July 12, 2025, 07:28:00 GMT
permalink Post: 11920280
It's established fact both fuel control switches moved to CUTOFF 4 seconds after Vr, a deliberate guarded action, not easily done accidentally.
The CVR records one pilot asking “Why did you cut off?”, the other replies “I didn’t”. Then a bland Mayday attributed to the Captain “engine failure, returning” in the middle of the crisis.
The language, if reported correctly, feels strangely detached. No confusion, no urgency, no clear troubleshooting. Not drawing conclusions, but does anyone else see signs of performative behaviour, that is saying the right things outwardly, while being at odds with the underlying cause?
I appreciate that both crew members lost their lives, however if we avoid discussing uncomfortable patterns, we miss the point of investigation and learning.
The CVR records one pilot asking “Why did you cut off?”, the other replies “I didn’t”. Then a bland Mayday attributed to the Captain “engine failure, returning” in the middle of the crisis.
The language, if reported correctly, feels strangely detached. No confusion, no urgency, no clear troubleshooting. Not drawing conclusions, but does anyone else see signs of performative behaviour, that is saying the right things outwardly, while being at odds with the underlying cause?
I appreciate that both crew members lost their lives, however if we avoid discussing uncomfortable patterns, we miss the point of investigation and learning.
July 12, 2025, 07:42:00 GMT
permalink Post: 11920296
Timeline of known events with source attribution from the preliminary report:
08:07:33 ATC: Takeoff clearance
08:07:37 A-SMGCS: Aircraft starts rolling
08:08:33 EAFR: V1 153kts
08:08:35 EAFR: Vr 155kts
08:08:39 EAFR: Gnd-Air mode transition
08:08:42 EAFR: Max IAS 180kts, Eng 1/2 Cutoff switches activate within 1 second of each other
08:08:42 CVR: "Why did you cut off", "I did not" (exact time not specified)
08:08:42 A-SMGCS: RAT deployed (exact time not specified)
08:08:47 EAFR: Both engine N2 below min idle. RAT hyd pwr commences
08:08:52 EAFR: Eng 1 cutoff to RUN
08:08:54 EAFR: APU inlet door opens (auto start logic)
08:08:56 EAFR: Eng 2 cutoff to RUN
08:09:05 ATC: Mayday call
08:09:11 EAFR recording stops
Fuel cutoff switches operated within 1 second of each other suggests to me that the locking mechanism wasn't working as per (SAIB) No. NM-18-33. Any loose item could have accidentally (or not) operated the switches (including hands).
08:07:33 ATC: Takeoff clearance
08:07:37 A-SMGCS: Aircraft starts rolling
08:08:33 EAFR: V1 153kts
08:08:35 EAFR: Vr 155kts
08:08:39 EAFR: Gnd-Air mode transition
08:08:42 EAFR: Max IAS 180kts, Eng 1/2 Cutoff switches activate within 1 second of each other
08:08:42 CVR: "Why did you cut off", "I did not" (exact time not specified)
08:08:42 A-SMGCS: RAT deployed (exact time not specified)
08:08:47 EAFR: Both engine N2 below min idle. RAT hyd pwr commences
08:08:52 EAFR: Eng 1 cutoff to RUN
08:08:54 EAFR: APU inlet door opens (auto start logic)
08:08:56 EAFR: Eng 2 cutoff to RUN
08:09:05 ATC: Mayday call
08:09:11 EAFR recording stops
Fuel cutoff switches operated within 1 second of each other suggests to me that the locking mechanism wasn't working as per (SAIB) No. NM-18-33. Any loose item could have accidentally (or not) operated the switches (including hands).
Last edited by sorvad; 12th July 2025 at 08:03 . Reason: Clarification
July 12, 2025, 10:43:00 GMT
permalink Post: 11920473
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.
July 12, 2025, 11:36:00 GMT
permalink Post: 11920539
It's established fact both fuel control switches moved to CUTOFF 4 seconds after Vr, a deliberate guarded action, not easily done accidentally.
The CVR records one pilot asking \x93Why did you cut off?\x94, the other replies \x93I didn\x92t\x94. Then a bland Mayday attributed to the Captain \x93engine failure, returning\x94 in the middle of the crisis.
The language, if reported correctly, feels strangely detached. No confusion, no urgency, no clear troubleshooting. Not drawing conclusions, but does anyone else see signs of performative behaviour, that is saying the right things outwardly, while being at odds with the underlying cause?
I appreciate that both crew members lost their lives, however if we avoid discussing uncomfortable patterns, we miss the point of investigation and learning.
The CVR records one pilot asking \x93Why did you cut off?\x94, the other replies \x93I didn\x92t\x94. Then a bland Mayday attributed to the Captain \x93engine failure, returning\x94 in the middle of the crisis.
The language, if reported correctly, feels strangely detached. No confusion, no urgency, no clear troubleshooting. Not drawing conclusions, but does anyone else see signs of performative behaviour, that is saying the right things outwardly, while being at odds with the underlying cause?
I appreciate that both crew members lost their lives, however if we avoid discussing uncomfortable patterns, we miss the point of investigation and learning.
July 12, 2025, 19:21:00 GMT
permalink Post: 11920769
I don\x92t know if the FDR measures the switch position or the electrical signal. The latter is probably more likely, although there has been much discussion around potential scenarios involving accidental switch movement as well as possible causes of electrical glitches. Let\x92s assume that the switches were actually moved, and ignoring the \x93bad faith\x94 scenario, we need a situation that encompasses the switches being moved to Cutoff by one pilot, this action being queried by the other pilot and denied by the pilot who moved the switches.
For consideration, here is a possible scenario that hasn\x92t been mentioned yet and encompasses the frailty of human performance. The report mentions that the flight crew on the immediately prior flight had written up a "STAB POS XDCR" status message, and that troubleshooting was carried out. I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead. As in all modern Boeings, the Stabiliser Cutoff switches are immediately next to the Fuel Cutoff switches and operate in the same sense (i.e. down for Cutoff). They are guarded and never normally moved but, with an intent to move the stab switches, \x93muscle memory\x94 (cerebellum activation if you prefer) may have taken the Captain\x92s hand to the Fuel switches, which are operated on every flight. The FO (who is PF) is manually flying at this stage sees and queries it. The Capt denies it, as he doesn\x92t realise what he has done (confirmation bias perhaps). After a few seconds, the terrible mistake is realised, and the fuel switches are moved back to run, but sadly too late and the Capt makes a Mayday call.
Perhaps a bit of a stretch but not as much of a stretch as many of the other scenarios in this thread. I think it is a real possibility. Sadly, the only other explanation that I can see is the deliberate \x93bad faith\x94 scenario, which we would all hope is incorrect.
Fly Safe
PJ88
For consideration, here is a possible scenario that hasn\x92t been mentioned yet and encompasses the frailty of human performance. The report mentions that the flight crew on the immediately prior flight had written up a "STAB POS XDCR" status message, and that troubleshooting was carried out. I wonder if the scenario could be that the accident crew received a Stabiliser EICAS message on or around take-off and the Capt (who was PM) decided to action the first checklist item immediately from memory, by intending to move the Stab switches to Cutoff but moving the fuel switches instead. As in all modern Boeings, the Stabiliser Cutoff switches are immediately next to the Fuel Cutoff switches and operate in the same sense (i.e. down for Cutoff). They are guarded and never normally moved but, with an intent to move the stab switches, \x93muscle memory\x94 (cerebellum activation if you prefer) may have taken the Captain\x92s hand to the Fuel switches, which are operated on every flight. The FO (who is PF) is manually flying at this stage sees and queries it. The Capt denies it, as he doesn\x92t realise what he has done (confirmation bias perhaps). After a few seconds, the terrible mistake is realised, and the fuel switches are moved back to run, but sadly too late and the Capt makes a Mayday call.
Perhaps a bit of a stretch but not as much of a stretch as many of the other scenarios in this thread. I think it is a real possibility. Sadly, the only other explanation that I can see is the deliberate \x93bad faith\x94 scenario, which we would all hope is incorrect.
Fly Safe
PJ88
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 13, 2025, 07:18:00 GMT
permalink Post: 11921078
The Action Slip scenario
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 flips 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 l oses 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?
Edit: I got the roles mixed up; in a fixed scenario, either the Captain was the PF (and may have set the switches to cutoff), or flight control changed over at the power failure.
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 flips 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
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?
Edit: I got the roles mixed up; in a fixed scenario, either the Captain was the PF (and may have set the switches to cutoff), or flight control changed over at the power failure.
Last edited by Musician; 13th July 2025 at 08:03 .
July 13, 2025, 07:36:00 GMT
permalink Post: 11921087
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.
\x97\x97\x97
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.
\x97\x97\x97
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\x97aviate!\x97and 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.
\x97\x97\x97
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.
\x97\x97\x97
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\x97aviate!\x97and 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?
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 14, 2025, 00:26:00 GMT
permalink Post: 11921800
Did Captain cut fuel, get challenged by FO, and then fuel turned back on too late?
Or did Captain cut fuel, accuse FO to get it on the record, and then fuel turned back on too late?
If FO cut fuel, would expect a more assertive comment and faster intervention.
Or did Captain cut fuel, accuse FO to get it on the record, and then fuel turned back on too late?
If FO cut fuel, would expect a more assertive comment and faster intervention.
For me the prelim report just reveals an unintended consequence of relying on muscle memory to carry out an action that has been performed multiple times without confirmation. It happens a lot but rarely with such a tragic consequence. I have turned the ignition switch to Normal during an engine start when asked to set the park brake during a pushback. There have been multiple occasions where an A320 park brake was set when a flap setting was commanded. On more than one occasion the flaps have been raised when "gear up" was commanded. This may not have been the first time the FCO switches have been selected but definitely the first time it wasn't picked up early enough to reverse the action.
As to the CVR recordings, I will repeat what I have often stated previously. There is no inherent right of the public to receive a full transcript of the CVR in order for them to form their own opinion of what happened. It is up to the Indian AAIB to conduct an investigation under the requirements of Annex 13 and possibly a fuller transcript of the CVR will be published in the Final Report to help the reader gain an understanding of what happened.
My belief is that CVideoRs, with robust protections and legislation around their use, will help accident investigations immensely by answering some of the what questions that the FDR and CVR don't seem able to. It doesn't have to be set up like the many Go-Pro images that are on social media. All that is needed is an image of the center console and the engine display and EICAS/ECAM screens .There would be no need to have images of the pilots faces.
July 14, 2025, 08:51:00 GMT
permalink Post: 11921972
July 14, 2025, 09:01:00 GMT
permalink Post: 11921978
It will also increase T&C, given the sudden need for an extra thousands pilots.
Then I guess once recognized as fatigued by AI we can consider ourself unfit to continue safe operations. The other one can declare a mayday and land at nearest suitable as he's in single pilot ops. I wonder what happens when he also gets identified as fatigued, do we park the plane and get some sleep?
With 14 hours legal duties and 18 hours of legal awake time...as said...that'd be a blast!
July 14, 2025, 09:03:00 GMT
permalink Post: 11921980
Newspaper Reporting
Last edited by Europa01; 14th July 2025 at 10:57 . Reason: Removal of colloquial term
July 14, 2025, 09:53:00 GMT
permalink Post: 11922013
July 14, 2025, 09:58:00 GMT
permalink Post: 11922018
The former seems very discredited.
Last edited by Someone Somewhere; 14th July 2025 at 10:17 .
July 14, 2025, 10:18:00 GMT
permalink Post: 11922040
If you want to imply poor Moderation then it would help your case to get your facts straight before claiming such articles as being “confirmatory sources” 🤔 🙈
July 15, 2025, 16:59:00 GMT
permalink Post: 11923087
Having read through most of the posts in this and the other threads, and the preliminary report a few times in parts, am mystified by this:
The Preliminary Report states: "The CCTV footage obtained from the airport showed Ram Air Turbine (RAT) getting deployed during the initial climb immediately after lift-off (fig. 15). No significant bird activity is observed in the vicinity of the flight path. The aircraft started to lose altitude before crossing the airport perimeter wall."
Does this mean the RAT deployed "immediately after" in the sense of within 1 second after lift-off?
We, as a group, certainly seem to be interpreting the "immediately thereafter" in a prior paragraph to mean that the E1 and E2 fuel cutoff switches went RUN -> CUTOFF within 1 second or so after max airspeed of 180kts at 08:08:42.
The prior paragraph for quick ref:
"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."
Additionally, have to say, this PR has a few major weaknesses in it:
- no timestamp for RAT deployment, though RAT hydraulic power coming online has one; also is it for initial power or rated power?
- no timestamp for the pilot conversation about 'cutoff', though it is provided for the MAYDAY.
- no timestamps for E1/E2 Fuel Cutoff Switches going from RUN -> CUTOFF, though they're provided for CUTOFF -> RUN.
The Preliminary Report states: "The CCTV footage obtained from the airport showed Ram Air Turbine (RAT) getting deployed during the initial climb immediately after lift-off (fig. 15). No significant bird activity is observed in the vicinity of the flight path. The aircraft started to lose altitude before crossing the airport perimeter wall."
Does this mean the RAT deployed "immediately after" in the sense of within 1 second after lift-off?
We, as a group, certainly seem to be interpreting the "immediately thereafter" in a prior paragraph to mean that the E1 and E2 fuel cutoff switches went RUN -> CUTOFF within 1 second or so after max airspeed of 180kts at 08:08:42.
The prior paragraph for quick ref:
"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."
Additionally, have to say, this PR has a few major weaknesses in it:
- no timestamp for RAT deployment, though RAT hydraulic power coming online has one; also is it for initial power or rated power?
- no timestamp for the pilot conversation about 'cutoff', though it is provided for the MAYDAY.
- no timestamps for E1/E2 Fuel Cutoff Switches going from RUN -> CUTOFF, though they're provided for CUTOFF -> RUN.
Last edited by T28B; 15th July 2025 at 17:15 . Reason: formatting errors fixed.
July 17, 2025, 00:44:00 GMT
permalink Post: 11924076
If the final report, transcript and all, is released 2 years from now, there will be little media interest. Today's media works on today and tomorrow, not the long past. Even if the tragedy was caused by a deliberate action of a pilot, it will garner little publicity. Good for the manufacturers, good for the regulatory authorities and good for the airline concerned. All will be quietly swept under the carpet, thanks to time elapsed.
But the findings could be a heartbreak for many families. To say nothing of the departed souls in the aircraft and on the ground. And the injured.
...
But the findings could be a heartbreak for many families. To say nothing of the departed souls in the aircraft and on the ground. And the injured.
...
The cockpit recorder almost certainly enables the investigators to distinguish between the voices recorded and identify which of those voices belongs to the PIC and which to the FO. And, based on my reading of previous posts, the cockpit recorder may have even picked up the 'clicks' of the fuel control switches. And the investigators almost certainly know which of the PIC and FO transmitted the MAYDAY. That all resolves to a small number of likely scenarios, which scenarios have been described (repeatedly) in this thread, all of which should already have been formulated by the investigators.
For the life of me, I cannot see the point of the investigators not coming out and saying: "At this point, we are confident of at least these facts: ... Unfortunately, it follows that we are confident that either the PIC or FO switched off both fuel control switches seconds after take off. That all leads us to be confident that one of X combinations of actions occurred in the cockpit, but we have yet to have any confidence as to what motivated any one or more of those actions: ..."
Look at how many NTSB update briefings occurred in the wake of the mid-air collision involving the CRJ and Blackhawk at DCA. The ATC recording is publicly available. What damage was done, to whom, by those update briefings or the publication of the ATC recording?
July 17, 2025, 02:18:00 GMT
permalink Post: 11924094
I think it's simply inhumane to put the thousands of family members and friends of those who died in this tragedy through the stress caused by the protracted uncertainty as to who did what, and why, in the cockpit. And my view is that the scope for ongoing speculation does no favours for the interests of pilots or aviation safety.
The cockpit recorder almost certainly enables the investigators to distinguish between the voices recorded and identify which of those voices belongs to the PIC and which to the FO. And, based on my reading of previous posts, the cockpit recorder may have even picked up the 'clicks' of the fuel control switches. And the investigators almost certainly know which of the PIC and FO transmitted the MAYDAY. That all resolves to a small number of likely scenarios, which scenarios have been described (repeatedly) in this thread, all of which should already have been formulated by the investigators.
For the life of me, I cannot see the point of the investigators not coming out and saying: "At this point, we are confident of at least these facts: ... Unfortunately, it follows that we are confident that either the PIC or FO switched off both fuel control switches seconds after take off. That all leads us to be confident that one of X combinations of actions occurred in the cockpit, but we have yet to have any confidence as to what motivated any one or more of those actions: ..."
Look at how many NTSB update briefings occurred in the wake of the mid-air collision involving the CRJ and Blackhawk at DCA. The ATC recording is publicly available. What damage was done, to whom, by those update briefings or the publication of the ATC recording?
The cockpit recorder almost certainly enables the investigators to distinguish between the voices recorded and identify which of those voices belongs to the PIC and which to the FO. And, based on my reading of previous posts, the cockpit recorder may have even picked up the 'clicks' of the fuel control switches. And the investigators almost certainly know which of the PIC and FO transmitted the MAYDAY. That all resolves to a small number of likely scenarios, which scenarios have been described (repeatedly) in this thread, all of which should already have been formulated by the investigators.
For the life of me, I cannot see the point of the investigators not coming out and saying: "At this point, we are confident of at least these facts: ... Unfortunately, it follows that we are confident that either the PIC or FO switched off both fuel control switches seconds after take off. That all leads us to be confident that one of X combinations of actions occurred in the cockpit, but we have yet to have any confidence as to what motivated any one or more of those actions: ..."
Look at how many NTSB update briefings occurred in the wake of the mid-air collision involving the CRJ and Blackhawk at DCA. The ATC recording is publicly available. What damage was done, to whom, by those update briefings or the publication of the ATC recording?
First, the DCA collision occurred against the backdrop of significant weaknesses in the United States ATC system. The accident itself may have involved acts or omissions by the Army helicopter pilot or pilots, so there is that similarity in a general sense. But although a non-aviator, I did understand the many statements on the threads and in the general media about the difficulty of "visual separation" at night, particularly in the D.C. area and in the approach corridors to DCA. This is quite unlike the surpirse and/or disbelief that an experienced airline aviator would move fuel control switches to cutout at or nearly at the time of rotation. So the nature of the acts or omissions in question is quite different.
Second, it obviously occurred at Washington, D.C.'s close-in airport, which has been such a focal point of Congressional "air commuters".
There also is a difference in the likely litigation courses the two accidents will follow. On the premise that the WSJ report aligns with what appears to be the consensus on this thread - namely that the PM moved the switches although no one now knows why - and then reasoning further from that premise, the litigation to be faced by Air India will be considerable. I do not know the Law of India whatsoever, but under the Montreal Convention system for liability determinations and damages, I think it is a very easy straightforward assessment to say that the airline is going to face intense litigation challenges. In that light, the families will have their day in court (I mean, even without knowing Law of India, I think that's safe to say). Going beyond what - if I am reading and understanding the posters with actual significant investigation experience correctly - is the formal or nominal charge of the AAIB in this matter is not required in order to help the families. (And how bad would it be for them if the AAIB had to retract or materially change some information released ahead of determinations with certainty?)
Not least, in the DCA accident the legal landscape is quite diffrerent. Without rehashing the (perhaps tedious) posts I put on the DCA thread, the scope of available legal relief is quite limited under applicable federal law (just for reference, the "discretionary function exception" to the allowance to sue federal entities will almost certainly limit the scope of recoveries available from the Army or FAA/Dept of Transportation; the airline can be sued but it will be, in my not-so-hmo, ridiculous and mercenary to do so, as the CRJ and its tragically ill-fated crew had done nothing wrong).
Somewhat relatedly, on the WSJ article, while its sources are unnamed, I'm trying to recall a single article published in that newspaper (including online) about a major aviation incident which later was shown to have been inaccurate. Maybe there are one or more examples. Generally The Air Current's publisher got a very good start.
July 17, 2025, 06:08:00 GMT
permalink Post: 11924148
I think it's simply inhumane to put the thousands of family members and friends of those who died in this tragedy through the stress caused by the protracted uncertainty as to who did what, and why, in the cockpit. And my view is that the scope for ongoing speculation does no favours for the interests of pilots or aviation safety.
The cockpit recorder almost certainly enables the investigators to distinguish between the voices recorded and identify which of those voices belongs to the PIC and which to the FO. And, based on my reading of previous posts, the cockpit recorder may have even picked up the 'clicks' of the fuel control switches. And the investigators almost certainly know which of the PIC and FO transmitted the MAYDAY. That all resolves to a small number of likely scenarios, which scenarios have been described (repeatedly) in this thread, all of which should already have been formulated by the investigators.
For the life of me, I cannot see the point of the investigators not coming out and saying: "At this point, we are confident of at least these facts: ... Unfortunately, it follows that we are confident that either the PIC or FO switched off both fuel control switches seconds after take off. That all leads us to be confident that one of X combinations of actions occurred in the cockpit, but we have yet to have any confidence as to what motivated any one or more of those actions: ..."
Look at how many NTSB update briefings occurred in the wake of the mid-air collision involving the CRJ and Blackhawk at DCA. The ATC recording is publicly available. What damage was done, to whom, by those update briefings or the publication of the ATC recording?
The cockpit recorder almost certainly enables the investigators to distinguish between the voices recorded and identify which of those voices belongs to the PIC and which to the FO. And, based on my reading of previous posts, the cockpit recorder may have even picked up the 'clicks' of the fuel control switches. And the investigators almost certainly know which of the PIC and FO transmitted the MAYDAY. That all resolves to a small number of likely scenarios, which scenarios have been described (repeatedly) in this thread, all of which should already have been formulated by the investigators.
For the life of me, I cannot see the point of the investigators not coming out and saying: "At this point, we are confident of at least these facts: ... Unfortunately, it follows that we are confident that either the PIC or FO switched off both fuel control switches seconds after take off. That all leads us to be confident that one of X combinations of actions occurred in the cockpit, but we have yet to have any confidence as to what motivated any one or more of those actions: ..."
Look at how many NTSB update briefings occurred in the wake of the mid-air collision involving the CRJ and Blackhawk at DCA. The ATC recording is publicly available. What damage was done, to whom, by those update briefings or the publication of the ATC recording?
You can bring your objections to the attention of ICAO and lobby them to change the rules, but given these rules have been in place for decades - and have generally worked quite will - I doubt there going to change them just to satisfy your curiosity.