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CharlieMike
June 12, 2025, 12:04:00 GMT permalink Post: 11899133 |
Daily Mail have already been quoting this thread about the RAT.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) |
CharlieMike
June 14, 2025, 16:21:00 GMT permalink Post: 11901619 |
During the nearly two years that elapsed between AF 447 disappearing and the recovery of the flight data recorders nobody suggested that the PF might have, unwittingly, flown the aircraft, stalled, into the ocean.
AI 171 may prove to also have a totally unpredicted cause. I\x92m absolutely not speculating this is the case here, but could you not achieve the effect this flight suffered by just switching off the fuel control switches at 100ft on takeoff? There are now so many assumptions based on the assumed state of flap, RAT etc that it\x92s becoming pointless speculation. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Switches RAT (All) |
CharlieMike
June 14, 2025, 20:32:00 GMT permalink Post: 11901805 |
Just a thought regarding the possibility of some kind of sensor failure: mud wasps.
Since this was a short stopover, perhaps pitot covers were not used. Mud wasps can build their nests in a very short timespan, and they have been known to block pitot tubes and static pitot ports in the past. Just throwing this out there as one additional possible hole in one of the slices of cheese. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): EICAS |
CharlieMike
June 21, 2025, 08:23:00 GMT permalink Post: 11907570 |
EFATO handling is similar on most types too\x85in essence, contain any yaw, rotate, get the gear up and either trim it out or (787) let the aircraft trim it out\x85.AP in and once safely climbing away at a defined altitude diagnose followed by memory items if applicable. 787 you don\x92t action any drills until above 400ft so it would be extremely unlikely this crew actually got the stage of touching a fuel control switch. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): EFATO Engine Failure (All) Memory Items |
CharlieMike
June 21, 2025, 08:43:00 GMT permalink Post: 11907580 |
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Engine Failure (All) Memory Items |
CharlieMike
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? 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. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Action slip CVR Fuel (All) Fuel Cutoff Switches Generators/Alternators Hydraulic Failure (All) MAYDAY Preliminary Report RAT (All) RUN/CUTOFF |
CharlieMike
July 13, 2025, 07:53:00 GMT permalink Post: 11921099 |
You don’t “flick switches in the Sim” for no apparent reason.
Even Indian sources are now reporting on the possibility of intent. https://www.ndtv.com/india-news/air-...-probe-8864239 Intent is a possibility but I’m leaning away from it because of the other factors…gear remained down at positive rate, the ensuing conversation and an apparent attempt to immediately rectify the situation. Much like Germanwings, I’d say a suicidal pilot would remain quiet and uncooperative once they’ve taken the unthinkable decision. Subjects: None |
CharlieMike
July 13, 2025, 08:08:00 GMT permalink Post: 11921110 |
A statement that completely underestimates the human subconscious system. You need a deliberate movement to raise the gear or drop the flaps too…I’d say nearly every operator has instances of pilots accidentally doing one instead of the other. There will be people saying that there is no way you can have such an extreme action slip but I don’t think we should ever underestimate the power of the human to do the most random things, even if it is one-in-a-million event.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Action slip Fuel (All) Fuel Cutoff Switches |
CharlieMike
July 13, 2025, 08:19:00 GMT permalink Post: 11921120 |
Whoa\x85
Suppose there was a third person on the flight deck ? Unauthorised possibly, knowing air india\x85. And he did it. He is out of the pilots field of view, he can reach them easily with both hands, and absolutely explains the verbal exchange that took place. When does the voice recorder start running? Engine start if I remember vaguely. So the presence of a third person may be totally undetected in the recordings. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Jump Seat |
CharlieMike
July 13, 2025, 08:21:00 GMT permalink Post: 11921123 |
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Action slip Fuel (All) Fuel Cutoff Switches |
CharlieMike
July 13, 2025, 08:43:00 GMT permalink Post: 11921144 |
The switches were operated at 3s after liftoff\x85exactly the time positive rate would be confirmed\x85so I\x92m still thinking third party isn\x92t the most likely scenario. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR Fuel (All) Fuel Cutoff Switches Jump Seat Pilot "Why did you cut off" |
CharlieMike
July 13, 2025, 09:01:00 GMT permalink Post: 11921158 |
Don\x92t think there is. I can only think of CVR test and erase switches on the OHP. The FCOM is also vague and says \x93continuous recording\x94, so it may be from CCS power-up.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR FCOM |
CharlieMike
July 13, 2025, 09:15:00 GMT permalink Post: 11921169 |
I don't see any evidence here. The report doesn't mention any callout of positive rate or request for gear up. The cutoff switches were moved ~3 seconds after wheels leaving the ground which would have been just before or at roughly the same time as the callout. The report did not say "pilot flying requested gear up and then the switches were moved to cutoff". There is also no evidence of a 3rd person and I'm not even sure how that would make a difference.
I see 3 meaningful explanations roughly by order of probability
(1) It\x92s still a likely response to ask that question if your colleague had just switched them off by action-slip. (2) See my post above. Routine use of these switches is in one \x93event\x94\x85below OAT 40C you start both simultaneously and at shutdown you operate one straight after another. (3) The interim report seems to leave out all information on verbal exchanges not specifically involved with a response to the abnormal situation. Not saying you aren\x92t correct, but it doesn\x92t change the order of likelihood in my mind. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Switches Pilot "Why did you cut off" |
CharlieMike
July 13, 2025, 11:28:00 GMT permalink Post: 11921248 |
(1) is true I give you that, but there is no followup "I didn't.. oh crap", denial is a reasonable response if you truly haven't registered doing something, but it is also a reasonable response if you want to confuse to delay
By precedent in routine operations I mean: is there a single example of these switches being cut off at takeoff like this? There is precedent for the wrong engine being shut down in a fire sure, and there is perhaps precedent for mishaps with the fuel switches in other cockpit layouts - but in the case of this layout, with this model of switch or even this 'style' of switch and placement, I cannot find a single example that would come close to the level of catastrophic action slip of pulling out and setting to cutoff both switches one by one. I think the preliminary report is supposed to present all factual information - they could have left out "why did you cutoff / I did not" - I could understand if they left out sounds that could be ambiguous, perhaps indicating a struggle but not clear enough to present as fact. However, "positive rate / gear up" followed by 2 switches instead of gear handle is completely factual and relevant information, to exclude it makes no sense. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Action slip Engine Failure (All) Fuel (All) Fuel Cutoff Switches Pilot "Why did you cut off" Preliminary Report |
CharlieMike
July 13, 2025, 12:24:00 GMT permalink Post: 11921284 |
And I think they are quite right to delete your post, and should also delete the latest one. Whilst many of us have pilot suicide as an option amongst other scenarios, you seem to be hell bent on pushing this as the de facto cause…look at your bold text and the language of your last post. It may be a possible cause, but there are other scenarios that are not unlikely at this stage. You seem to want to jump to lay blame before the scenarios that don’t have a pilot being an intentional killer are ruled out…it’s extremely distasteful.
Subjects: None |
CharlieMike
July 13, 2025, 13:28:00 GMT permalink Post: 11921324 |
I agree with sabenaboy.
The subject of pilot suicide is not distasteful, but for many it is taboo. I understand this. Many historical accidents caused by pilot incompetence could well have been quickly labelled as suicide, only for their errors to show up in the subsequent investigation. Looking for a rational explanation is a normal way to go, and suicide is not rational in most peoples' eyes. However, this tragic event looks highly probable to have been caused by a deliberate action. And shutting off the fuel controls immediately following rotation is impossible to justify as an accidental move. I remember calling the German Wings accident as a likely suicide event as soon as I heard about it. Nevertheless I was open to hostility and recriminations on this website for quite a few days, once my carefully-worded contribution was not deleted. I do wonder if any further information can be gleaned from the FDR, which has not already been shared. I hope so. And of course, the CVR contents require further analysis. Nobody in their right minds takes any pleasure, woke or not, from learning of a suicide, particularly one that involves the death of many innocent people. There is always some virtue signalling poster on all these threads saying “we shouldn’t speculate until the full report comes out”…I’m not one of those, but I’m happy to call out someone pointing the finger when the available evidence still very inconclusive. I hope the mods frustrate him further by deleting his efforts. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR FDR Thread Moderation |
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