Posts by user "CharlieMike" [Posts: 16 Total up-votes: 0 Pages: 1]

Originally Posted by OPENDOOR

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.

Originally Posted by kristofera

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.

Originally Posted by Icarus2001

I looked for a B787 EFATO memory item in the QRH but could not find one. Perhaps a current B787 pilot could confirm?

Originally Posted by Icarus2001

I am only asking about an engine failure memory item. Fire, separation or severe damage being a different beast.

Are you confirming that there is no specific engine failure memory item? When safe run the QRH?

Originally Posted by Musician

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?

Originally Posted by B2N2

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

Originally Posted by ManaAdaSystem

A lot of \xabflipping\xbb and \xabflicking\xbb of fuel switches going on. You don’t flick or flip these switches. They require a deliberate movement.

Originally Posted by Bunk-Rest

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.

Originally Posted by enderman

Action slip seems highly unlikely to me. Even if one cutoff switch was moved in response to a gear up request I can\x92t believe anyone would then move a second switch, one second later.

Originally Posted by Bunk-Rest

Why did you do cutoff ? Question may have been directed at the third person in the cockpit who had actually done it.

Originally Posted by ManaAdaSystem

Yes, and on the 737 and 320, there is a dedicated switch to turn it on before engine start when it starts automatically. I\x92m sure the 787 is similar.

Originally Posted by adfad

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. Switches moved deliberately - evidenced by the specific question "why did you cutoff" and circumstanced by this being the most vulnerable phase of flight to do such a thing
2. Switches moved accidentally eg., 'action-slip' - is there a precedent for not 1 but both switches of this type in any similar aircraft being cut off during routine operations?
3. Switches failed mechanically or electronically - the recovered switches were in the position consistent with flight data, timing data is consistent with manual 1-by-1 movement

Originally Posted by adfad

(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.

Originally Posted by sabenaboy

I'm sincerely hoping that this reply will not be deleted.

Originally Posted by MissChief

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.