July 12, 2025, 19:08:00 GMT
permalink Post: 11920761
Can i respectfully suggest that an electrical fault causing these issues, given the enormous straw grasping that such a speculation requires (when taking into consideration elements we do know, from both the data feed and the CVR), should also fall into the bracket outlined in the first paragraph, as the odds of such an event still point us to the second paragraph..?
On reopening we've gone straight back into incredibly implausible (in my view so implausible as to be virtually impossible) around electrical faults and the hamster wheel of "does it record the electrical or the physical state".
Given what we do know, any conclusion other than someone physically moved the switches really requires evidence at this point rather than conjecture.
July 12, 2025, 20:28:00 GMT
permalink Post: 11920815
They don't have to be positively lifted if the detent rounded out due to wear or if the switch installed was one that the SAIB referenced with the locking feature disengaged. I can't discern a raised boss on the body of the left switch in Fig.13, page 10 of the AAIB report. I assume those switches have some internal over center locking mechanism also besides the spring on the lever that would not be needed if there was no detent. I do remember writing up a 767 switch a long time ago when the Captain noticed the detent was worn and he could shut down without lifting.
On the other hand pilots deciding to end their lives in a spectacular fashion is not inconceivable. In fact over the last 25 years it may be the single most numerous reason for a catastrophic loss of a transport category aircraft operated at a major airline.
July 12, 2025, 21:20:00 GMT
permalink Post: 11920840
I beg to differ: not from a pilot's point of view who didn't read the bulletin. Please see below about the recommended "tug".
Not a pilot, but electronics engineer here: I finally understood what's wrong with the "defective" switches: on such a switch, if you raise it up (to change its position) and you turn it slightly clockwise or counterclockwise before releasing it, it will operate normally, but the detents are now "crossing" the lock tab, and this one doesn't prevent a move-it-without-raising-it-first action anymore. As far as I can tell from the position of the switches, you have to extend your arm sideways and put some effort in your wrist to activate these switches: chances are that such a movement results in some amount of rotation.
Agreed, but this "test" won't tell you if the detents are aligned or misaligned with the lock tab.
If both switches are "defective" ones (remember, that doesn't mean they don't do their job, only that some specific action may put them in a state where protection against unwanted action is lost), the same action from the same pilot may well put both switches in the dangerous configuration.
By the way, I find that the "check" recommended in the bulletin for a switch suspected from being "defective" is incredibly misleading. It will possibly detect a switch where the cap has already been turned, resulting in a misalignment of the lock tab with the detents, but it won't detect a switch waiting for a turn to put it in the dangerous configuration. The "check" should be "pull on the cap to raise it, try to turn it clockwise or counterclockwise while raised: if it can be turned, it's defective".
On the contrary, according to the above scenario, anything interacting with the switches (which are close to each other) can move them unexpectedly (the "iPhone falling" case), and the CVR statement would reflect the surprise of a pilot who actually didn't do anything wrong.
May I add that I consider the probability of such a scenario as very very thin, but I wanted to emphasize the fact that we must keep our minds open, instead of jumping to conclusions too early.
Not a pilot, but electronics engineer here: I finally understood what's wrong with the "defective" switches: on such a switch, if you raise it up (to change its position) and you turn it slightly clockwise or counterclockwise before releasing it, it will operate normally, but the detents are now "crossing" the lock tab, and this one doesn't prevent a move-it-without-raising-it-first action anymore. As far as I can tell from the position of the switches, you have to extend your arm sideways and put some effort in your wrist to activate these switches: chances are that such a movement results in some amount of rotation.
It’s also the norm for everyone operating the switches to give them a tug to insure they are in the detents.
It’s simply inconceivable that both switches failed in exactly the same way at almost exactly the same time and no pilot who flew the aircraft in the last year or so noticed the issues.
By the way, I find that the "check" recommended in the bulletin for a switch suspected from being "defective" is incredibly misleading. It will possibly detect a switch where the cap has already been turned, resulting in a misalignment of the lock tab with the detents, but it won't detect a switch waiting for a turn to put it in the dangerous configuration. The "check" should be "pull on the cap to raise it, try to turn it clockwise or counterclockwise while raised: if it can be turned, it's defective".
Add to that the CVR statement and it’s beyond inconceivable.
May I add that I consider the probability of such a scenario as very very thin, but I wanted to emphasize the fact that we must keep our minds open, instead of jumping to conclusions too early.
July 12, 2025, 21:23:00 GMT
permalink Post: 11920843
What can be gleaned?
The fuel control switches were moved to cutoff…..or the signal said that they were, the result being the same.
Why is the subject of speculation.
The CVR transcript has not been fully released.
The World Wide 787 fleet has not been grounded.
GE are not under suspicion.
Crew actions are the likely cause.
The fuel control switches were moved to cutoff…..or the signal said that they were, the result being the same.
Why is the subject of speculation.
The CVR transcript has not been fully released.
The World Wide 787 fleet has not been grounded.
GE are not under suspicion.
Crew actions are the likely cause.
July 12, 2025, 21:43:00 GMT
permalink Post: 11920859
I beg to differ: not from a pilot's point of view who didn't read the bulletin. Please see below about the recommended "tug".
Not a pilot, but electronics engineer here: I finally understood what's wrong with the "defective" switches: on such a switch, if you raise it up (to change its position) and you turn it slightly clockwise or counterclockwise before releasing it, it will operate normally, but the detents are now "crossing" the lock tab, and this one doesn't prevent a move-it-without-raising-it-first action anymore. As far as I can tell from the position of the switches, you have to extend your arm sideways and put some effort in your wrist to activate these switches: chances are that such a movement results in some amount of rotation.
Agreed, but this "test" won't tell you if the detents are aligned or misaligned with the lock tab.
If both switches are "defective" ones (remember, that doesn't mean they don't do their job, only that some specific action may put them in a state where protection against unwanted action is lost), the same action from the same pilot may well put both switches in the dangerous configuration.
By the way, I find that the "check" recommended in the bulletin for a switch suspected from being "defective" is incredibly misleading. It will possibly detect a switch where the cap has already been turned, resulting in a misalignment of the lock tab with the detents, but it won't detect a switch waiting for a turn to put it in the dangerous configuration. The "check" should be "pull on the cap to raise it, try to turn it clockwise or counterclockwise while raised: if it can be turned, it's defective".
On the contrary, according to the above scenario, anything interacting with the switches (which are close to each other) can move them unexpectedly (the "iPhone falling" case), and the CVR statement would reflect the surprise of a pilot who actually didn't do anything wrong.
May I add that I consider the probability of such a scenario as very very thin, but I wanted to emphasize the fact that we must keep our minds open, instead of jumping to conclusions too early.
Not a pilot, but electronics engineer here: I finally understood what's wrong with the "defective" switches: on such a switch, if you raise it up (to change its position) and you turn it slightly clockwise or counterclockwise before releasing it, it will operate normally, but the detents are now "crossing" the lock tab, and this one doesn't prevent a move-it-without-raising-it-first action anymore. As far as I can tell from the position of the switches, you have to extend your arm sideways and put some effort in your wrist to activate these switches: chances are that such a movement results in some amount of rotation.
Agreed, but this "test" won't tell you if the detents are aligned or misaligned with the lock tab.
If both switches are "defective" ones (remember, that doesn't mean they don't do their job, only that some specific action may put them in a state where protection against unwanted action is lost), the same action from the same pilot may well put both switches in the dangerous configuration.
By the way, I find that the "check" recommended in the bulletin for a switch suspected from being "defective" is incredibly misleading. It will possibly detect a switch where the cap has already been turned, resulting in a misalignment of the lock tab with the detents, but it won't detect a switch waiting for a turn to put it in the dangerous configuration. The "check" should be "pull on the cap to raise it, try to turn it clockwise or counterclockwise while raised: if it can be turned, it's defective".
On the contrary, according to the above scenario, anything interacting with the switches (which are close to each other) can move them unexpectedly (the "iPhone falling" case), and the CVR statement would reflect the surprise of a pilot who actually didn't do anything wrong.
May I add that I consider the probability of such a scenario as very very thin, but I wanted to emphasize the fact that we must keep our minds open, instead of jumping to conclusions too early.
July 12, 2025, 21:51:00 GMT
permalink Post: 11920867
The fact the gear wasn't retracted is a clue. We don't yet have the full CVR but normally the PF would call for gear retraction.
The PNF (in this case the captain) responds by operating the CUT OUT switches from muscle memory.
He would have had to have been mentally checked out from his tasks as captain and PNF. Mental illness? Acute fatigue? Mental fog? Depression?
It's so hard to accept these switches were moved by one of the pilots just after liftoff.
The PNF (in this case the captain) responds by operating the CUT OUT switches from muscle memory.
He would have had to have been mentally checked out from his tasks as captain and PNF. Mental illness? Acute fatigue? Mental fog? Depression?
It's so hard to accept these switches were moved by one of the pilots just after liftoff.
July 12, 2025, 21:55:00 GMT
permalink Post: 11920870
A query, the FO was pilot flying and the Captain was pilot monitoring. Is it SOP that pilot flying sits in the LHS at takeoff? As I understand it the situation on power failure is that the battery backup will keep the displays alive until the APU comes online but only on the LHS. Trying to maintain best gliding performance and look for best landing site without any instruments to show speed or attitude would be more difficult. Captain taking over and swapping roles at 200 feet mid crisis is disruptive.
Tdracer has certainly explained that separation of cabling runs etc would have it very improbable that a single cable fault or short would impact both engines simultaneously in the same way. The CVR data is derived from local sensors with a dedicated battery backup, however all the FDR data and the fuel shut off commands are electrical signals which ultimately have a common source in the aircraft power buses. A water ingress into the EE bay at rotate which momentarily shorted all the low voltage buses to higher AC voltage is unlikely but is it unlikely to the same extent.
July 12, 2025, 22:46:00 GMT
permalink Post: 11920900
It seems to me that there must have been further dialogue after the bland "I didn't". To have nothing reported after that two-line exchange, until the MAYDAY at 08:09:05, is a highly suspect omission from the interim report. In a two-crew cockpit, facing a sudden dual engine rollback just after rotation, I find it very hard to believe that this two-line exchange was the only interaction captured.
Although published a little later than expected, it has now narrowed the speculator's focus from the wilder theories to the fuel switches.
Air India is not grounded, Boeing engines are not grounded and there are no recommended actions to engine operators and manufacturers.
Although a full verbatim transcript of the CVR could have been published, or even the recording itself, a decision has been made by the investigators not to do so. All we have is two bland paraphrases 'One of the pilots is heard asking the other why did he cutoff' (not even gramatically correct). 'The other pilot responded that he did not do so'.
Sometimes reports are more about what is not in them rather than was is in them.
It seems to me that the missing sections from the recording which would have revealed exact voice timings, language, tone, inflection and urgency which would have answered a lot of the questions on here have been deliberately withheld either temporarily or permanently. It is for the reader to infer why that might be. The investigators know much more but have chosen not to publicise it. I suspect they have more pieces of the jigsaw than we can see but probably not the full picture yet.
Last edited by T28B; 12th July 2025 at 23:06 . Reason: Formatting for ease of reading and pulling out key points
July 12, 2025, 23:05:00 GMT
permalink Post: 11920909
If it resulted in an eicas message, then the confused conversation, leading to (several) cycling attempts to reset them successfully to RUN, those 10 seconds later doesn\x92t sound unreasonable at all to me.
Not been in that situation, obviously, but I have certainly been in stressed situations where somewhere, someone (or something) pressed the wrong button, and I need to find out which one.
10 seconds is really not a long time if it is unexpected. It is very short.
Please also remember:
-We have no idea of exactly what was said. Whether the conversation referred to a error message, engines spooling down or physical switch movement/position. Throw in possible translation inaccuracies, and we can conclude even less from the information about the conversation, or what the level of clarity or confusion were.
-There is up to 2 seconds of margin of error in the time code of events because of the (speculated) sampling rate of 1Hz.
Not been in that situation, obviously, but I have certainly been in stressed situations where somewhere, someone (or something) pressed the wrong button, and I need to find out which one.
10 seconds is really not a long time if it is unexpected. It is very short.
Please also remember:
-We have no idea of exactly what was said. Whether the conversation referred to a error message, engines spooling down or physical switch movement/position. Throw in possible translation inaccuracies, and we can conclude even less from the information about the conversation, or what the level of clarity or confusion were.
-There is up to 2 seconds of margin of error in the time code of events because of the (speculated) sampling rate of 1Hz.
I'm talking about an electrical failure (for example a short), which is already implausibly affecting both (independent) circuits, causing an issue in a circuit that as I understand it fails open anyway, then resolving itself to become functional again - incidentally in roughly the same time frame that a pilot would notice an issue and seek to correct.
This doesn't require knowledge of the cockpit conversation or judgement on speed (or otherwise) of the recovery. It's purely that an already incredibly unlikely scenario (electrical failure) becomes even more unlikely with the spontaneous *and synchronised, but not perfectly so* removal of the fault state of whatever this failure was.
*Edit* Given my previous post has been removed it would appear that the mods also misread this to do with timing of *pilots response*, which I find a little odd as it was in response to a comment about electrical failure...
To be honest at this point for me we are immediately hamster wheeling again, and this time because any commentary around either electrical circuit issues (astronomical odds) or accidental device triggering cut off (no evidence nor can there be right now) are speculation in nature and have to be. Equally, while the obvious culprit is hands on the switches, any comments about why again are speculation and have to be.
There's nothing more anyone can get to on this one until further CVR data is released in my view. Bowing out.
Last edited by Mrshed; 12th July 2025 at 23:18 .
July 12, 2025, 23:06:00 GMT
permalink Post: 11920911
Tdracer has certainly explained that separation of cabling runs etc would have it very improbable that a single cable fault or short would impact both engines simultaneously in the same way. The CVR data is derived from local sensors with a dedicated battery backup, however all the FDR data and the fuel shut off commands are electrical signals which ultimately have a common source in the aircraft power buses. A water ingress into the EE bay at rotate which momentarily shorted all the low voltage buses to higher AC voltage is unlikely but is it unlikely to the same extent.
What bothers me is that message about the stab cutoff switches on the previous flight. It's a bit of a strange coincidence, since those switches are quite close to the fuel switches. I'm thinking that maybe some liquid could have been spilled during the previous flight over the area of the fuel switches and stab cutoff switches. Perhaps it initially affected just the stab switches. Then, during the accident flight, the acceleration and/or the rotation might have caused residual liquid to move and cause some issue for both fuel switches. Then, as the acceleration stopped after the loss of thrust and the aircraft stopped climbing, maybe the liquid moved again and the fuel switches recovered. But I admit this seems very unlikely.
July 12, 2025, 23:30:00 GMT
permalink Post: 11920926
No simulator access, but I do know this much:
One EICAS and one PFD is on the battery (most likely the left seat PFD) - they might momentarily flicker but will not 'blank'.
You get an EICAS message when you set the fuel switch to CUTOFF - something like "ENGINE X CUTOFF" (not sure of the 787 wording, but it would be something to that effect.
While I doubt the PF would be actively monitoring EICAS during TO, with the sudden audio change to the engine noise as well as the sudden loss of acceleration, I'd expect him to take a quick look at EICAS to see what the (
) the engines are doing. Plus, if the PF was in the right seat and his PFD blanked - I'd expect him to look across to see what's on either the standby or the left seat PFC, and perhaps EICAS.
One EICAS and one PFD is on the battery (most likely the left seat PFD) - they might momentarily flicker but will not 'blank'.
You get an EICAS message when you set the fuel switch to CUTOFF - something like "ENGINE X CUTOFF" (not sure of the 787 wording, but it would be something to that effect.
While I doubt the PF would be actively monitoring EICAS during TO, with the sudden audio change to the engine noise as well as the sudden loss of acceleration, I'd expect him to take a quick look at EICAS to see what the (
) the engines are doing. Plus, if the PF was in the right seat and his PFD blanked - I'd expect him to look across to see what's on either the standby or the left seat PFC, and perhaps EICAS.
CVR should have recorded the beeper too, inhibits are for ground only.
July 12, 2025, 23:46:00 GMT
permalink Post: 11920938
The preliminary report has provided sufficient information about what happened (in general terms). It has also explained what didn\x92t happen - and hence no need for an AD or groundings etc.
The information from the FDR is quite detailed. That from the CVR is conspicuously less so.
it has likely been decided that other investigative bodies need to be brought in to answer the who and why.
The information from the FDR is quite detailed. That from the CVR is conspicuously less so.
it has likely been decided that other investigative bodies need to be brought in to answer the who and why.
July 13, 2025, 00:27:00 GMT
permalink Post: 11920960
July 13, 2025, 03:02:00 GMT
permalink Post: 11920998
Basically, the preliminary report has narrowed down the cause of the disaster and discounted a few earlier theories such as flaps up instead of gear up, but there are a lot of questions still to be answered. We need to know; who, how and why.
The switches could have been set to cut off in error even though this was denied on the CVR. However anyone with experience in this part of the world knows that owning up to mistakes isn't a common practice.
I'd rule out a suicide attempt because if the pilot doing it had moved to switches to cut off and the other pilot had put them back on, a hard push forward on the control column at that height would have settled the matter.
I'm not yet convinced that the aircraft isn't responsible due to a technical fault or improper maintenance.
The switches could have been set to cut off in error even though this was denied on the CVR. However anyone with experience in this part of the world knows that owning up to mistakes isn't a common practice.
I'd rule out a suicide attempt because if the pilot doing it had moved to switches to cut off and the other pilot had put them back on, a hard push forward on the control column at that height would have settled the matter.
I'm not yet convinced that the aircraft isn't responsible due to a technical fault or improper maintenance.
July 13, 2025, 04:27:00 GMT
permalink Post: 11921012
I have only seen a diagram for I think the 737. I remember there being a listing of what each pole did, but I can no longer find the post.
My expectation/speculation, though, is this:
The EAFR gets its information on cutoff switch position from the FADECs via data buses, similar to almost all other engine data. We have N2 information in the report after the engines were switched off, so clearly there are no concerns about this data not being captured.
This means that the FADEC's data of where the switches are is almost certainly the EAFR's data.
There are other poles on the switches that do other things - I think it was opening/closing the LPSOV and enabling the generators. The fourth pole in the 'cutoff' position was IIRC not used because the generators don't get a disable signal, whereas the LPSOVs are powered open in the run position and powered closed in the cutoff position.
If the switches were physically operated and in good electromechanical condition (not counting the possibly faulty gates), we would expect all four poles to operate essentially simultaneously, with the four 'run' contacts opening and the four 'cutoff' contacts closing. Not only would the EAFR pick up that the FADECs were commanded off, but also that the LPSOV closes after a short delay, and the generators drop offline before N2 drops below idle.
When the switches are moved back to run, we would likewise see the position of each LPSOV return to open.
(this does not necessarily mean that a person intentionally operated them, but that the lever actually moved).
If there was a wiring fault, contamination, or internal switch failure, we would probably not see this. Instead, you might see the LPSOV remain open despite the engine shutting down, or perhaps the FADECs trying to keep the engine running while the LPSOV has closed and shut off fuel, or the two FADEC channels receiving different run/cutoff signals - and all of this would probably happen differently on each engine (if it affected both engines at all). There is no indication of this in the report.
These are not your basic light switch where the load is either powered or not powered. They're four switches ganged together and operated in unison, and each channel powers either thing A or thing B. If you have both or neither A & B powered (for longer than the ~50ms that the switch takes to move between positions), this is a fault that should be visible in the EAFR data in some/many cases. Think valves being displayed in orange as 'position unknown'.
If all run contacts opened, and all cutoff contacts closed, the switch moved from run to cutoff .
I don't know whether they analysed the EAFR data in this much detail yet, but coupled with a potential click sound on the CVR, I think there's going to be very very little doubt at the end of the investigation whether the switches physically moved or not, and I strongly expect they did.
July 13, 2025, 07:41:00 GMT
permalink Post: 11921093
What is an action slip?
There's a possible scenario we're discussing here that fits all of the available evidence. It proposes that one of the pilots operated the switches in an unconscious action called an "action slip". This is a rote action that we do without conscious thought when we're distracted: we mean to do something, and then we get our signals crossed and do something else. To learn more, search for "action slip" or "cerebellum" on this thread; I hope paulross adds the keyword to the next build of his excellent index at https://paulross.github.io/pprune-th...171/index.html .
How would this scenario play out?
We don't have enough evidence to pin down the exact sequence, so there are some assumptions here that I hope you find plausible. (And obviously it's not the only scenario that fits the evidence.) We especially do not know who did what and why, so that is all guesswork on my part. The times are taken from the preliminary report. The report places the verbal exchange among the pilots where I put it.
———
8:08:39 The 787 becomes airborne. The F/O is pilot flying (PF), with both hands on the yoke. The Captain is PNF (not flying).
8:08:42 The PNF unconsciously flicks both fuel switches to CUT OFF, one after the other. This is a rote action performed after each flight, or as training captain in the simulator.
The action cuts power to the engines; they stop delivering thrust almost immediately, and the turbines start slowing down.
The 787 systems disconnect the electrical generators in advance of them failing. The right side (Captain's side) of the cockpit loses power to most instruments. With all 4 generators offline, the RAT deploys to provide emergency power.
The PF feels the cessation of thrust. He looks at the display to see an ENGINES SHUT OFF message. He assumes the PNF shut them off, and asks him why he shut them off. This is the lowest "probe" level on the PACE assertiveness scale; see e.g. https://psychsafety.com/pace-graded-assertiveness/ or search for "probe alert" on pprune if you wish to know more. The highest level of assertiveness, E for "emergency", would have the F/O put the switches back himself immediately, but that would have required a high degree of confidence in the face of the older Captain that may have been difficult to achieve.
Since the action was unconscious, the PNF replies that he did not do that.
8:08:47 The RAT starts delivering hydraulic power, the engines decelerate past idle.
The PNF realizes that engine power is in fact cut. Eventually he checks the switches he thinks he did not touch, sees the engine 1 switch first and flips it back to RUN at 8:08:52. He then thinks to check the second switch and flips it up at 8:08:56.
The accident sequence ensues.
There's really not much the PNF can do at this point. At 8:09:05, he transmits a MAYDAY.
———
Obviously there are variations to this, for example it could have been the PF who put the fuel switches back. (In the above scenario, the PF is focused on flying—aviate!—and never turns his head to see the switches.) My goal was simply to set out a possible sequence, to see whether it feels plausible. Remember, as you see other scenarios put forth, that any issues a person could wrestle with would also be distracting. While both pilots would be very focused during the takeoff run, the moment the aircraft lifted off, the PNF could well have mentally relaxed a little, opening an opportunity for the action slip.
Thoughts?
There's a possible scenario we're discussing here that fits all of the available evidence. It proposes that one of the pilots operated the switches in an unconscious action called an "action slip". This is a rote action that we do without conscious thought when we're distracted: we mean to do something, and then we get our signals crossed and do something else. To learn more, search for "action slip" or "cerebellum" on this thread; I hope paulross adds the keyword to the next build of his excellent index at https://paulross.github.io/pprune-th...171/index.html .
How would this scenario play out?
We don't have enough evidence to pin down the exact sequence, so there are some assumptions here that I hope you find plausible. (And obviously it's not the only scenario that fits the evidence.) We especially do not know who did what and why, so that is all guesswork on my part. The times are taken from the preliminary report. The report places the verbal exchange among the pilots where I put it.
———
8:08:39 The 787 becomes airborne. The F/O is pilot flying (PF), with both hands on the yoke. The Captain is PNF (not flying).
8:08:42 The PNF unconsciously flicks both fuel switches to CUT OFF, one after the other. This is a rote action performed after each flight, or as training captain in the simulator.
The action cuts power to the engines; they stop delivering thrust almost immediately, and the turbines start slowing down.
The 787 systems disconnect the electrical generators in advance of them failing. The right side (Captain's side) of the cockpit loses power to most instruments. With all 4 generators offline, the RAT deploys to provide emergency power.
The PF feels the cessation of thrust. He looks at the display to see an ENGINES SHUT OFF message. He assumes the PNF shut them off, and asks him why he shut them off. This is the lowest "probe" level on the PACE assertiveness scale; see e.g. https://psychsafety.com/pace-graded-assertiveness/ or search for "probe alert" on pprune if you wish to know more. The highest level of assertiveness, E for "emergency", would have the F/O put the switches back himself immediately, but that would have required a high degree of confidence in the face of the older Captain that may have been difficult to achieve.
Since the action was unconscious, the PNF replies that he did not do that.
8:08:47 The RAT starts delivering hydraulic power, the engines decelerate past idle.
The PNF realizes that engine power is in fact cut. Eventually he checks the switches he thinks he did not touch, sees the engine 1 switch first and flips it back to RUN at 8:08:52. He then thinks to check the second switch and flips it up at 8:08:56.
The accident sequence ensues.
There's really not much the PNF can do at this point. At 8:09:05, he transmits a MAYDAY.
———
Obviously there are variations to this, for example it could have been the PF who put the fuel switches back. (In the above scenario, the PF is focused on flying—aviate!—and never turns his head to see the switches.) My goal was simply to set out a possible sequence, to see whether it feels plausible. Remember, as you see other scenarios put forth, that any issues a person could wrestle with would also be distracting. While both pilots would be very focused during the takeoff run, the moment the aircraft lifted off, the PNF could well have mentally relaxed a little, opening an opportunity for the action slip.
Thoughts?
Seeing that the gear remained down after liftoff, there was CVR confusion after the event, and there was an attempt to rectify the situation…. I’m now thinking aviation is witnessing its most bizarre action-slip it’s ever seen and we’ll learn that the human automatic system is capable of making the most inappropriate and illogical responses to a given situation. I suspect fatigue and the captains sim experience of flicking switches plays a part.
As a result of this, I think we’ll see a renewed interest in slowing down actions at all times…touch a control, look at it, pause, consciously think about what you are touching before you execute it. This needs to be habitual, especially on LH fleets where fatigue inevitably plays into the operation.
We’ll also be discouraging the “insta-pilot” trend of showing how slick you are (usually on A320) where your hands flick round the flight deck at lightning speed. Even in more benign scenarios like shutdown flows etc, this isn’t a good habit.
July 13, 2025, 07:45:00 GMT
permalink Post: 11921095
Why don't they publish CVR recordings?
The short answer is that we wouldn't have CVR recordings if that was possible.
Basically, the cockpit voice recorder records the pilots incriminating themselves. It was only possible to get pilots to agree to have a CVR in the cockpit by assuring them it would only be used in accident investigations. For example, on the 787's EAFR you can read out the data on a laptop connected to the onboard network, but you can't read out the CVR unless you physically access the device.
Air accident investigations must safeguard that status. Their success depends on the guarantee that the investigation results can't be used to incriminate the pilots legally. But while courts cannot subpoena the CVR recording from the accident investigation, they wouldn't have to if the board released a full recording or even just a full transcript.
In my opinion, that is why this preliminary report is vague on who said what, and what exactly was said.
The CVR must not become a constant "anything you say can and will be used against you in a court of law" in the cockpit.
I'd be happy if any lawyers in the thread (e.g. WillowRun 6-3 ) could correct or confirm.
Basically, the cockpit voice recorder records the pilots incriminating themselves. It was only possible to get pilots to agree to have a CVR in the cockpit by assuring them it would only be used in accident investigations. For example, on the 787's EAFR you can read out the data on a laptop connected to the onboard network, but you can't read out the CVR unless you physically access the device.
Air accident investigations must safeguard that status. Their success depends on the guarantee that the investigation results can't be used to incriminate the pilots legally. But while courts cannot subpoena the CVR recording from the accident investigation, they wouldn't have to if the board released a full recording or even just a full transcript.
In my opinion, that is why this preliminary report is vague on who said what, and what exactly was said.
The CVR must not become a constant "anything you say can and will be used against you in a court of law" in the cockpit.
I'd be happy if any lawyers in the thread (e.g. WillowRun 6-3 ) could correct or confirm.
July 13, 2025, 07:47:00 GMT
permalink Post: 11921097
I\x92m 100% with you on this. Back on the original thread, whilst everyone was distracted by some extremely unlikely technical scenarios, I\x92d predicted that although it was unthinkable, the most likely cause was manually switching both fuel control switches\x85
Plane crash near Ahmedabad..
Seeing that the gear remained down after liftoff, there was CVR confusion after the event, and there was an attempt to rectify the situation\x85. I\x92m now thinking aviation is witnessing its most bizarre action-slip it\x92s ever seen and we\x92ll learn that the human automatic system is capable of making the most inappropriate and illogical responses to a given situation. I suspect fatigue and the captains sim experience of flicking switches plays a part.
Seeing that the gear remained down after liftoff, there was CVR confusion after the event, and there was an attempt to rectify the situation\x85. I\x92m now thinking aviation is witnessing its most bizarre action-slip it\x92s ever seen and we\x92ll learn that the human automatic system is capable of making the most inappropriate and illogical responses to a given situation. I suspect fatigue and the captains sim experience of flicking switches plays a part.
Even Indian sources are now reporting on the possibility of intent.
https://www.ndtv.com/india-news/air-...-probe-8864239
July 13, 2025, 08:33:00 GMT
permalink Post: 11921133
The short answer is that we wouldn't have CVR recordings if that was possible.
Basically, the cockpit voice recorder records the pilots incriminating themselves. It was only possible to get pilots to agree to have a CVR in the cockpit by assuring them it would only be used in accident investigations. For example, on the 787's EAFR you can read out the data on a laptop connected to the onboard network, but you can't read out the CVR unless you physically access the device.
Air accident investigations must safeguard that status. Their success depends on the guarantee that the investigation results can't be used to incriminate the pilots legally. But while courts cannot subpoena the CVR recording from the accident investigation, they wouldn't have to if the board released a full recording or even just a full transcript.
In my opinion, that is why this preliminary report is vague on who said what, and what exactly was said.
The CVR must not become a constant "anything you say can and will be used against you in a court of law" in the cockpit.
I'd be happy if any lawyers in the thread (e.g. WillowRun 6-3 ) could correct or confirm.
Basically, the cockpit voice recorder records the pilots incriminating themselves. It was only possible to get pilots to agree to have a CVR in the cockpit by assuring them it would only be used in accident investigations. For example, on the 787's EAFR you can read out the data on a laptop connected to the onboard network, but you can't read out the CVR unless you physically access the device.
Air accident investigations must safeguard that status. Their success depends on the guarantee that the investigation results can't be used to incriminate the pilots legally. But while courts cannot subpoena the CVR recording from the accident investigation, they wouldn't have to if the board released a full recording or even just a full transcript.
In my opinion, that is why this preliminary report is vague on who said what, and what exactly was said.
The CVR must not become a constant "anything you say can and will be used against you in a court of law" in the cockpit.
I'd be happy if any lawyers in the thread (e.g. WillowRun 6-3 ) could correct or confirm.
I understand, to some extent, the reasoning for not publishing the actual recording as a general rule, but from my perspective the usual outcome is speculation that can be just as critical of the actions and skills of the crew, and be just as inviting to 'ambulance chasers' keen on litigation, as ripping the band aide off the sore and dealing with the truth. I remain of the view that the least bad way to get to the awful truth - whatever it may be in the circumstances of this tragedy - includes publication of the raw recordings of the cockpit and ATC. As many have already pointed out - correctly in my view - so much depends on the nuances of the language spoken, who said what, in what order, the cultural or other status of those in the conversation, the other sounds in the environment, all assessed in the context of the timeline of flight data recorded.
All one needs to do is consider the different meanings of "yeah nah" or "yeah right" in the Australian vernacular, which meanings depend, crucially, on context and tone and inflection and emphasis. Without that level of detail, paraphrasing or even quotes in transcripts are more often the source of increased speculation rather than the resolution of uncertainty.
July 13, 2025, 08:38:00 GMT
permalink Post: 11921140
When does the CVR start on a 787 ?