but still a UX fail on a modern aircraft if cutting off fuel to the engines does not result in an audible alert/alarm which both pilots can hear - especially at that altitude.
The switches were re-engaged within 10 seconds so isn't it possible they quickly heard a warning alarm, realised the issue and fixed it? (Of course, not quick enough in this case)
It would not make any difference. They were too low and did not have enough time to recover. They immediately switched back to on. Two captains is discussing it here (https://www.youtube.com/watch?v=SE0BetkXsLg).
And this can't possibly be all the audio if the other pilot noticed the switch position, I would expect a lot more cussing and struggle.
So they didn't notice the switch position? The switch was in the right position but not really? Is this a rarely used switch that one might not look at (or know where to look) during regular use?
Dual engine failure on takeoff gives them about as much time to react as if the front passenger grabbed the steering wheel while on a windy mountain road and yanked them off a cliff.
It only takes a few seconds to completely screw everyone, but a bit longer for the consequences to occur.
The report says the black box reports the fuel cutoff switches being activated. That doesn't necessarily mean that either of the two pilots activated them, it just means that the fly-by-wire system reacted to a fuel cutoff event.
"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. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cutoff.
In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff.
> That doesn't necessarily mean that either of the two pilots activated them
It does:
1. Those switches have physical interlocks and cannot be manipulated by any computer system.
2. The flight data recorder is measuring the position of the switches; they aren't inferring the position from some system state. There's a "position of this switch" channel.
The switches were physically moved in the cockpit, that's basically ground truth. The question now is who and why.
What is the path of the wires from the switch onward? Do they go into a digital input of the flight computer, or do they directly feed the fuel control valves?
The 787 entered service with an improved fly-by-wire flight control system. Rather than mechanical processes, the systems convert flight deck crew inputs into electrical signals. Still, there were additional advancements with the type."
Can't find a definitive source right now, but everything is implying there are discrete lines - at least one for command signal to the FADECs, and a separate sense line to the DFDAU for packaging up and sending to the EAFR. That lines up with design philosophy on this stuff of sensing control input data as close to the source as you can get.
Thanks for looking. I worked for Boeing (satellites, not airplanes) for a good part of my career, and I was there when Dennis Muilenburg pushed through his cost saving measures. It was the same culture that created the problems with the 737-MAX. Experienced design engineers were replaced/outsourced and the culture of safety was sacrificed. One example here:
787 (Dreamliner) was pushing hard for weight reduction, and it would not surprise me at all if the switch output fed a digital computer input rather than routing directly to the fuel shutoff valves, but I don't have any direct knowledge of this.
Then why do we see the pilots notice the cutoff, move the switches back, and the engines respond as expected? The switched cannot move themselves. We’d expect to hear more commentary and confusion if the cutoff was active and the switches still in Run.
There would have likely been an indication on the glass cockpit displays that the fuel had been cut off, perhaps the pilot flying noticed this and asked the captain.
Yes, there is, but the reaction to that would be to look at the position the cutoff switches were in. We didn’t hear “wtf, they’re in Run” - the report says they just moved them from Cutoff to Run and the engines responded as expected.
I think you have to really reach to make this not pilot error. I know it’s appealing to call this a Boeing problem, but the evidence just from this prelim report is very compelling.
Until we hear the actual CVR audio, I don't think we can assume much. They are under a very high stress at that point in the flight, and while the "WTF?" might be going through their minds, all they could've resorted to is toggling the switches off and on again.
No, lacking other evidence (e.g. CVR recording) it doesn't mean they have been moved. The wiring in between the switches and the engine+FDR could've also developed an intermittent fault.
The fact that your car's engine stops doesn't mean you turned the ignition switch off. Anyone who has had to troubleshoot a car with intermitent electrical faults knows that.
> This was not suicide, or murder-suicide; it was one of the most horrific mass murders in history, in which the guy that did it happened to lose his life in the process.
Even taking intent for granted, to deny suicide in a case like this would be to suppose that the person responsible expected to survive while everyone else died. What could possibly support that conclusion?
He appears to have meant something like “this isn’t just common murder-suicide: it is a particularly heinous version of murder-suicide that I wish there were a stronger word for” but phrased it confusingly.
> This was not suicide, or murder-suicide; it was one of the most horrific mass murders in history, in which the guy that did it happened to lose his life in the process.
Why wouldn’t this qualify as a murder-suicide, assuming your theory is correct?
I guess I let my emotions get in the way. But nobody seems to be saying that we’ve witnessed one of the worst acts of mass murder in history. Most of the notorious serial killers don’t come close to killing 300 people.
It feels qualitatively different than someone pointing a gun at someone else and then themselves, which is usually what pops to mind when you hear “murder-suicide”.
As someone with no qualifications on this beyond occasionally playing some flight simulators, I can't think of a reason you would ever intentionally move the switches in flight (barring an emergency like a leak or fire or something) and unintentionally doing so seems extremely unlikely since generally "switches meant to be operated on the ground" are located well out of the way of "switches meant to be operated in flight". Though I believe Boeing does have them by the thrust levers, every type of fuel control switch I've seen has some sort of guard or mechanism that makes it effectively impossible to move the switch by simply bumping it.
So I can't imagine how it could have been done accidentally.
I am, and I’m willing to stake my reputation on it. If I’m wrong, I’ll hang up my hat and never cover live news again.
Pilots are drilled from day one that the fuel switches are sacred. After a few accidents where one engine failed and the pilot accidentally turned off the remaining functional engine, the training was overhauled so that it would be impossible for it to be an easy action done by mistake. One pilot is required to ask the other for confirmation before toggling the switch, I believe. It wouldn’t be something you’d do from muscle memory.
> If I’m wrong, I’ll hang up my hat and never cover live news again.
It easy to say that when you know there's likely no way to prove or disprove whether it as an accident or not. Unless a pilot left a note stating his future intentions, there's no way to determine their state of mind.
Someone took their hand, pulled one spring-loaded switch into the off position, and then did it the other switch moments later. Is there any way that could be accidental?
If there was no mechanical failure, the only remaining possibility is deliberate action. And if it was mechanical failure, we’d see an emergency air worthiness directive being issued, which we haven’t.
People do things bizarre, inexplicable things all the time. It's called a brain fart... the human brain is complicated, sometimes wires just get crossed.
Honestly I think the chances are good that you're right, but the way you're presenting it as absolutely certain strikes me as overconfident, borderline arrogant.
Also, what's with the whole "staking your reputation" thing? What reputation? Are you some kind of famous journalist? Is there some reason we should care about you "covering live news" ? Serious questions -- I personally have no idea who you are.
I also don't recognize this guy's name, but I do find it ironic that his profile is possibly the most well-linked to a other identities I've ever seen on HN: https://news.ycombinator.com/user?id=sillysaurusx
It’s mostly a very public "If I’m wrong, I won’t ever do this again." I’ve been writing informative HN comments since 2008 on various accounts. It’s a big deal to me not to spread misinformation or be mistaken in a situation like this.
The victims also deserve to be acknowledged. At this point the overwhelming body of evidence points to a deliberate act. Pilots are trained never to touch the fuel switches in flight, and (I believe) there is a verbal confirmation required before toggling. This captain had over 8,000 hours.
The reason I’m so confident is because I trust the system. It’s designed so that if either of the two pilots do anything, they verbally call it out, e.g. "gear up." A callout like that followed by fuel switch cutoff would indicate it was accidental. But as far as I know, there was no callout.
The pilot flying is also the one who asks for gear up and such. It’s the job do the pilot monitoring to perform those actions.
Suppose it was accidental. That would mean the pilot flying was fiddling with switches instead of flying; that’s against SOP. Or it would mean the pilot monitoring was performing uncommanded actions, which is also against SOP. It’s not something that happens on a whim. Both are contradictions, hence, no accident.
As for being overconfident or arrogant, what matters to me is accuracy, and passing along that accuracy. No one seemed to be willing to publicly call this a malicious action, so I did. If I’m wrong, you can be sure I’ll feel terrible for weeks, post an apology in the thread that shows I was wrong, and then bow out in disgrace, never to cover news again.
People here did the same thing when the common belief was that there was a non-zero chance of nuclear war. I was one of the few voices in that thread saying absolutely not, stop stressing yourself out for no reason.
I’m simply one voice of many. As always, it’s up to the reader to decide what to believe.
> It’s a big deal to me not to spread misinformation or be mistaken in a situation like this.
Then why not either wait until there's more information or temper your remarks by acknowledging there's still ambiguity? That would directly hedge against spreading misinformation, whereas staking your reputation on it and then shutting up if you're wrong only works after the misinformation has spread and doesn't seem very productive.
I think the right response to realizing you've spread misinformation (in the event that you turn out to be mistaken [I think it's 60-40 in favor of deliberate]) is to temper your statements and rededicate yourself to checking the facts, not removing yourself from the discussion altogether. And if you were keeping your mouth shut, wouldn't you continue to see discussions you could meaningfully contribute to, and after a while wouldn't you wonder whether anyone was really benefitting from your silence?
I was about to leave a big reply, but then I remembered that the guidelines ask that we only comment when feeling intellectual curiosity. That’s not what I’m feeling now, so I’ll go spend the evening with my daughter. I hope you have a nice evening as well.
> It’s mostly a very public "If I’m wrong, I won’t ever do this again." I’ve been writing informative HN comments since 2008 on various accounts. It’s a big deal to me not to spread misinformation or be mistaken in a situation like this.
I understand that you appear earnest. However, your history of multi-accounting on this site makes your promise to never post on a given topic again meaningless to me, because I have no expectation that you wouldn’t continue to post about it on other accounts that we don’t know about at this time, possibly because they haven’t even been created yet.
The report indicates the cut off switches were found, and were in the RUN position. However, the report does not indicate if the locking mechanism was functional; given the thermal damage, it might not be possible to determine.
I'm also interested in the earlier switch defects where the switches were installed with the locking mechanism disengaged on some 737s and inspection was advised for 787, but the incident aircraft was not inspected.
The airworthiness directive for that [1] indicates switches with locking disengaged should be replaced, but I wonder if it's possible to reingage the locking somehow, which could result in a situation where the locking wasn't engaged, the switches changed inadverdently and then when restored the run position the lock was engaged... that's a big reach, of course.
All that said, assuming the switch was working as designed, there's a semantic argument around deliberate and intentional. If the switch requires specific action, it's fair to call it deliberate action; but if the switcher thought they were activating a different switch, it's not murder.
Either way, there's no sense rushing to a conclusion of murder. Assuming one of the pilots activated the switch, they have already died and they are beyond the effects of human judgement; so we may as well wait for further information.
The switches require that you pull them out, move them to the end position and then push them back down, and it was two switches. It could have still took off on one engine. This is essentially the turn off plane switch. It would seem to almost impossible that it would be an accident.
Not possible it's an "I bumped it" type of accident, maybe.
It's quite possible it's a "performed the wrong muscle memory at the worst possible moment" type of accident. This is unlikely, but anyone who thinks such a mistake is impossible doesn't know anything about human factors.
Unlikely just means "low probability." There are thousands of flights per day, so it's only a matter of time.
You mention "brain fart". There is certainly a long history of pilots selecting the wrong lever, or wrong switch. So, it is possible the pilot who denied switching the fuel off thought he had switched something else.
My understanding is that after several incidents of pilots shutting off the wrong engine, the training was overhauled so that from day one they treat fuel switches as sacred. I heard that it’s required to ask for confirmation before toggling the switch, just to be absolutely certain. It’s not really something that can be done by muscle memory during flight, and especially not during takeoff.
If he was trying to do something else, he would have called it out. E.g. an audible “gear up.”
Also, it took 10 and 14 seconds to switch them back on. If it was an accidental switch, you would think it would have been quicker to switch them back.
I have a couple of those type of switches, though smaller, in my parts bin. They were from some piece of surplus equipment that got junked. Where I've seen them used is in a crowded control panel where they might just get bumped. The two red plastic levers to the left are another type of safety switch: The lever is spring loaded, and covers the handle of a toggle switch.
In my view it would be quite hard to move them by accident, and probably not possible to move at once.
It would be interesting to know if the plane has any other switches of the same type, that are routinely activated.
Sadly not. It’s a physical switch with no capability of a remote toggle. The flight data recorder clearly shows one was toggled off within a second of the other, which rules out almost every non-intentional scenario.
It's an entirely different shape, different location, and different motion from any other switch they could be looking for. Suicide is a way more likely explanation.
Is this a switch that has a dedicated connection to the corresponding cutoff valve? Or does it go through some common digital bus that passes commands? If so, how well is this bus protected?
Another commentator has pointed out that the flight data recorder records two signals - one for the switch itself, and one for the actual valve movement.
I take your point that we should always be suspicious of complicated, digital buses, and this is not the final report, so there’s still plenty of time to uncover weirdness. However, if the flight date reporter shows the switch being thrown, and then a few milliseconds later, shows the valve starting to close, and the same sequence happening shortly there after on the second switch and valve, I feel this would really limit the likelihood of any digital shenanigans.
Studying how humans make errors is a fascinating field. Simply banning someone who's made a "slip" error as hypothesized wouldn't actually reduce the likelihood of this error occurring in the future. These sorts of errors are stochastic and could happen to anyone at any time. Preventing them requires a lot of thought.
It did glide briefly, the glide path took it directly into a school building.
Right after takeoff at low altitude is basically the worst place for this to happen. Speed and altitude are low so gliding is going to be a short distance and happen quickly.
If there had been a perfect empty long flat grass field in that location it may have been salvageable, but also right after takeoff the plane usually has a heavy fuel load which makes for a much riskier landing.
Edit: This article has a map showing the glide path:
They only ever got a few hundred feet off the ground.
Yes of course the plane glided once the engines stopped, producing thrust, just like all planes do. But just like all planes, and all gliders, gliding means trading altitude for velocity - giving up precious height every second in order to maintain flight. At that stage in the flight, they just didn’t have enough to give. If the same thing had happened at 30,000 feet, it would be a non-event. They would glide down a few thousand feet as the engines spool back up and once they return to full power, everything will be back to normal. Or if for some reason, the engines were permanently cooked, you’d have maybe 20 to 30 minutes of glide time so you’ve got a lot of time to look around and find a flat spot. But you just don’t have enough time for all that to happen When you’re a few hundred feet off the ground.
I’ll take this as an honest question. The simple answer: too much mass, no clear landing path, not enough speed or altitude to turn to find one and glide to it. In short, not enough time. Once the engines cut, that thing probably dropped like a brick.
Impossible. Low and slow conditions with insufficient energy to 180 return or crash land safely straight ahead in any form. The power loss happened at the most critical phase of flight. Plus, they were on the heavy side.
Yes I acknowledge this. But I also retain control to the very last moment. I don't have to bank on the driver of my vehicle not being suicidal. If I feel another driver is dangerous, I can just stop. This obviously doesnt prevent all accidents but I've never been in a serious one.
That being said ive flown plenty of times. My fear comes from lacking any control and just finding out mid-flight were going down through no fault of my own. I wouldn't want to know, but then again air France 447 is terrifying too.
