[HN Gopher] Preliminary report into Air India crash released
___________________________________________________________________
Preliminary report into Air India crash released
Report:
https://aaib.gov.in/What%27s%20New%20Assets/Preliminary%20Re...
Author : cjr
Score : 357 points
Date : 2025-07-11 20:23 UTC (1 days ago)
(HTM) web link (www.bbc.co.uk)
(TXT) w3m dump (www.bbc.co.uk)
| rawgabbit wrote:
| Quote: 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.
| lazharichir wrote:
| 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".
|
| Was there are third one in the jump seat?
| rawgabbit wrote:
| The report only said the copilot was flying and the pilot was
| monitoring.
| fracus wrote:
| Sounds likely that one of them was sabotaging the flight.
| zihotki wrote:
| It does not suggest that. It only says they were turned off and
| no other conclusion given.
| mallets wrote:
| Well, shit. Suicidal?
|
| 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?
|
| 10 seconds between OFF and ON.
| chupchap wrote:
| From what I've read, it comes on the display as a warning
| lazide wrote:
| 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.
| rwmj wrote:
| 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?
| mtmail wrote:
| 56 years old, 15638 hours (8596 on this type) and 32 years old,
| 3403 hours (1128 on this type). Page 11 of the PDF report.
| foldr wrote:
| Report PDF here:
| https://aaib.gov.in/What's%20New%20Assets/Preliminary%20Repo...
| belter wrote:
| Not accessible. Have they heard about S3 ?
| foldr wrote:
| It loads for me, so I think the link will be useful for some
| people at least.
| burnt-resistor wrote:
| It's getting hugged by the world and they didn't use a CDN
| apparently.
| shoghicp wrote:
| mirror
| https://web.archive.org/web/20250711203907/https://aaib.gov....
| d_silin wrote:
| Report page that matters:
| https://x.com/exodusorbitals/status/1943782924576309732
| decimalenough wrote:
| > _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.
| chupchap wrote:
| Or a mechanical failure
| ceejayoz wrote:
| Both switches, at slightly different times? Seems pretty
| unlikely.
| userbinator wrote:
| A rodent chewing on wires. Vibration-induced chafing. Tin
| whiskers causing an intermittent short. There are many
| possibilities, those came to mind first.
| Epa095 wrote:
| 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.
| userbinator wrote:
| 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.
| bronson wrote:
| 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.
| userbinator wrote:
| Without listening to the CVR audio and knowing what they
| actually said, there's no evidence either way, and AFAIK
| they have not released that.
| apical_dendrite wrote:
| 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.
| fyrn_ wrote:
| 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
| shash wrote:
| 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.
| shash wrote:
| 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.
| mr_toad wrote:
| 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.
| Spooky23 wrote:
| Serious question: why is it so difficult to fathom that a
| deranged pilot could decide to commit suicide by plane?
| ExoticPearTree wrote:
| To answer your question: because it is a very rare
| occurence.
| cjbprime wrote:
| 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.
| BurningFrog wrote:
| All commercial plane crashes are very rare occurrences.
| shash wrote:
| Not difficult, but can you close an investigation on that
| note without going over other possibilities?
|
| What if there's another safety lesson to be learnt here?
| ceejayoz wrote:
| > 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.
| dehrmann wrote:
| > 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.
| sofixa wrote:
| 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.
| Aeolun wrote:
| > Damn. That's pretty quick to diagnose and take action.
|
| I have to imagine that "You are flying" and "You just cut off
| all fuel to the engines" must generate a pretty obvious
| claxon of warnings.
| alephnerd wrote:
| > It's difficult to conclude anything other than murder-
| suicide.
|
| Is it possible it could have been an accident or a mistake by
| one of the pilots? How intention-proofed are engine cutoffs?
| ummonk wrote:
| 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.
| joezydeco wrote:
| Report says the switches went to cutoff one second apart
| from each other. Can a human do the physical operation on
| two switches that quickly?
| snypher wrote:
| There's a good photo of them here;
| https://theaircurrent.com/aviation-
| safety/ai171-investigatio...
|
| You can do them both with one hand.
| zihotki wrote:
| Are you completely sure you can considering that they are
| spring loaded and they are like 7-10cm apart judging by
| the size of other controls?
| snypher wrote:
| I don't understand your question. I have done this
| myself, am I completely sure?
| cosmicgadget wrote:
| 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.
| mvdtnz wrote:
| It didn't happen simultaneously so this is irrelevant.
| cosmicgadget wrote:
| It is relevant to the interaction I replied to.
| ryandrake wrote:
| You're the only one who said "simultaneously."
| cosmicgadget wrote:
| See above.
| lanna wrote:
| Above commenter said _quickly_, not simultaneously
| cosmicgadget wrote:
| Jesus...
|
| joey: Can you switch them quickly?
|
| 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.]
|
| snypher: I am confused by the response.
|
| Me: [Tries to facilitate clarification]
| JumpCrisscross wrote:
| > _This is ambiguous and could be read as "one hand,
| simultaneously"_
|
| Not within the context of the thread.
| ra7 wrote:
| 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.
| JumpCrisscross wrote:
| > _Context is both these switches being turned off with a
| 1 second gap. Doing it with one hand simultaneously would
| possibly explain it_
|
| It would. So would switching both quickly in succession.
| One second is a long time--I can adjust power, prop, fuel
| pump and flaps in about that time.
| ra7 wrote:
| What I gathered from comments here is it's not a simple
| flick of the switch and it actually takes some effort to
| turn them off. Can you really do it twice within the span
| of 1 second?
| JumpCrisscross wrote:
| You pull it out and flip it. It's not easy to do
| inadvertently. But it's also not convoluted--you want to
| be able to quickly cutoff if there is an engine fire.
| ajb wrote:
| If you do them both with one hand, would they not be
| moved at the same instant rather than 1 second apart?
| lazide wrote:
| They require a per-switch motion, so unlikely.
| arp242 wrote:
| Is there just one set of switches? Or do both pilots have
| their own set?
| ExoticPearTree wrote:
| Only one set.
| KaiMagnus wrote:
| 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.
| creato wrote:
| Something like this could maybe happen to one switch,
| it's unlikely but possible. But two independent switches
| at the same time?
| KaiMagnus wrote:
| Good point, that is very unlikely. I was just wondering
| if it's possible at all.
| sugarpimpdorsey wrote:
| Those switches are the size of a thumb. No one is moving
| those - separately, mind you - and not realize what is
| going on.
| heisenbit wrote:
| The timing is really curious.
|
| 08:08:35 Vr
|
| 08:08:39 Liftoff
|
| 08:08:42 Engine 1 cut-off
|
| 08:08:42 Engine 2 cut-off
|
| 08:08:47 minimum idel speed reached
|
| ?? 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.
| cosmicgadget wrote:
| 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.
| XorNot wrote:
| Assuming the person trying to kill themselves and a plane
| load of people would respond in an expected way to
| inquiry is also just a mistake.
|
| It's not a rational decision, so there's no reason to
| expect rational decision making or explanation on the
| output.
| sugarpimpdorsey wrote:
| Too many are willing to accept the Bart Simpson excuse of
| "I didn't do it" at face value.
| ExoticPearTree wrote:
| > 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.
| leetrout wrote:
| > I would assume the captain
|
| The report states the FO was pilot flying.
| ExoticPearTree wrote:
| 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.
| magicalhippo wrote:
| 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.
| xenadu02 wrote:
| 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.
| rogerrogerr wrote:
| 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.
| Yokolos wrote:
| This makes me wonder. Is there no audible alarm when the
| fuel is set to cutoff?
| aerospace83 wrote:
| Armchair safety/human factors engineering, gotta love HN.
| zahlman wrote:
| 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.
| macintux wrote:
| 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.
| michaelmrose wrote:
| 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.
| sdgsdgssdg wrote:
| (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.
| dale_huevo wrote:
| 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.
| aerospace83 wrote:
| > That said Boeing could take a page out of the Garmin
| GI275
|
| This is not "reasoning from first principles". In fact, I
| don't think there is any reasoning in the comment.
|
| There is an implication that an obvious solution exists,
| and then a brief description of said solution.
|
| I am all for speculation and reasoning outside of one's
| domain, but not low quality commentary like "ugh can't
| you just do what garmin did".
|
| This is not a throwaway, I'm a lurker, but was compelled
| to comment. IMHO HN is not the place for "throwaway" ad
| hominems.
| Mawr wrote:
| > This is not "reasoning from first principles".
|
| 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.
| mitthrowaway2 wrote:
| 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.
| pixl97 wrote:
| When your engine catches on fire/blows apart on takeoff you
| want to cut fuel as fast as possible.
| OneMorePerson wrote:
| 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.
| p1mrx wrote:
| 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.
| lxgr wrote:
| 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.
| michaelmrose wrote:
| 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?
| 7952 wrote:
| 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.
| OneMorePerson wrote:
| 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".
| michaelmrose wrote:
| If engine_status == normal and last_activation greater
| than threshold time warn then shut off
|
| Else Shut off immediately End
|
| Override warning time by toggling again.
| SJC_Hacker wrote:
| 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.
| yard2010 wrote:
| 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.
| lazystar wrote:
| https://ad.easa.europa.eu/ad/NM-18-33
|
| 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
| barbazoo wrote:
| Same manufacturer, Air India 171 was a 787-8 though.
| shoghicp wrote:
| The affected table includes these models as well: 787-8,
| -9, and -10
| barbazoo wrote:
| Thanks for pointing it out.
| ggreer wrote:
| 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.
| lazystar wrote:
| 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.
| cosmicgadget wrote:
| Cutting fuel just after takeoff leaves almost zero time
| for the other pilot to recover.
| bombcar wrote:
| 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?
| cosmicgadget wrote:
| I think engine fires are still more common than suicidal
| pilots and inadvertant fuel shutoff activations.
| bombcar wrote:
| The idea would be something that is ONLY operational
| after V1 and until some safe height.
|
| Or maybe a design that prevents both switches being off
| (flip flop?) for X minutes after wheel weight is removed?
|
| Again, it's probably pointless but it's an interesting
| thought exercise.
|
| Suicidal pilots are apparently more common than we'd
| want.
| cosmicgadget wrote:
| The flip flop thing is a neat idea since a single engine
| can typically maintain level flight and two burning
| engines is rare.
| stephen_g wrote:
| 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.
| winter_blue wrote:
| 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.
| Scarblac wrote:
| Not AI, AI is less trustworthy than normal software
| almost by definition.
|
| Formally verified traditional algorithms.
| toast0 wrote:
| 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.
| dxdm wrote:
| > 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.
| bombcar wrote:
| 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 ...
| sugarpimpdorsey wrote:
| > My preliminary idea is a "fuel bladder" for take-off
| that inflates
|
| Will the bladder be marketed by Kramerica Industries?
| sitharus wrote:
| 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.
| 0_-_0 wrote:
| 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."
| Gare wrote:
| Well, AI is plain wrong. Fuel cutoff switches on Airbus
| are in the same position as in Boeing planes, below the
| throttle.
| sitharus wrote:
| And that's why you don't trust AI.
|
| 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.
| manquer wrote:
| it only guarantees an accident it doesn't guarantee death
| of the pilot, at such low altitude and speed anyone can
| survive as the one passenger did .
|
| Why would anyone risk potentially surviving a sabotage
| like that ?
| ggreer wrote:
| 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.
| somat wrote:
| 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?
| tekla wrote:
| They don't mention the locking mechanism being disabled
| cosmicgadget wrote:
| Is it easy to inadvertantly move both switches in such a
| scenario?
| lysace wrote:
| No.
| sandspar wrote:
| 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.
|
| Doing it accidentally is impossible.
| raphman wrote:
| Here's also a video showing operation of the switches:
| https://www.youtube.com/watch?v=33hG9-BCJVQ
| mdavid626 wrote:
| Well, can you move it back, when accidentally activated?
| joshAg wrote:
| 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__alchemist wrote:
| Yes, and it restarts the engines, but it takes on the order
| of seconds; too long at that altitude. One of the pilots
| did that, but it was too late.
| TylerE wrote:
| 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.
| alvah wrote:
| Turbines take a while to spin up again, it's not like
| start/stop in a car.
| stetrain wrote:
| 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.
| VBprogrammer wrote:
| In older turbine aircraft this would cause a hot start or
| worse. It would be interesting to know what the FADEC
| systems do in this case.
| sillysaurusx wrote:
| https://www.youtube.com/live/SE0BetkXsLg?si=LPss_su3PVTAqGCO
|
| 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.
| longos wrote:
| If this is what actually happened it would be the second in
| recent memory:
| https://en.wikipedia.org/wiki/Germanwings_Flight_9525.
| decimalenough wrote:
| Third, since there's no other plausible explanation for
| this and China has classified the report.
|
| https://en.wikipedia.org/wiki/China_Eastern_Airlines_Flig
| ht_...
| lanna wrote:
| Fourth? https://en.wikipedia.org/wiki/Malaysia_Airlines_F
| light_370#M...
| pineal wrote:
| Fifth. https://en.wikipedia.org/wiki/EgyptAir_Flight_990
| CBMPET2001 wrote:
| Sixth (and this one is pretty indisputable): https://en.w
| ikipedia.org/wiki/LAM_Mozambique_Airlines_Flight...
| ekianjo wrote:
| We dont know about that one at all.
| bdangubic wrote:
| we do here on HN :)
| lazystar wrote:
| 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.
| ekianjo wrote:
| without a black box all of this is supposition.
| lanna wrote:
| Hence the question mark
| VBprogrammer wrote:
| 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.
| chrisandchris wrote:
| > If it was an issue with the switches, we also would have
| seen an air worthiness directive being issued.
|
| I do not trust these air worthiness directives 100.0%. The
| 737 Max also required two catastrophic failures before it
| was grounded.
| decimalenough wrote:
| 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.
| sgt101 wrote:
| Absence of evidence isn't evidence of absence.
|
| 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.
| jon_smark wrote:
| 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.
| sgt101 wrote:
| For a long time my wife refused to accept that Tree
| Kangaroos existed and insisted that I'd made them up.
| When the internet came along she looked them up and
| treated me strangely for a while.
|
| What things that you have never seen do you not believe
| in?
| YeGoblynQueenne wrote:
| (not the OP) Giant isopods. They're not real. I know
| there are pictures of what are supposed to be giant
| isopods but they are not real animals, instead they're
| clearly fake models of made-up animals.
|
| Look at this:
|
| https://en.wikipedia.org/wiki/Giant_isopod#/media/File:Ba
| thy...
|
| Clearly some kind of plastic model. I mean _its eyes are
| gleaming menacingly_. Or look at this one:
|
| https://en.wikipedia.org/wiki/Giant_isopod#/media/File:Gi
| ant...
|
| Seriously, wikipedia? Seriously? That's clearly a hoax.
|
| Giant isopods are. not. real.
| YeGoblynQueenne wrote:
| A proof is a "piece of data"? Oh boy.
|
| https://en.wikipedia.org/wiki/Proof_theory
|
| https://en.wikipedia.org/wiki/Model_theory
|
| https://en.wikipedia.org/wiki/Mathematical_proof
|
| tl;dr: not a piece of data.
| jacquesm wrote:
| Yes, but things age. And as they age they can fail simply
| due to wear that wasn't determined to be a problem before
| they got to that point.
| 0_-_0 wrote:
| 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.
| briandear wrote:
| 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.
| cjrp wrote:
| The fuel cutoff switches are directly behind the
| throttles, in a central position. Maybe you're thinking
| of the stab cutout switches?
| blincoln wrote:
| This. There are no flip-covers on the switches in any of
| the photos I've seen. Additionally, it looks like the
| side guards are only on the left and right sides of the
| _pair_ of cutoff switches, not in-between the two
| switches. So if one bumped one switch, seems like it
| would be very easy to bump them both.
| rurban wrote:
| Only the captain was extremely experienced, the FO was a
| rookie. He wouldn't have had enough hours for an European
| airline
| jmtulloss wrote:
| This is not true at all.
|
| 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.
| fakedang wrote:
| He had 1100 hours on the 787 alone. 3200 hours
| altogether. Most media sources just went with the former
| figure as his overall experience.
| raverbashing wrote:
| 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
| briandear wrote:
| 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?
| raverbashing wrote:
| I love when people try to sound smart but instead they
| just prove their ignorance
| briandear wrote:
| 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.
| lupusreal wrote:
| 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.
| darth_avocado wrote:
| One would assume a toggle like that would come with blaring
| alarms and blinking lights... right? Right??
|
| Edit: It also seems like the engine cutoff is immediate after
| the toggle. I wonder if a built in delay would make sense for
| safety.
| lazide wrote:
| Low altitude, stall, and impact with terrain certainly
| will.
|
| And with how low and slow they were during takeoff, those
| would have been going off almost instantly.
| cjbprime wrote:
| > I wonder if a built in delay would make sense for safety.
|
| (Presumably delaying the amount of time before a raging
| engine fire stops receiving fuel would also have an impact
| on safety?)
| russdill wrote:
| 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
| 0_-_0 wrote:
| It could have been unimportant to them
| neuronic wrote:
| No it could not. Is your conclusion coming from a decade
| of piloting or maintaining commercial aircraft?
|
| If not, why are you speculating with zero knowledge?
| anonymars wrote:
| As hominem, did Captain Steeeeve's experience mean
| anything when he talked about the flaps?
| noduerme wrote:
| 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.
| JumpCrisscross wrote:
| One second. (Runway four is frequently zero four because
| radios.)
| mjevans wrote:
| 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.
| chgs wrote:
| If the time was :11 and :12 there's between 0.01 and 2
| seconds between. If they were both at :11 then it's
| between 0.01 and 1 second.
| bayesianbot wrote:
| Between (0, 2)s. Apparently the times are rounded down, so
| it could be :42.001 and :43.999, or :42.999 and :43.001
| rnd33 wrote:
| 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.
| sugarpimpdorsey wrote:
| Totally different airplane with a totally different flight
| deck, designed generations apart. The fact that the
| manufacturer is the same is irrelevant.
|
| You are trying to draw parallels between the ignition switch
| in a 1974 Ford Pinto and a 2025 Ford Mustang as if there
| could be a connection. No.
| sbuttgereit wrote:
| 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.
| dvh wrote:
| Entirely different kind of flying altogether
| briandear wrote:
| 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.
| ummonk wrote:
| 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.
| breadwinner wrote:
| > _post-flight muscle memory (of shutting off the engines)
| kicked in_
|
| Possible, and if so it is too early to conclude it was
| murder-suicide.
|
| See also: https://www.thehindu.com/news/national/dgca-
| slaps-80-lakh-fi...
| Jtsummers wrote:
| 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.
| alphabettsy wrote:
| that doesn't tell us they were fresh. Only that they
| hadn't flown. They could've slept 0 hours before or any
| number of things.
| moralestapia wrote:
| Sure, and aliens could also be involved.
|
| 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.
| whatevaa wrote:
| This is preliminary report. They will look deeper into
| this.
|
| Don't sentence people on unfinished investigations. This
| is why most trials are not public, because of people like
| you.
| moralestapia wrote:
| I'm glad you read my other comment [1].
|
| 1: https://news.ycombinator.com/item?id=44539508
| Dylan16807 wrote:
| > because of people like you
|
| No. Bad.
| svrtknst wrote:
| Aren't you the one building on suppositions? We know that
| they don't have flight hours. We cannot conclude what
| condition they were in aside from that.
|
| to jump from "they could be tired or hungover" to "yeah
| or aliens" is very dishonest. Especially for a very fresh
| matter where we know very little, all our assumptions are
| just that, and nothing we writes has any bearing on
| anything.
| fosk wrote:
| 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.
|
| https://generalaviationnews.com/2014/11/06/vanity-fair-
| the-h...
| 7952 wrote:
| 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.
| gosub100 wrote:
| > Murder-suicide looks like the likely conclusion
|
| But why cutoff the fuel instead of flying into terrain? It's
| such a passive action
| lotsofpulp wrote:
| I imagine it would be more difficult to fly into terrain
| without a cooperative co pilot than cutting the fuel just
| after take off.
| ummonk wrote:
| For whatever reason, the Egypt Air 990 pilot initiated his
| murder-suicide by pulling the thrust to idle and then
| flipping the fuel cutoff switches.
| bgwalter wrote:
| 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.
| tekla wrote:
| Yes there is.
| ssl232 wrote:
| > EDIT: Why is there no Cockpit Video Recorder? The days of
| limited storage are over.
|
| Pilots unions are dead against it.
| bombcar wrote:
| And now some pilots are dead.
|
| Just allow cockpit video recorders, and if they're ever
| used for anything, the pilots (or their heirs) get $250k in
| cash.
| gnulinux996 wrote:
| Are you actually using a tragedy like this to launch an
| assault on organized labour?
| JumpCrisscross wrote:
| Why is that outrageous?
| Dylan16807 wrote:
| What, do you want them to hem and haw and refuse to
| answer?
|
| Saying the union drove a decision is hardly "an assault
| on organized labor".
| yard2010 wrote:
| You have to admit this is a smart demagogue!
| ekianjo wrote:
| And Pilots end up dead because of it.
| nikanj wrote:
| 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.
| karlgkk wrote:
| 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
| ekianjo wrote:
| > Cost is a big one (satellite data is still quite a bit
| more expensive than you think, especially with many
| stations)
|
| You get free Starlink on several airlines now, so won't
| that be a solved problem soon?
| lxgr wrote:
| Free to passengers doesn't mean free to the airline, and
| Starlink in commercial airliners is very new.
| ekianjo wrote:
| sure but if the airline already pays for the service for
| passengers surely it can be used for the planes as well
| lxgr wrote:
| Not necessarily. Required certifications, SLAs etc. for
| safety critical systems are vastly different from those
| only handling passenger entertainment/connectivity. For
| example, Iridium has been around for almost 30 years now
| (launched in 1998), but it only became certified for
| safety of life applications at sea in 2019, and for
| aviation around 2010.
|
| Many planes still use completely separate systems for
| non-critical communication (often Ku or Ka band based
| geostationary satelliets) and for ATC or operational
| communication (usually L-band based Inmarsat or Iridium)
| as a result.
| lxgr wrote:
| 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.
| notahacker wrote:
| 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...
| Aeolun wrote:
| > 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.
| Dylan16807 wrote:
| 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.
| nikanj wrote:
| > Cost is a big one (satellite data is still quite a bit
| more expensive than you think, especially with many
| stations)
|
| I can pay $10 to have internet for the entire flight.
| Reasonably low bandwidth of course, but if I can splurge
| $10, the airline can.
| WalterBright wrote:
| 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.
| dcreater wrote:
| 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
| cosmicgadget wrote:
| Murder-suicide has happened on a few occasions. How many
| times has your malfunction occurred on an aircraft fuel
| system?
| bgwalter wrote:
| Not precisely the electrical malfunction, but dual engine
| shutdown has occurred, fortunately after landing:
|
| https://www.aerosociety.com/news/ana-787-engine-shutdown/
| cosmicgadget wrote:
| That doesn't seem to be a malfunction at all.
| shash wrote:
| Different engine (those are Trents and this was a GEnx),
| but yeah, that _did_ happen.
| stefan_ wrote:
| And then 10s later the switches magically fixed themselves?
| The likely not electronically connected switches since that
| would compromise engine redundancy?
| lazide wrote:
| The other pilot likely flipped them back - but at that
| point, it was impossible to avoid crashing.
| dcreater wrote:
| intermittent state switching is absolutely a thing in
| (poorly designed/manufactured/tested/QC'd) electronics
| pixl97 wrote:
| 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?
| userbinator wrote:
| All this rests on whether we have CVR audio of the pilot(s)
| manipulating the switches.
| ekianjo wrote:
| The rodents were remorseful and fixed the cables in the
| meantime. /s
| K0balt wrote:
| 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.
| dcreater wrote:
| > 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.
| pixl97 wrote:
| For both switches on seperate systems and wires that are
| independant.
|
| I mean, it's not impossible, but it sure the hell is
| improbable.
| postingawayonhn wrote:
| There is also audio of the pilots discussing the issue.
| __turbobrew__ wrote:
| 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.
| pigbearpig wrote:
| There are pictures of them in the report.
| userbinator wrote:
| 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.
| shash wrote:
| 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.
| ls-a wrote:
| So you're telling me that those switches don't have a voice
| that says "fuel cutoff switches transitioned" like in the
| movies? That's bad design
| yallpendantools wrote:
| 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.
| Mawr wrote:
| 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.
| ufmace wrote:
| 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.
| ls-a wrote:
| It's a joke about the design of safety systems involving
| actual human lives (movies being more safe). I get an
| audible warning on my laptop if i hit a key for too long
| for God's sake. These companies are a joke.
| yard2010 wrote:
| WHOOP WHOOP
|
| TERRAIN, TERRAIN! PULL UP! PULL UP! (WHOOP WHOOP)
| ls-a wrote:
| Wait till the final report is out and what resolution they
| come up with then we'll see who the joke is on
| Waterluvian wrote:
| 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.
| yardstick wrote:
| 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.
| ExoticPearTree wrote:
| There would have been an inaction on the part of the pilot
| that did this, but it is not mentioned in the CVR
| transcript.
|
| Hard to believe the other pilot wouldn't have said
| anything.
|
| Recovering the airplane and have some people survive the
| crash are two very different things.
| userbinator wrote:
| _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.
| crtified wrote:
| 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.
| shash wrote:
| 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_.
| crtified wrote:
| Any switch becomes moot if a saboteur has access to the
| behind-the-panel wires that the switch operates.
|
| But I presume that would leave physical evidence which
| would have been discovered by now. Presume, but cannot be
| certain.
| usefulcat wrote:
| 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.
| Epa095 wrote:
| 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.
| michaelmrose wrote:
| Are they looking at the physical switch or data about the
| state of the engine displayed in some other fashion?
| mrlongroots wrote:
| 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.
| userbinator wrote:
| Where can I listen to this recording?
| shash wrote:
| 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.
| groos wrote:
| 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.
| JSteph22 wrote:
| >mental fog, cognitive overload, wrong muscle memor
|
| 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.
| shawabawa3 wrote:
| This also makes sense with why nobody on the recording
| mentions re engaging the fuel switches
|
| The pilot denies shutting off the fuel, then realises he'd
| done it accidentally and quietly reenables them hoping
| there's enough time to save them
| cypherpunks01 wrote:
| Were the landing gear switches and fuel cutoff switches
| pretty close to each other here?
| raphman wrote:
| Not really. Landing gear switches are above the throttle
| between the screens1, fuel cutoff switches are below it2.
|
| 1) https://youtu.be/RbmFmWqqq0c?t=19
|
| 2) https://youtu.be/33hG9-BCJVQ?t=5
|
| (I'm not an expert, I just watched these videos)
| prepend wrote:
| 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."
|
| That person was really annoying.
| Aurornis wrote:
| 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.
| ionwake wrote:
| 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.
| YeGoblynQueenne wrote:
| Yeah, in the UK you lose your job when you make a fuss,
| not when you misbehave. That's my experience.
| WalterBright wrote:
| > It's difficult to conclude anything other than murder-
| suicide.
|
| Remember that incident where a cop pulled out his taser and
| tased the suspect? Except he pulled out his pistol and fired
| it.
|
| The taser looks nothing like a pistol, feels nothing like it,
| yet it is still possible to confuse the two in the heat of the
| moment.
| throwawaycan wrote:
| It's always easy in those threads to see who's familiar with
| the world of aviation and who's not.
|
| No it's not comparable to a cop that confuses things in the
| heat of the moment. Not anywhere close to be relatable.
|
| If it was, planes would be crashing down the sky quite often
| (and it would have been fixed for decades already).
| octo888 wrote:
| WalterBright is not totally unfamiliar with the aviation
| world...:
|
| > Bright is the son of the United States Air Force pilot
| Charles D. Bright
|
| > Bright graduated from Caltech in 1979 with a Bachelor of
| Science in Mechanical Engineering and a minor in
| Aeronautical Engineering
|
| > He worked for Boeing for 3 years on the development of
| the 757 stabilizer trim system
| nosianu wrote:
| 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.
|
| Location of the switches: https://media.cnn.com/api/v1/im
| ages/stellar/prod/c-gettyimag...
|
| Here is a video of a takeoff and climb in a 787:
| https://youtu.be/TTZozTaWiRo
|
| 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?
| WalterBright wrote:
| > Those switches cannot be accidentally flipped
|
| Yes, unbelievable things can happen. There are crashes
| where the pilot got discombobulated and a crash resulted.
|
| For another example, there are at least two crashes I
| recall (and I am sure there are many more) where the
| pilot pulled back to recover from a stall despite being
| trained endlessly to push forward to recover. (And they
| killed everyone on board.) Pilots get confused by what an
| alarm means, and do the wrong thing. Pilots assume the
| autopilot is on but they had accidentally turned it off.
| Sometimes people get crazy urges to do the wrong thing
| (there's a word for that: cacoethes).
|
| These things are rare, but when there are millions of
| flights, rare things happen.
| YeGoblynQueenne wrote:
| Interesting. "Cacoethes" means "malignant" in Greek. I
| didn't know the other meaning in English.
| yard2010 wrote:
| Also, a cop who can either read or write can't be expected to
| not make mistakes.
| lttlrck wrote:
| What were they confusing the switches with though? Are there
| two other switches they would be toggling at that phase?
|
| Perhaps they were very very confused and thought they had
| just arrived at the terminal?
| YetAnotherNick wrote:
| 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.
| refulgentis wrote:
| Free memento mori: you're both free-associating.
|
| 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_.
| Aeolun wrote:
| Using that reasoning all airplane crashes have a lot in
| common too.
|
| Doesn't mean the ones where you cannot determine the reason
| and have to speculate don't suck.
| refulgentis wrote:
| 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.
| Aeolun wrote:
| It means, sometimes the best you will get is speculation,
| because there's no definite answers to be had.
|
| E.g. it'd be nice if just hearing the CVR meant you knew
| the exact cause. Unfortunately not the case here.
| burnt-resistor wrote:
| > 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.
| epolanski wrote:
| 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.
| burnt-resistor wrote:
| 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.
| epolanski wrote:
| Forget my words then and take those from aviation
| experts.
|
| The fact that a pilot would cut off fuel from both
| engines, in sequence while taking off is virtually
| impossible to happen unless deliberate.
|
| Hence the hand brake comparison, it does not come natural
| to use it while driving.
| burnt-resistor wrote:
| 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.
| shawabawa3 wrote:
| Bare in mind there have been there have been what, 100+
| million flights? so "virtually impossible" things can,
| and will happen
| yread wrote:
| 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
| afro88 wrote:
| I pull my handbrake every time I park my car, but never
| mistake it for the windshield wiper while the car is
| moving
| sugarpimpdorsey wrote:
| > 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.
| burnt-resistor wrote:
| > cannot be mistaken for something else
|
| Assumption. Big ass assumption.
|
| 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.
| YuukiRey wrote:
| It's the explanation that requires the fewest
| explanations and assumptions I'd say.
| Aeolun wrote:
| > You don't know this.
|
| That it isn't certain doesn't change anything about it
| being pretty likely.
|
| Unpleasant, but I suppose at least it means we won't
| suddenly see other planes falling out of the sky due to
| fuel switches being set to off.
| Voloskaya wrote:
| > 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.
| jltsiren wrote:
| 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.
| agubelu wrote:
| Yet Occam's razor still applies
| jltsiren wrote:
| That's not what Occam's razor means. It means that after
| you have exhausted all options to rule out competing
| hypotheses, you choose the simplest one that remains, for
| the time being.
|
| Consider some explanations that are consistent with the
| evidence presented so far. And remember that the purpose
| of the investigation is to come up with actionable
| conclusions.
|
| 1. One of the pilots randomly flipped and crashed the
| plane for no reason. In this case, nothing can be done.
| It could have happened to anyone at any time, and we were
| extraordinarily unlucky that the person in question was
| in position to inflict massive casualties.
|
| 2. Something was not right with one of the pilots, the
| airline failed to notice it, and the pilot decided to
| commit a murder-suicide. If this was the case, signs of
| the situation were probably present, and changes in
| operating procedures may help to avoid similar future
| accidents.
|
| 3. One of the pilots accidentally switched the engines
| off. The controls are designed to prevent that, but it's
| possible that improper training taught the pilot to
| override the safeties instinctively. In this case,
| changes to training and/or cockpit design could prevent
| similar accidents in the future.
|
| Because further investigation may shed light on
| hypotheses 2 and 3, it's premature to make conclusions.
| manquer wrote:
| Given the fly by wire nature of 787 there is an also
| fourth option.
|
| The physical switch was not touched at all , and the
| software has a bug under some rare conditions which cut
| off the supply to both engines.
| neuronic wrote:
| The most likely scenario is not necessarily the truth. It
| still remains pure speculation and nothing else.
| ExoticPearTree wrote:
| > 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?
| decimalenough wrote:
| 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:
|
| https://www.youtube.com/live/SE0BetkXsLg?feature=shared
| ExoticPearTree wrote:
| 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?
| Aeolun wrote:
| > 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.
| ExoticPearTree wrote:
| > If we're talking about accidentally pressing buttons it
| seems we'd have seen incidents before.
|
| Well, of course I talk about an accidental touch of the
| wrong buttons.
|
| Flying is very safe, but at the same time, you will never
| know how many near misses happen daily that don't become
| accidents.
| bobsmooth wrote:
| Actually we do
| https://en.wikipedia.org/wiki/List_of_US_aircraft_near-
| miss_...
| ExoticPearTree wrote:
| Nice. But how about what happened in the cockpit that was
| never reported? Or something that was not seen by others?
| tiahura wrote:
| Have you ever turned your car off when you meant to turn on
| the windshield wiper?
| ExoticPearTree wrote:
| I turned off my car several times because I forgot I turned
| it on in the first place. In all fairness, it was always
| when I was parked.
| ssivark wrote:
| > _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.
|
| https://www.aviacionline.com/recommended-versus-mandatory-th...
|
| Per FAA the checks were recommended but not mandatory.
| moralestapia wrote:
| >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.
| michaelmrose wrote:
| Given the recent boundless incompetence by Boeing why not ask
| if their is any way for such to fail out of scope of the normal
| interface?
| card_zero wrote:
| 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.
| coolspot wrote:
| 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).
| card_zero wrote:
| OK, that makes a kind of sense, altitude would spoil the
| plan, if a suicidal pilot's only plan was to cut the
| engines.
| userbinator wrote:
| See Germanwings 9525 for an example of a conclusive suicide
| with no doubt from all the evidence.
| card_zero wrote:
| See me obliquely referencing that with "flying into the
| side of a mountain".
| Velorivox wrote:
| 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).
|
| [0] https://en.wikipedia.org/wiki/Yeti_Airlines_Flight_691
| procaryote wrote:
| 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.
| Simon_O_Rourke wrote:
| > 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.
| bob1029 wrote:
| > 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.
| ceejayoz wrote:
| I suspect any civil aviation engineer who goes "let's add
| hydrazine!" to fix problems has a fairly short career, lol.
| lazide wrote:
| Yeah, now you have _at least_ two problems.
| jeffrallen wrote:
| The prof from "chemicals I won't work with" has entered the
| chat...
| ExoticPearTree wrote:
| To my knowledge, hydrazine is extremely toxic. Most likely no
| regulator will allow it on commercial aircraft.
| SJC_Hacker wrote:
| The only solution I can think of is emergency parachutes. Like
| lots of them. would also be useful for other types of in air
| engine/control failures.
|
| At least it worked for me on Kerbal Space Program. At least
| sometimes.
| maxbond wrote:
| There's precedent.
|
| https://www.youtube.com/watch?v=2_8qCTAjsDg [30s]
|
| https://www.youtube.com/watch?v=zT58pzY41wA [15m]
|
| 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.
| burnt-resistor wrote:
| This is for a tiny aircraft, not a jumbo jet. SF50 and the
| Honda Jet can autoland too.
|
| Edit: I recently saw an SF50 YT video. It's pretty awesome
| with the V/X tail.
| burnt-resistor wrote:
| 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.
| dgunay wrote:
| This is an actual thing on smaller aircraft: https://en.m.wik
| ipedia.org/wiki/Cirrus_Airframe_Parachute_Sy...
| cpgxiii wrote:
| 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.
| interestica wrote:
| > at which point the aircraft will have "landed" one way or
| another.
|
| Ah
|
| Also we need more rocket thrust takeoff airplanes.
| burnt-resistor wrote:
| The RAT was already out and doing its job. Adding hydrazine or
| a nuclear reactor isn't going to help matters when there's no
| thrust.
| ChrisArchitect wrote:
| More discussion: https://news.ycombinator.com/item?id=44536691
| cosmicgadget wrote:
| The report says the co-pilot was flying so it's most likely the
| pilot cut the fuel?
| sillysaurusx wrote:
| Correct. Which means it's the older of the two.
| janice1999 wrote:
| The report does not identify which pilot said what.
| Attempting to extrapolate their identities is speculation.
| cosmicgadget wrote:
| The report specifically says the FO was flying. The
| conversation is immaterial since the person who cut the
| fuel could have made either statement.
| fsckboy wrote:
| 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.
| codefeenix wrote:
| even though that raising the gear is a up motion and fuelcut
| off is a down motion?
| rogerrogerr wrote:
| And fuel cutoff is _two_ down motions? That's the death knell
| for this theory, imo.
| fsckboy wrote:
| 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.
| WalterBright wrote:
| My editor is MicroEmacs, which I've been using since the
| 1980s. I no longer remember what the commands are, but my
| fingers do.
|
| I remember once writing a cheat sheet for the commands by
| looking at what my fingers were doing.
| Mawr wrote:
| > "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.
| zarzavat wrote:
| Would anyone be surprised if an accomplished concert
| pianist played C Bb Bb instead of C E in a piece they had
| played thousands of times correctly?
|
| The only difference here is that the consequences are death
| instead of mere head shaking.
|
| Murder needs more proof than just performing the wrong
| action. Until then we should apply Hanlon's Razor.
| Mawr wrote:
| 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.
| zarzavat wrote:
| 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.
| agubelu wrote:
| 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?
| rogerrogerr wrote:
| Another comment has the right analogy: has anyone here
| accidentally unplugged their mouse when they meant to hit
| caps lock?
| dyauspitr wrote:
| Sometimes I drive all the way home without being aware of
| what I did in between.
| adrianmonk wrote:
| 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.
| mcpeepants wrote:
| Is actuating the fuel cutoff switches something that is
| done routinely in these aircraft, to the extent it could
| reasonably become muscle memory?
|
| ETA: downthread it is mentioned that these switches are
| used on the ground to cut the engines
| abracadaniel wrote:
| Seems akin to something like a parking brake. Something
| you only use at a stop, or rarely during an emergency.
| card_zero wrote:
| Was amused to see they have one of those too, with
| "parking brake" written on it.
| fakedang wrote:
| 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.
| fsckboy wrote:
| 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
| russdill wrote:
| There is no possible way to confuse these two actions. There's
| a reason a wheel is attached to the gear lever.
| chmod775 wrote:
| Sometimes people put cleaning liquid in the fridge.
|
| Given a long enough span of time, every possible fuck up
| eventually will happen.
| dboreham wrote:
| Probably time to design a plane that can't be sent into
| terrain in seconds by flipping a switch.
| zamadatix wrote:
| "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.
| justsid wrote:
| Hilarious how Hacker News routinely bashes software
| managers who don't understand a problem space and give
| vague and impossible goals. But somehow "just don't let
| an aircraft fly itself into the ground" is a reasonable
| statement.
| sxg wrote:
| Now try to design a plane that also lets you rapidly
| shutoff fuel to both engines in case of fire.
| anonymars wrote:
| 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)
| Mawr wrote:
| 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...
| brookst wrote:
| Hey my car won't let me accelerate into a static object.
| It's so good it will even slam on the brakes when driving
| 5mph in a parking garage because it thinks parked cars
| are oncoming traffic.
| Mawr wrote:
| 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.
| interestica wrote:
| The _form_ of the action isn't necessarily what's stored.
| They may have memorized something as "fourth action" or
| some other mnemonic mechanism
| cjbprime wrote:
| > 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.
| bigDinosaur wrote:
| 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.
| globular-toast wrote:
| 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.
| eptcyka wrote:
| The only two production cars on sale where the steering
| wheel is mechanically decoupled from the wheels are the
| cybertruck and a variant of the Lexus RX.
| burnt-resistor wrote:
| Even humans have fixed action patterns. Much behavior is
| barely under conscious control.
| vishnugupta wrote:
| If I were to apply OPs assertion to your actions it's like
| brushing your teeth with razor. I guess that's what they
| meant.
| cjbprime wrote:
| 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.)
| russdill wrote:
| Neither is a toggle switch and the gear lever is
| incredibly conspicuous:
|
| https://www.aerosimsolutions.com.au/custom-
| products/olympus-...
|
| This would be like opening your car door when you meant
| to activate the turn signal.
| cjbprime wrote:
| I meant philosophical toggle switches, not physical ones.
| The gear can go between down and up. The fuel can go
| between run and cutoff. Given enough practice, the brain
| takes care of the physical actions that manipulate those
| philosophical toggles without conscious thought about
| performing them.
| Mawr wrote:
| 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.
| cjbprime wrote:
| Now I'm trying to remember if I've ever picked up my
| razor and accidentally begun tooth brushing motions with
| it. Probably!
|
| More relevantly, you seem to me to be unduly confident
| about what this pilot's associative triggers might and
| might not be.
| bapak wrote:
| 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.
| ninkendo wrote:
| I've definitely put shaving cream on my toothbrush
| before.
| mnahkies wrote:
| Not a bathroom one, but the number of times I've tried to
| pay for public transport with my work/office fob is
| mental. Generally happens on days where I'm feeling
| sharper than average but also consumed with problem
| solving
| bravesoul2 wrote:
| I agree. Has anyone here unplugged their mouse instead of
| pressing caps lock by mistake?
| interestica wrote:
| It depends on how that person internalized and learned
| the behaviour. We store things differently.
| uwagar wrote:
| this bathroom thing and various similar scenarios happens
| to me when im on weed.
| russfink wrote:
| 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.)
| wkat4242 wrote:
| They don't screen every time but there are spot checks. A
| pilot with heavy use will certainly get caught
| cjbprime wrote:
| The prelim report states these pilots were indeed
| breathalyzed before takeoff.
| 1970-01-01 wrote:
| Technically an overstatement but not by much. Correctly
| restated, its highly unlikely these actions were confusing
| pilots. It's as if you mistook flushing your toilet twice
| when instead you wanted to turn on the lights in your
| bathroom.
| cjbprime wrote:
| I don't agree with the "twice". A frequently performed
| manipulation like the fuel cutoff (usually performed
| after landing) collapses down to a single intention that
| is carried out by muscle memory, not two consciously
| selected actions.
| energy123 wrote:
| I want you to guess how many traffic accidents are caused by
| accidentally reversing when you intended to go forward.
|
| Test your mental model against the real world. This is your
| opportunity.
| Mawr wrote:
| 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.
| interestica wrote:
| You're just overlaying your mental model.
|
| 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)
| vachina wrote:
| Then that would be pilot error, and an aggravating error.
| bravesoul2 wrote:
| Driving isn't trained to anywhere near the same standard.
|
| Probably more training required to bake a cake than drive a
| car (hours wise).
|
| If we had your typical driver fly a plane we'd be doomed to
| a lot of crashes.
| malfist wrote:
| 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.
|
| Weird mistakes can happen.
|
| My partner got a good laugh out of it
| brookst wrote:
| Yep, I've taken clean dishes from the dishwasher and put
| them "away" in the refrigerator.
| kshacker wrote:
| As I get older, I do some similar stuff, way more than
| past, even it is just once per month. And I guess way more
| when sugar is high than not. Don't know your age or medical
| profile and I am not a doctor, just keep an eye.
| zamadatix wrote:
| 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.
| swores wrote:
| 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.)
| zamadatix wrote:
| Idle speculation is far from the only thing you won't find
| me supporting just because it's human nature. Thankfully,
| HN comment threads tend to include a lot more than just
| that kind of discussion, which is why I read them. Indeed
| there are lots of great details I didn't glean or fully
| understand in the report covered in the comments.
|
| That doesn't mean I will always agree with the comments (or
| that everyone will always agree with mine) and that's okay.
| It'd be a very limited value discussion if we could only
| ever comment when we agree. It seems exceedingly unlikely
| any of this has something to do with users being forced to
| be here though.
| sunnybeetroot wrote:
| They are a forum moderator and therefore it is part of
| their job, it is nice that you apologised.
| swores wrote:
| I... don't believe that's the case? Though happy to be
| proven wrong. Unless perhaps you mean a moderator of a
| different forum, though that wouldn't really be relevant
| to their reading a thread of HN comments on a subject
| that annoys them.
| sunnybeetroot wrote:
| You could be right and I'm getting confused with someone
| else. We will need to wait for them to confirm.
| mr_toad wrote:
| > If hearing those guesses annoys you, nobody is forcing
| you to read through comments on a thread of people making
| them!
|
| It'd be nice if we could only read insightful comments, and
| unread the wacko comments, but we can't. This discussion
| has actually provided a lot of useful comments from people
| who seem to know what they're talking about, but also a lot
| of really wild speculation.
| demondlee wrote:
| Double engine failure was confirmed, not disproven. RAT
| deployment was confirmed, not disproved. Pilot error,
| confirmed, not disproven. Preliminary and final aviation
| reports are mostly guesses.
| blincoln wrote:
| I don't think it's fair to say that pilot error is
| confirmed yet. It seems like a reasonable hypothesis, but
| what if the electronics glitched out and acted as though
| the cutoff switches had been flipped (the first time), even
| if they hadn't? All of the currently-disclosed facts still
| line up with that scenario IMO.
| mrlongroots wrote:
| Even as a matter of safety/investigation hygiene, "pilot
| error" should be the conclusion of last resort, arrived
| at after months of poring over data, and because nothing
| else seems viable.
|
| If we decided to pin all aviation incidents on pilot
| errors, we wouldn't even have invented checklists (what
| do you mean you forgot, try harder the next time).
|
| "Natural" pilot errors lead to lessons that can be
| incorporated into design/best practices. That does not
| seem to be the case given current understanding: no flaw
| in any switch design seems apparent, and it does not
| sound like something you could do by accident.
|
| So "pilot error" is not the "cracking the case"-grade
| conclusion it is being made out to be, it is an act of
| investigative resignation. In the days following the
| crash, allegations of mixing up flaps and landing gear
| were floated, and they all turned out to be wrong. This
| is not even accounting for the fact that the pilots are
| not around to plead their case, and basic human dignity
| requires us to defend their case until evidence clearly
| points a certain way
| nikcub wrote:
| > 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
|
| This was a really disappointing incident for aviation YouTube
| - I unsubscribed from at least three different channels
| because of their clickbait videos and speculation.
| 747fulloftapes wrote:
| 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.
| macintux wrote:
| > This idea strikes me as even more unlikely than someone
| shifting their moving vehicle into reverse while intending to
| activate the window wipers.
|
| I suspect you've never driven an older vehicle with the
| shifter on the steering column.
| ExoticPearTree wrote:
| > I suspect you've never driven an older vehicle with the
| shifter on the steering column.
|
| Or a new Mercedes ;)
| bravesoul2 wrote:
| But if he did, would have done hours of retraining in a
| simulator?
| losvedir wrote:
| Or a Tesla. I've done this exact thing, although the car
| just beeped at me and refused to go into reverse, of
| course.
| vachina wrote:
| The pilot wasn't flying an unfamiliar aircraft.
| ninkendo wrote:
| I think the aircraft being familiar makes it worse: if
| you're used to going through a certain motion to do a
| thing, it may be one of things your brain can do without
| really thinking about it much, which is where the danger
| comes in.
|
| I've engaged my wipers when meaning to shift gears
| before, in my truck which has a steering column shifter.
| After driving the truck for years. I have ADHD and I very
| often let my brain go on autopilot for things I do every
| day, and sometimes it just does the wrong thing. It
| doesn't matter how complicated or "intentional" the task
| has to be: my brain will memorize it to the point that it
| can execute it on its own without me consciously thinking
| about it.
|
| I think it's totally plausible it was a muscle memory
| thing, if the at-fault pilot's brain works anything like
| mine.
|
| (Side note: I actually took some flying lessons,
| including going through all of ground school, and
| realized that my brain is just not cut out for flying. I
| am the type of person to "cowboy" things if I feel like
| they're not worth doing, and flying is an activity where
| the tiniest missed checklist item can result in death, so
| I realized I have a statistically high likelihood of
| crashing due to some boneheaded mistake, and stopped
| taking lessons.)
| mr_toad wrote:
| If your wipers had the equivalent of a child safety cap
| it would be hard to do it accidentally, especially twice
| in a row.
| justsid wrote:
| But the 787 doesn't have an easily confused layout like
| that. The landing gear lever and fuel cut off switches are
| not two stalks on the yoke. Aircraft cockpits are
| deliberately designed in such a way that important things
| have differently shaped actuators that feel different from
| each other. Precisely so that you are not accidentally
| flipping the wrong switch by accident.
| jolt42 wrote:
| Actually the birth of Human Factors was related to
| this... Alphonse Chapanis, a psychologist working at the
| Army Air Force Aero Medical Lab in 1942, investigated the
| issue and discovered a design flaw. He observed that the
| controls for the flaps and the landing gear in the B-17
| cockpit were nearly identical and located close to each
| other.
| AdamN wrote:
| Or even crazier, a manual shift on the steering column.
| Nothing weirder than pushing down the clutch and then
| changing the gear with your hand on a knob off to the side
| of the steering wheel.
| YeGoblynQueenne wrote:
| Like in a Citroen 2CV?
| wkat4242 wrote:
| > It's very hard to mistake it for anything else. It's
| actuated by simply moving it up or down.
|
| On some aircraft types you also have to pull it towards you
| before moving it to avoid hitting it by mistake.
|
| But I agree it's very unlikely to be a muscle memory mistake.
| dyauspitr wrote:
| 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.
| WalterBright wrote:
| Consider a case where the engine starts to violently vibrate.
| This can tear the structure apart. Delaying shutting off the
| engine can be catastrophic.
|
| It's very hard to solve one problem without creating another.
| At some point, you just gotta trust the pilot.
| dyauspitr wrote:
| 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.
| WalterBright wrote:
| If the ground you are over is a good landing spot, your
| best chance is to cut off the fuel to that engine ASAP.
| dyauspitr wrote:
| All I'm saying is in those situations it should involve
| another toggle or pedal that needs to be pushed to cut
| off the engines so it's outside the realm of muscle
| memory.
| russdill wrote:
| 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
| jacquesm wrote:
| 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.
| interestica wrote:
| 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.
| WalterBright wrote:
| > The computer overrode the inputs.
|
| This is incorrect. The manual stabilizer trim thumb
| switches override MCAS.
| interestica wrote:
| Are we not in agreement? MCAS overrode the inputs and the
| thumb switches could override MCAS?
| hinkley wrote:
| Do you mean the MCAS System that sent two planeloads of
| people to their deaths?
|
| That MCAS system?
| bestouff wrote:
| On an Airbus yes, engines won't stop if the thrust lever
| isn't on "idle".
|
| Not so much on a Boeing.
| superasn wrote:
| 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?
| dubcanada wrote:
| 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.
| superasn wrote:
| Not sure why something so important isn't included.
|
| Heck they can make a back up directly to the cloud in
| addition to black box considering I'm able to watch YouTube
| in some flights nowadays.
| sokoloff wrote:
| ALPA (pilot union) has consistently objected to cockpit
| video recording. I believe other pilot unions have a
| generally similar stance.
| interestica wrote:
| 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.
|
| https://www.geaerospace.com/sites/default/files/enhanced-
| air...
| wkat4242 wrote:
| 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"
| bonoboTP wrote:
| 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".
| bgwalter wrote:
| Airlines would certainly try to surveil regularly, but if
| the video data is only sent to the sealed FDR, they'd
| need to tamper with the system.
|
| Additionally, footage could be encrypted with the NTSB
| having the keys.
|
| Or simply make it a crime to use the footage in non-
| accident situations (this should be applied to other
| forms of surveillance, too ...).
| sabujp wrote:
| If you work in a job where the lives of hundreds could be
| ended in seconds due to an error or intentional action
| then there is no excuse to _not_ have critical control
| surfaces recorded at all times. Non-commercial /private
| flights/flight instructors and trainees have cameras,
| trains have camera, stores have cameras, casinos have
| cameras, buses have cameras, workers who work for ride
| hailing services have cameras as do millions of other
| people who just drive.
|
| Hopefully other countries will start deploying recording
| systems or start forcing manufacturers of planes to have
| these integrated into cockpits.
| amelius wrote:
| My thoughts exactly.
|
| 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.
| curiousgal wrote:
| > _it makes sense to me that.._
|
| 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.
| briandear wrote:
| 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.
| 1over137 wrote:
| 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?
| inoop wrote:
| 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.
| TylerE wrote:
| No, no, and no.
|
| 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.
| seedless-sensat wrote:
| The landing great lever is shaped like a wheel as a design
| affordance. It would be VERY hard to confuse
| Rastonbury wrote:
| God knows the number of times I confused my num lock key
| for my caps lock key, they are both keys after all!
| demondlee wrote:
| Not possible. Two fuel cutoffs. Two engines. Two intentional
| acts in rapid succession. Plane would have survived one cutoff.
| It is what it appears. Captain crashed the plane.
| 1024core wrote:
| This photo: https://theaircurrent.com/wp-
| content/uploads/2025/07/ai-171-...
|
| from this article: https://theaircurrent.com/aviation-
| safety/ai171-investigatio...
|
| shows you the switches on a 787. They are protected and hard to
| futz around with by mistake.
| celsoazevedo wrote:
| Report mirror as the site seems to be down:
|
| https://celsoazevedo.com/files/2025/Preliminary_Report_VT_AN...
| comrade1234 wrote:
| Why can the pilot shut off the fuel during takeoff?
| jeffbee wrote:
| Suggest a system that would prevent this, but only this,
| without causing other risks.
| bob1029 wrote:
| 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.
| dboreham wrote:
| Sounds good, but I'm not sure I trust Boeing outsourced
| software developers to implement that absolutely correctly.
| yongjik wrote:
| 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.
| ExoticPearTree wrote:
| > 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.
| ufmace wrote:
| I don't think so. A moderately hard landing with an
| engine(s) smoldering because they were on fire but had
| their fuel cut off is probably survivable for most of the
| passengers. A moderately hard landing with the engine(s) a
| raging inferno pouring burning fuel all over the place
| because the fuel couldn't be cut off or took too long to do
| so is much less survivable.
|
| Putting complex and fallible restrictions on safety-
| critical controls like fuel cutoff is usually a bad idea
| overall.
| emmelaich wrote:
| At least an audible alert.
| anonzzzies wrote:
| Exactly
| wezdog1 wrote:
| Yeah that would have completed prevented this scenario /s
| MaKey wrote:
| Another comment mentioned that with an Airbus you first have
| to move the thrust lever to idle before you're able to cutoff
| the fuel.
| jeffbee wrote:
| That seems sensible and relatively easy to implement
| without screwing it up.
| baseballdork wrote:
| 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.
| dboreham wrote:
| I can't put my car into reverse gear while driving down the
| freeway.
| stetrain wrote:
| There's no good reason to do that.
|
| 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.
| arp242 wrote:
| You also can't reverse a plane while flying it...
|
| This is a rather odd comparison. You can slam the brakes,
| yank the steering week, and do all sorts of things to
| intentionally make the car crash.
| imoverclocked wrote:
| You can put the reversers on for a tactical descent
| though :P
| ExoticPearTree wrote:
| 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.
| sgentle wrote:
| 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.
| emmelaich wrote:
| On a Tesla (and presumably other cars) opening the door
| engages Park.
|
| There's no handbrake to pull, and turning the wheel so
| hard to lose control is next to impossible. _Maybe_ on an
| oily wet or loose surface.
| ExoticPearTree wrote:
| There are very few failure scenarios that are life
| threatening in a car.
| ojosilva wrote:
| 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.
| berti wrote:
| You can turn the ignition off. The reversers will not
| unlock on an airliner that's airborne either.
| WalterBright wrote:
| Remember the "surging" incidents where the driver insisted
| he was stepping on the brake but was actually stepping on
| the gas?
| yard2010 wrote:
| Remember when the driver pushed nothing but the tesla
| kept driving or braking?
| testing22321 wrote:
| 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.
| rhcom2 wrote:
| Completely uneducated guess but if one engine bursts into
| flames you might want to kill the fuel.
| lysace wrote:
| What you are really asking is: would we, the passengers, be
| safer without human pilots?
|
| Eventually, yes. Soon? Maybe.
| celticninja wrote:
| Dog and a pilot. The pilot is there to make sure everything
| is ok and the dog is there to bite the pilot if he tries
| touching anything
| bigbuppo wrote:
| 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.
| ExoticPearTree wrote:
| > Why can the pilot shut off the fuel during takeoff?
|
| Engine failure during takeoff.
|
| Engine fire.
| bigtones wrote:
| 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.
|
| https://www.nytimes.com/2025/07/11/world/asia/air-india-cras...
| callmeal wrote:
| 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.
| interestica wrote:
| https://ad.easa.europa.eu/blob/NM-18-33.pdf/SIB_NM-18-33_1
|
| > 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.
| labcomputer wrote:
| I'm sorry to tell you this, but that appears to be an AI
| hallucination.
|
| https://www.regulations.gov/document/FAA-2021-0273-0013
|
| None of the attachments reference the fuel cutoff switches.
| blincoln wrote:
| The peer comment to your own has a link to a real doc that
| supports the claim:
|
| https://ad.easa.europa.eu/blob/NM-18-33.pdf/SIB_NM-18-33_1
| apt-apt-apt-apt wrote:
| Even if the plane had no power, why couldn't they have glided it
| down safely?
| detaro wrote:
| how do you "safely" glide into a city?
| russfink wrote:
| 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.
| stetrain wrote:
| 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:
|
| https://www.theguardian.com/world/2025/jun/12/air-india-flig...
| appreciatorBus wrote:
| 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.
| WalterBright wrote:
| Speed can be traded for altitude, and altitude can be traded
| for speed. If you have neither, you're dead.
|
| Engine failure shortly after takeoff is a major cause of fatal
| accidents.
| burnt-resistor wrote:
| 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.
| 1970-01-01 wrote:
| 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.
| WalterBright wrote:
| Fire isn't the only instantly severe problem with engines.
| Another is violent shaking if, say, part of the rotating
| assembly came off.
| burnt-resistor wrote:
| 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.
| imoverclocked wrote:
| I'm not sure you want a creative AI flying a plane anyway.
| ExoticPearTree wrote:
| You can call it Schroedinger Airlines :))
|
| You may or may not reach your destination. Or something
| like that.
| burnt-resistor wrote:
| Just leave the door closed at all times, and then there's
| no definitive problem.
| burnt-resistor wrote:
| 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.
| yard2010 wrote:
| There is a visual cue in the case of fire so the pilot won't
| turn off the wrong engine.
| xyst wrote:
| A simple wrong flip of a switch killed 260 people and leaving 1
| lone survivor who walked away from the plane crash nearly
| unscathed.
|
| Dudes is extremely lucky or the character from Unbreakable.
| stetrain wrote:
| A flip of two switches, in sequence, with a locking mechanism
| on each switch.
| resist_futility wrote:
| In this YouTube short you can see the pilot switching both fuel
| cutoff to run
|
| https://www.youtube.com/shorts/bd4Bler36Nk
| deadbabe wrote:
| there's literally two other similar switches right next to
| those?
| resist_futility wrote:
| The switches on the lower panel that are switched, are the
| fuel cutoffs
| anonzzzies wrote:
| But they don't look protected or hard to switch?
| ojosilva wrote:
| 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.
| vishnugupta wrote:
| The pilot is toggling the switch on.
|
| Toggling it off presumably requires more power and is
| multiple actions.
| shash wrote:
| You move those switches down apparently. I don't think
| so.
| vishnugupta wrote:
| Up/Forward ==> Run ==> Fuel supply is on
|
| Down/Backwards ==> Cutoff ==> Fuel supply is off
|
| https://www.reddit.com/r/indianaviation/comments/1lxxatc/
| fue...
| shash wrote:
| I mean, there doesn't seem to be a different amount of
| force necessary.
| testrun wrote:
| They are hard to switch. You need to lift them to switch.
| Anishx7 wrote:
| 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
| sandspar wrote:
| All evidence suggests that the plane was fully functional. The
| switches were moved by one of the pilots.
| jeswin wrote:
| 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.
| testrun wrote:
| 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).
| shawabawa3 wrote:
| Are you sure there wasn't an audible alarm?
|
| 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)
| maxbond wrote:
| 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.
|
| Everyone survives - including the pilot.
|
| https://www.youtube.com/watch?v=rGwHWNFdOvg
|
| - 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.
|
| https://www.youtube.com/watch?v=pT7CgWvD-x4
|
| - 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.
|
| https://www.youtube.com/watch?v=DCMmCekKO_c
| notpushkin wrote:
| Mentour Pilot is a _fantastic_ channel.
| maxbond wrote:
| 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.
| padjo wrote:
| 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.
| HolyLampshade wrote:
| 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.
| anal_reactor wrote:
| Eh. His older videos are indeed phenomenal, but newer ones
| are "you won't believe what happened, right after this
| sponsor break"
| Mawr wrote:
| FUD. His videos are just as consistently good as they
| always have been. The sponsor sections can be easily
| skipped (hint: SponsorBlock).
| ekianjo wrote:
| still, its annoying and he does not need it either with
| the number of views he gets on Youtube.
| KronisLV wrote:
| I am not that person and can't talk about his finances,
| nor can you.
|
| If it's content I otherwise can enjoy for free, I don't
| mind sitting through a short sponsor spot every now and
| then, or just skipping through it if I'm in a hurry,
| which is still better than TV ads in that regard.
|
| If I saw something like that on a time sensitive video
| (e.g. proper CPR example) or something very short then
| I'd rightfully be upset, but this is not the case.
| xeonmc wrote:
| 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.
| anton-c wrote:
| Also green dot aviation has some great videos. Excellent
| animations. A calmer style. Both are great.
| tzs wrote:
| > 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.
| t0mas88 wrote:
| 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.
| someothherguyy wrote:
| > plug windows
|
| Surprisingly hard to search for this phrase
|
| This article covers the topic though:
|
| https://www.witpress.com/elibrary/wit-transactions-on-the-
| bu...
| throw310822 wrote:
| > the pressure difference at altitude works to hold the
| window in place
|
| Curious, is the pressure difference actually greater than the
| force of 800km/h wind pushing on the window? Or is it just
| for side windows?
| Rastonbury wrote:
| The outward pressure is about 5-6x greater than the force
| of air resistance at cruising altitude
| tzs wrote:
| Dynamic pressure of wind is 1/2 p v^2 where p is the air
| density and v is the velocity.
|
| At sea level p = 1.225 kg/m^3. It goes down as altitude
| goes up. At sea level the dynamic pressure at 800 km/hr
| would be about 4.4 PSI.
|
| At 20000 ft the air density is about half that of sea
| level, so around 2.2 PSI wind pressure. It would be around
| 1.4 PSI at 35k ft.
|
| At cruising altitude planes are typically about 8 PSI above
| the outside pressure.
|
| It would be maybe an interesting project for someone more
| ambitious then me to get a speed vs altitude profile of a
| typical airline flight and an altitude vs cabin pressure
| profile and figure at what part of a typical flight the
| screws on a plug window are resisting the most force.
| MangoToupe wrote:
| 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....
| bonoboTP wrote:
| 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.
| xeonmc wrote:
| Here's another one:
|
| Air Canada 143
|
| - 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.
|
| - No fatalties or serious injuries.
|
| https://www.youtube.com/watch?v=jVvt7hP5a-0
| interestica wrote:
| 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. "
|
| https://en.m.wikipedia.org/wiki/Gimli_Glider
| wkat4242 wrote:
| It's not an impossible maneuver. Glider pilots do this all
| the time especially if they don't have spoilers
| ExoticPearTree wrote:
| I would say it is much much harder. The wing configuration
| of an aircraft dictates the minimum glide speed. The more
| angled (for a better word) the wing, the higher the speed
| it needs to be at to be able to glide and not stall.
| kalenx wrote:
| Yes. On a plane which is designed to be a good glider. I
| highly doubt a 767 is designed to be a glider. It's
| definitely not impossible (after all, it was done
| successfully!), but certainly a very difficult (and
| undocumented) one on such a plane.
| foldr wrote:
| I don't think there's much connection between a plane's
| ability to do a sideslip and how well it glides. A
| sideslip is just what naturally happens if you apply
| opposite aileron and rudder inputs. I think the issue is
| just that it's a rather acrobatic maneuver to perform in
| a large passenger jet.
| efitz wrote:
| 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.
| padjo wrote:
| 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.
| throwawayben wrote:
| 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)
| padjo wrote:
| If the switches have an unknown design flaw then it's
| unknown how likely it is they'd both fail simultaneously
|
| My understanding is these switches are used routinely
| during the shutdown procedure or did I get that wrong?
| shawabawa3 wrote:
| These switches are used at the end of literally every
| flight
|
| The biggest problem with these theorising comment threads
| is the confidence people who know nothing about flying
| spout their theories
|
| (I know nothing about flying)
| efitz wrote:
| Muscle memory? That's grasping. How many times have you been
| pulling onto the highway and accidentally turned off your
| ignition?
|
| I'd buy "mechanical defect" if it was only one switch. Two?
| At the exact same time? During takeoff? Nope.
| sugarpimpdorsey wrote:
| Excellent analysis here, those switches are stout, no one is
| moving them by accident:
|
| https://www.youtube.com/watch?v=wA_UZeHZwSw
| callmeal wrote:
| Except when they are not:
|
| From the avherald link:
|
| >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.
| russdill wrote:
| 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"
| fakedang wrote:
| 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
| melenaboija wrote:
| 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?
| Yokolos wrote:
| Engine fire requires you to cut fuel to the affected engine.
| melenaboija wrote:
| Is cutting off fuel while taking off a better solution than
| letting them burn?
| cjbprime wrote:
| 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..
| labcomputer wrote:
| It is if you don't want the wing spar to fail!
| cco wrote:
| 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.
| xlbuttplug2 wrote:
| 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.
| nosianu wrote:
| > _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.
| xlbuttplug2 wrote:
| Okay, maybe there is little hope of making an ideal
| landing. But the likelihood of it being a fatal accident is
| significantly reduced without the building in the equation,
| no?
| jahewson wrote:
| Given the amount of fuel on board the answer is probably
| "not by much".
| bgnn wrote:
| Nope, the odds are pretty much the same, even on water.
| It helps to reduce the body count on the ground though.
| ipnon wrote:
| 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.
| bgnn wrote:
| This is true for boing, but not true dor Airbus design
| philosophy. Airbus tends to limit the pilot control inout
| pushing the plane out of safe operation conditions. I'm not
| sure of it's possible/not possible to cut the engine fuel
| supply during take-off in any Airbus though.
| bestouff wrote:
| Airbus liners don't allow cutting fuel with trust lever on.
| fosk wrote:
| This is actually very clever and elegant!
| labcomputer wrote:
| Well.. except that it means you can't turn off the engines
| if the throttle encoder fails.
| fosk wrote:
| Actually the parent comment was wrong:
|
| You can physically cut off fuel without pulling the
| thrust lever to idle, because the two are separate
| controls.
|
| However, it's against procedure to do so - even
| dangerous. Throttle should always be at idle before
| pulling the cutoff switch, because otherwise excessive
| pressure can be created in the fuel system.
|
| Essentially this is just a best practice, but there is no
| interlock between throttle and fuel cut off.
|
| Then I got intrigued by your comment in case the throttle
| encoder fails. Turns out there is double redundancy on
| the throttle encoder (if one computer fails, the next one
| takes over), and if both fail the airplane will run on
| the last known setting at which point the only possible
| action that can be taken is to cut off the fuel (or keep
| it running with the last known throttle level).
|
| In this regard both Boeing and Airbus follow the same
| implementation and there is no difference whatsoever
| between them.
|
| Perhaps something they I have learned is that cutting off
| fuel during max throttle position (take off) may have
| damaged the fuel system of the Air India airplane because
| of big pressure in the lines and that may have interfered
| with the restart of the engines when the fuel valve was
| opened again.
| imoverclocked wrote:
| I have to wonder how much more time they would have had if the
| landing gear had been retracted early since the gear adds a _lot_
| of drag.
| gethly wrote:
| It's simple - just don't fly Boeing - ever.
| timeon wrote:
| You know what? I'm just not going to fly - ever.
| bravesoul2 wrote:
| Your choice but safer to fly than drive the same journey.
| Commercial airliners anyway.
| anton-c wrote:
| 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.
| lambdaone wrote:
| You still have to rely on other drivers not being
| actually suicidal. Just to give one terrifying example
| scenario: you will pass hundreds, if not thousands of
| other drivers driving in the opposite direction in the
| course of a long journey. Any motorist driving in the
| opposing lane has the ability to engage other drivers in
| a head-on collision at any time by making a relatively
| trivial maneuver. Given human reaction times, and the
| very high closing velocity of such a collision, you
| ability to avoid this would seem to be non-existent. You
| certainly couldn't "just stop" to prevent it.
| m101 wrote:
| 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.
| chii wrote:
| 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.
| azan_ wrote:
| People do irrational things, especially if they are mentally
| unwell -
| https://en.wikipedia.org/wiki/Germanwings_Flight_9525
| bestouff wrote:
| There are already 5 other cases of pilot suicide with a full
| plane.
| franktankbank wrote:
| Look at financial motive. Some insurance payout stipulation
| or pension obligation to his family may have been boosted by
| death on the job.
| seydor wrote:
| So what's the status of full self driving airplanes (aka
| autopilot , or maybe autodriver to avoid the bad connotations)
| yard2010 wrote:
| It's a philosophical matter: even when we have self-driving
| cars boats and aeroplane a human should always make the final
| decision.
| richardatlarge wrote:
| 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
| nottorp wrote:
| Almost 400 comments and no avherald link for reference?
|
| https://avherald.com/h?article=528f27ec
| potamic wrote:
| > 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.
| bestouff wrote:
| Kneejerk patriotic reaction ?
| VBprogrammer wrote:
| 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.
| nottorp wrote:
| The way i read what avherald highlighted is that a part
| that the manufacturer said should be replaced wasn't and
| failed as the manufacturer said it will. So it would point
| to the airline maintenance right now.
|
| What the bbc says is truncated and omits the info about the
| failing part, so people can point towards murder suicide
| because they don't have all the info.
|
| Which is why you should always read avherald first...
| VBprogrammer wrote:
| The avherald is reporting second hand reports of the
| Indian media. The EEC MN4 microcontroller is located on a
| control board on each engine. A dual failure seems
| improbable.
|
| The fuel cutoff switches are of a similar design to the
| 737 and most other Boeing aircraft. A failure in that
| design seems less likely than the most charitable
| explanation, that the copilot inadvertently went into the
| wrong mode of muscle memory.
|
| The interim report does mention the SIAB NM-18-33. If you
| read that document it specifically says that the fuel
| cut-offs were installed with the locking feature
| deactivated on some 737 aircraft. It's a pretty big leap
| to that causing this incident. Someone or some thing
| would still need to have touched the switches to move
| them.
| manquer wrote:
| 10 years ago the dynamics could perhaps be as you sketched
| between regulators and the carrier but today it is more
| complex.
|
| Air India was government owned company till 2020s when it
| was sold back to the TATA group from whom it was originally
| nationalized from in the 1960s.
|
| Stakeholders like regulators, employees individually could
| have different PoV or interests in the change .
|
| Regulatory leadership could just as easily want to prove
| why this de nationalization was bad if so inclined as they
| could be for not wanting embarrass the flag carrier.
|
| So it would be hard to categorically say that regulator has
| vested interest in protecting the flag carrier
| labcomputer wrote:
| > 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).
| potamic wrote:
| There's also maintenance lapses, faulty repairs, defective
| parts, and as far as software goes I can think of n number
| reasons how a ghost can manifest itself inside program
| logic. This is a new gen plane that relies more on software
| than any other before, and has in fact seen a couple of
| incidents with loss of thrust, both related to software. I
| think it's more prudent to be asking hard questions around
| these than to outright dismiss it as an open and shut case.
| Besides, the murder/suicide angle is the least interesting
| outcome. Because there's nothing you can do after that,
| other than to just move on.
| agubelu wrote:
| Respectfully, media reports on what the investigation is
| focusing on should be taken with a grain of salt unless said
| media is known to be reputable and have credible sources.
|
| If they had a credible indication of a technical failure that
| causes engines to randomly shut down, they would have already
| grounded 787 fleets, which hasn't happened.
| narmiouh wrote:
| The one thing automatic system failure theory can't explain
| is whether there is a reverse connect from the machine back
| to the switches where if the machine decides to cut off fuel,
| would the physical switches toggle to cut-off or stay in run
| position while the fuel is actually cut off, this would
| require an actuator setup to flip the switches from inside
| the system which there is no documentation of if that is even
| support let alone reported?
| UltraSane wrote:
| 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.
| upcoming-sesame wrote:
| Is this really the reason they object video recording in the
| cockpit ?
|
| If so I agree it's not a good enough reason.
| yard2010 wrote:
| Please provide sources for your claims.
| UltraSane wrote:
| Which claim? It is self-evident that video footage would show
| if a pilot turned the engines off intentionally or
| accidentally.
|
| The pilot's union opposes cockpit video recording for silly
| reasons.
|
| https://www.ainonline.com/aviation-news/air-
| transport/2024-0...
| omnee wrote:
| 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.
|
| blancolrio puts its well:
| https://www.youtube.com/watch?v=wA_UZeHZwSw
| testemailfordg2 wrote:
| 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.
| AnonMO wrote:
| 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?
| bonoboTP wrote:
| > as the actions required take more than a second
|
| 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.
| rainsford wrote:
| > And the "I didn't do it" seems to be a lie.
|
| 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.
| rogerrogerr wrote:
| And there's motive to create misdirection: most life
| insurance policies have exclusions for suicide.
| ajross wrote:
| > the actions required take more than a second
|
| 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.
| CPLX wrote:
| > 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.
| hwillis wrote:
| 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.
|
| [1]:
| https://www.reddit.com/r/indianaviation/comments/1lxra3g/b78...
| dr_ wrote:
| 1) but what else would they say if they did do it?
| 18172828286177 wrote:
| 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.
| cjrp wrote:
| They could be close for retracting the flaps. Completely
| different control though.
| venusenvy47 wrote:
| If there was any worry that 787 switch lockouts are not working
| properly, wouldn't they release an immediate bulletin for
| inspections on all aircraft? It seems like the lack of any
| bulletins implies the lack of any suspicion on hardware
| problems.
| perihelions wrote:
| 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."_
|
| https://www.latimes.com/california/story/2023-10-24/off-duty...
| wkat4242 wrote:
| 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.
| wkat4242 wrote:
| 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...
| shash wrote:
| 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.
| dd_xplore wrote:
| 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.
| bonoboTP wrote:
| 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.
| CPLX wrote:
| 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.
| dr_ wrote:
| 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.
| SAI_Peregrinus wrote:
| Assuming this is a murder-suicide and not a mistake or
| malfunction somehow, it's _very_ damning of the FAA 's policy to
| revoke the pilot's licenses of anyone seeking treatment for
| mental health issues. This was in India and thus not FAA
| jurisdiction, but it still would be a case where an untreated
| mental health issue lead to hundreds of deaths. By making pilots
| choose between their careers & medical treatment (since they
| can't continue as pilots if they seek treatment) the FAA
| encourages hiding mental illness by pilots. The Pilot Mental
| Health Campaign[1] has been advocating for legislation to change,
| HR 2591 the "Mental Health in Aviation Act of 2025"[2] has just
| been approved by committee for a general vote. I certainly hope
| it passes, and that other nations with dangerous policies
| prohibiting pilots from seeking treatment change as well.
|
| [1] https://www.pmhc.org/
|
| [2]
| https://www.congress.gov/119/bills/hr2591/BILLS-119hr2591ih....
| breadwinner wrote:
| Wouldn't it be better to provide such pilots alternate career
| paths? That way they can still make a living and the traveling
| public is not placed under unnecessary risk.
| hollerith wrote:
| No, it is not damning evidence or strong evidence either way.
| It would be strong evidence only if treatment significantly
| reduces the probability of a pilot's committing suicide.
| tethys wrote:
| > if treatment significantly reduces the probability of a
| pilot's committing suicide
|
| Psychotherapy significantly reduces the risk of suicide.
| https://pmc.ncbi.nlm.nih.gov/articles/PMC6389707/
| varjag wrote:
| Does it bring the risk of suicide to general population
| baseline? And if not would you still want the affected
| people be responsible for hundreds of lives?
| cpncrunch wrote:
| >since they can't continue as pilots if they seek treatment)
|
| You have your facts wrong. Pilots can and do fly if they have
| mental health diagnoses, as long as they are well managed and
| there is no history of psychosis or suidical ideation. This is
| how it should be.
|
| https://www.faa.gov/ame_guide/app_process/exam_tech/item47/a...
| sillysaurusx wrote:
| On the contrary:
| https://youtu.be/988j2-4CdgM?si=G39BwNy1zJEeUi2k
|
| The whole reason a pilot made that video is because there's a
| huge problem in the airline industry right now.
| throw0101a wrote:
| Xyla Foxlin lost her PPL because her IUD was replaced, and
| how the new one (initially) released chemicals caused mood
| changes:
|
| * https://www.youtube.com/watch?v=aj0H8oVS7qg
| cpncrunch wrote:
| Looking at the transcript, it seems to confirm the link I
| posted, that there is a path back to flying, and that the
| FAA approves antidepressants.
| noqc wrote:
| The murder suicide angle isn't particularly worthy of
| _assumption_ yet. Have you ever put your phone in the fridge?
|
| Pilots deactivate the fuel cutoff at the end of the final taxi
| to the gate. This makes flipping these switches a _practiced
| maneuver_ , capable of being performed without conscious
| thought, regardless of whether they came with safety locks
| installed.
|
| Brain farts are a real phenomenon, and an accidental fuel
| cutoff most closely resembles the transcript from within the
| cockpit.
|
| The report is actually a little cagey about whether the locks
| were properly installed on these switches. Said locks are
| supposedly optional. Until I receive a more direct confirmation
| that the switches were installed with their full safety
| features, I will assume that it is more likely for the plane to
| have had improperly installed switches than not, given that the
| shutoff was the reason for the crash, and if they turn out to
| have been installed, I will assume that simple pilot error is
| responsible until a motive for murder is found. The pilots
| lives are under quite a lot of scrutiny, and I do not believe
| that a motive for murder is likely to be found.
| tim333 wrote:
| Turning the fuel off seems roughly equivalent to turning the
| ignition off when you've parked your car. It's really
| something rather unlikely to do as a brain fart during
| takeoff.
| sjsdaiuasgdia wrote:
| Most commercial aircraft have quite a few more buttons,
| knobs, levers, dials, etc than a car.
| jahewson wrote:
| Brain farts are literally not a real phenomenon.
| sillysaurusx wrote:
| If you were correct, the only situation it would happen in is
| when the pilot flying asks for X to happen, and the pilot
| monitoring instead does Y. Pilots don't just randomly reach
| over and screw with the controls. Everything is called out,
| and as far as I know there were no callouts here (e.g. "gear
| up").
|
| This is a bit like someone parking their car, pulling the
| handbrake, turning off the car and putting their keys in
| their pocket, then arguing that it's a practiced maneuver
| because it happens at the end of every car ride.
| histriosum wrote:
| > The report is actually a little cagey about whether the
| locks were properly installed on these switches. Said locks
| are supposedly optional.
|
| The locks/gates on the switches are definitely NOT optional.
| There was an SAIB about some switches that may have been
| installed improperly. It didn't result in an AD, which likely
| means the extent was limited or potentially even nil.
|
| The switches were moved to cutoff with a one second delay
| between the first and second switch. That's pretty suggestive
| of deliberate movement. I've flown a Max9 simulator, which
| has the same switches. Moving one of them by accident would
| be impossible, let alone two of them.
|
| I agree with not jumping to conclusions about the pilots and
| possible motives or circumstances, but I will bet a lot of
| money that the switches were just fine.
|
| The CVR will likely have audio of the switch movement to
| confirm as well.
| sillysaurusx wrote:
| First of all, thank you for calling attention to this. You're
| absolutely right, despite what others are saying here. That's
| why there's a movement for reforms.
|
| Secondly, yes, it was likely a deliberate action to cut off the
| fuel switches, as you say.
|
| You are absolutely right that there's an epidemic in the
| airline industry that forces pilots to stay quiet rather than
| risk their careers if they're dealing with mental health
| issues.
|
| In a sibling comment: "shouldn't they be given alternate career
| paths?" No. Perpetuating the myth that people with mental
| health issues are somehow broken beyond repair is mistaken.
| Current policy lead directly to that one fellow to lock the
| cockpit door and slam the plane into a hillside. If Air India
| 171 has any chance of being a mental health issue today, it
| should be highlighted and explored. You're exactly right to be
| doing that, and thank you.
|
| Anyone who disagrees with this should watch
| https://youtu.be/988j2-4CdgM?si=G39BwNy1zJEeUi2k. It's a video
| from a well-respected pilot. The whole point of the video is
| that aviation forces people to conceal their problems instead
| of seek treatment, and that this has to change.
| twoodfin wrote:
| For anyone who didn't already know, this concern is a key plot
| point in the second season of HBO's "comedy" series _The
| Rehearsal_.
|
| Personally, found it simultaneously one of the greatest and
| most insane seasons of television ever. YMMV.
| jeswin wrote:
| Here's another point of view:
| https://x.com/BDUTT/status/1944012769323626682
|
| The four Indian pilots on her show are clearly not convinced that
| the pilots are to blame.
|
| As they mention, it's important to know what else was spoken in
| the cockpit. Quite possible that there's more, and that might
| have implicated the pilots. However, if that's not the case, this
| is a very poorly worded report.
| ankit219 wrote:
| This is BBC, they have a history of being uncharitable when it
| comes to reporting on their erstwhile colonies. Jumping to a
| conclusion about pilot's fault when the recorded dialogues show
| both had no idea who cut it off (leaving ground for a
| possibility of some malfunction) is irresponsible, especially
| when the report could have been worded better without needing
| to reach a definitive conclusion.
|
| Both pilots have a long history of flying, a lot of experience,
| so while there is a chance one of them did it unknowingly, it's
| a small one in my opinion. Because it's not just a small
| switch, but a multi step procedure. The reporting on such a
| sensitive issue has been shocking to say the very least,
| whatever1 wrote:
| These airplanes reject a lot of the pilot inputs if they don't
| align with the expectations. Any idea why the system even allows
| the cut engine fuel input at that time of flight? Sounds to me
| that it should be just ignored. Even if both engines were on fire
| while climbing that early, what could cutting fuel offer?
| topbanana wrote:
| In case of engine fire they need to cut fuel
| whatever1 wrote:
| In general yes. But that early in the takeoff sequence
| cutting fuel will only kill you. If the engines can still
| provide thrust, I would take it.
| arctics wrote:
| Throttle control module (TCM) was replaced twice in the past 2019
| and 2023 which is not very usual.
|
| Now pure speculation, both pilots have long record of flying, you
| have to literally pull up and move each fuel control switches to
| cut off. Either one of the pilots did this intentionally or
| control unit was faulty. Considering past history and pilot
| experience, my bet is on faulty controls but we will never know.
| bgnn wrote:
| They can be tested if there's a mechanical failure ifthe
| switches survived the crash.
| wdb wrote:
| Wondering if it is save to fly with Air India at the moment
| yason wrote:
| It is known that the switches cannot effectively be flipped by
| accident.
|
| It is known that the switches were set to "cut-off" because they
| were then later restored to "run", so it was not an electrical
| fault (i.e. switches pointing to run but reporting cut-off).
|
| Pilot dialogue and engine telemetry confirms the cause of power
| loss was fuel cut-off.
|
| The question I can't help but think is how did the pilot realize
| it was the cut-off switches?
|
| I'm sure there's a warning message for them somewhere but in the
| few seconds of time when you're losing thrust right after rotate,
| and you're bombarded by a lot of warnings and errors on the
| screen and in the speakers: how likely are you to notice the fuel
| cut-off switches have been flipped?
|
| Those switches are something you never, ever think about during
| operation because you're trained to only operate them when
| starting up and parking (and yes, in an emergency where you need
| to shut down the engine quick).
|
| How long would it take for an average pilot to realize it's not
| one of the dozens of memory items pointing to more likely
| scenarios causing loss of thrust, ones that they've been training
| to check in case of an imminent emergency? And why didn't the
| first pilot who was recorded to notice the fuel cut-off didn't
| immediately flip the switches to "run" position first instead of
| asking the other pilot about it?
| hackrmn wrote:
| Given what you're vaguely implying -- that the switches would
| be nowhere near the first thing a pilot would normally think of
| in the kind of situation -- what are the odds the pilot asking
| on record "did you flip the fuel cut-off switch?" is the one
| who actually flipped the switches and was simply trying to fool
| the would-be investigation (even knowing they all are about to
| perish)?
| hexage1814 wrote:
| > what are the odds the pilot asking on record "did you flip
| the fuel cut-off switch?" is the one who actually flipped the
| switches and was simply trying to fool the would-be
| investigation (even knowing they all are about to perish)?
|
| This is such a diabolical mind-game that it never occurred to
| me. Like, they would all die, why would he want to
| incriminate someone else? But yet, people are weird and
| crazy. And maybe he didn't go down as a killer and decided to
| incriminate the other pilot? Anyway, it is totally possible
| to have happen. Sadly there are no cameras the cockpit, and a
| camera in the cockpit would really have help to find who did
| what.
| DebtDeflation wrote:
| I'd say the odds are 50%. The odds of the opposite scenario -
| where the pilot who said "did you flip the fuel cutoff"
| wasn't the one who did it are also 50%.
|
| Based on the cutoffs for both engines being flipped 1 second
| apart, the above exchange being caught on the CVR, and then
| within 10 seconds the (presumably the other) pilot switching
| them back to Run, it's pretty clear that this was a
| deliberate act.
| gmokki wrote:
| I would assume that the engines cur of due to fault in the
| shared control system. And to restore power the pilots toggled
| the switches to off and then back on to get them running again.
|
| Hopefully the timestamps tell if the engines lost power before
| switches were turned off? Or is there some time window that was
| not recorded due to the lost power to systems?
| blincoln wrote:
| This is one of the first scenarios that came to mind for me
| as well.
|
| i.e. hypothetically, no one flipped the switches to cutoff
| initially, but a glitch in a computer component caused the
| same effect, including some indication (a status light?) that
| the switches were in cutoff state. One of the pilots saw the
| indication, and asked the other. The other (truthfully) said
| they hadn't. Ten seconds of confusion later, one of them
| flipped the switches off and back on to reset the state to
| what it should have been.
|
| That assumes that the switches are part of a fly-by-wire
| system, of course. I am not an aircraft engineer, so maybe
| that's not a safe assumption. But if they're fly-by-wire,
| seems like there might not be a way to know for sure without
| cockpit video, because the logging system might only log an
| event when the switches cause the state to change from what
| the computer thinks the current state is, not necessarily
| when the switches change to the state the computer thinks
| they're already in.
|
| Someone bumping the switches accidentally seems worthy of
| investigation as well, given the potential for an "Oops! No
| locking feature! Our bad!" scenario on the part of Boeing
| that's mentioned in the BBC article.
| patch_cable wrote:
| I'm more familiar with the 737 (as a hobby, not as a pilot),
| but for that aircraft the "loss of thrust on both engines"
| checklist has the start levers as the second item on the list.
|
| Note that in the checklist I am looking at the goal is to
| restart the engines rather than diagnose the failure and that
| involves these levers. I suspect you'd notice pretty quickly if
| they were not in the expected location.
| yason wrote:
| Thanks, this is good information. So it then fits the overall
| picture that they would've actually bumped into these
| switches in the rush of emergency eventhough they're never
| expecting the switches to actually be off.
| mihaaly wrote:
| How can it be known that the switches were moved physically and
| not some electrical signal occured on its own (fault)
| equivalent of switches operated, without actual physical
| moement of the switch? Some electronic fault in the line of the
| signal. I do not expect having an independent sensor for this
| switch monitoring actual physical movements of the switch in
| parallel of the intended fuel controlling signals occurring, so
| the faulty signal reaching valves may have been registered and
| assumed that actual physical movement of the switch caused it?
| BurningFrog wrote:
| As an amateur UI designer I'm really surprised the plane allows a
| crash to be initiated without as much as an "Are you sure?"
| check.
|
| This is a completely computer run plane, and it surely has enough
| information to know this is a disastrous thing to do.
| stravant wrote:
| There's literally hundreds of such settings. When you get into
| the combinations there's such a multitude of scenarios that you
| certainly can't have dedicated code for everything.
|
| I suppose you could have it attempt to run a full forward-
| looking flight simulation to predict but part of the reason for
| there being so many controls is to deal with situations where
| the plane isn't acting like it should be, situations which
| would invalidate the simulation.
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