Posts about: "Fuel (All)" [Posts: 1005 Pages: 51]

You are desperately trying to make the scenario fit . Things aren\x92t left on the FCS . I\x92ve tried knocking em off in the sim doesn\x92t work .

Have you ever moved a set of them ? I\x92ve been moving them for 23 years on Boeings from 757 to 787. If they were really set to cutoff at the end of the runway it\x92s deliberate .. BUT we need more info \x85


FO was flying \x85 Capt moves them and then says \x93 why did you .. etc \x93 , Poor FO doing his best to stay in the air

Yes can we just accept this as a fact because the bizarre scenarios some folks are coming up with are just damn ludicrous and frankly destroy the purpose of pprune.

If you\x92ve ever moved those switches you know how they work and you know it\x92s impossible for anything to knock them or move them out of the detent.

Over the years there have been many \x93slips\x94 that have led to accidents, I\x92m yet to come across one which involved both FCS inadvertently being cutoff. The design works, believe it or not.

These for me are very interesting questions.

There seems to be a period around second 12/13 post V1 where engines are (or should) be likely below idle, but prior to RAT power generation.

Note that the report explicitly states the RAT started providing hydraulic power 5 seconds after engine shutdown commenced. It doesn't reference electrical power. So we don't know whether this was at the same time - others may clarify re: RAT operation.

But either way, it would appear there would be a gap in power (which, incidentally, would tie in with the survivor commentary). But yet ADS data continued.

If in fact there was a momentary loss of power then that would contribute heavily to the startle and "delay" in refiring (although comments here make me think there wasn't really such a delay anyway).

(And incidentally would make what appears to be a really rather valiant attempt to save the aircraft even more impressive)

To be honest this is the best argument against suicide I have seen here - but human psychology can appear illogical and half-hearted. I can't imagine it is easy to go through with such a thing and must take every ounce to force it, with self questioning and doubt throughout. Also I was under the impression that pushing a fire handle back in would allow an engine to be restarted if the fuel switch was set / cycled to run - can anyone confirm or deny?

The evidence shows 2-3 extraordinary possibilities all full of caveats, and since nothing else has been issued it seems incredibly unlikely that anyone involved in the investigation is concerned that there is a chance of accidental cutoff from the switch, electronics, software or cockpit design.

Former Boeing Engineer on the 787 (prob should put this in my profile at some point but newbie on the forum), but personally flown nothing bigger than a 172.

Longer I think about this the more I lean towards purposeful but not intentional action slip cutoffs by the captain. Some people have commented on sim training captains doing this to reset quicker (i wouldn't know).

We know FO was flying and initial cut offs are 1 then 2, which to me says CAPT did it. But also relights were 1 then 2 which tells me CAPT also did that one most likely.

Also comments around 10 seconds of delay being a long time, that's REALLY fast in my opinion especially considering, 1. this is a situation that is never trained for and 2. All sorts of lights changing, displays flickering, whole right side of the cockpit basically turning off and 3. Your really close to the ground and transitions (from takeoff to climb) lend themselves hard things to break your mind out of. That has to be a very jarring experience that needs likely a few seconds just to re-orient themselves. I'm honestly impressed they got them re-lit that fast, but assuming training with engine out and re-start procedures likely gave them a hint fuel switches from the EICAS messages.

Very confident Boeing FlightOps engineers and training captains have run through this in the sim quite a few times now.

I've been following this with interest from the start. My very first reaction when I saw it was that it was a double-engine failure, clearly I was intrigued to know whether it was pilot or system initiated.
I don't think from what we've told that you can draw a conclusion either way. The data shows that the FDR recorded both fuel switches being off, then back to on. The crucial piece here is that it's only a signal from the system, not a physical check of switch position, that provides the signal.
It's entirely possible that the physical switches were not moved. The CVR recording of the other pilot stating that he didn't move them is fascinating in this context.

Indeed.

Wasn\x92t the same said about the Capt of MH370? Darkness hides deep within the shadows.

It certainly is very puzzling though.

Could it be that the one who cut off the fuel control switches was the one who said \x93why did you cut off the fuel switches\x94, hence the reply \x93I didn\x92t\x94 as the other guy didn\x92t actually do it?

Could that be an attempt to manipulate the CVR?

Is there? Is there evidence for the scenario that you have endorsed, that the Captain deliberately, intending to crash the airplane, moved the fuel control switches to CUTOFF and then accused the FO of doing that? What is that evidence?

Some human in that flight deck moved both fuel switches to cutoff, physically moved them, one after the other. Another human, possibly either human in that flight deck then questioned verbally why they did that. This is factual and proven evidence as per the official report. Why are we not focusing on the who and why!?

Not sure how much more evidence you need to start a discussion.

We as operators are trying to put ourselves in that situation and describe likely outcomes based on present experiences. The most likely event is the PM orchestrating this, the Captain in this case. This however is up for debate\x85 the debate we should be having\x85 not APU doors.

Because it wouldnt have been immediately available to support engine restart and/or other electrical functions, as it didn't open until around 13 seconds after cutoff event. It's relevant in so much of how it may (or may not) have affected recovery efforts.

It was working as per the conditions absolutely, but those conditions meant it wasn't available immediately.

I hardly think that the single sole relevant learning from an event such as this, and hence the sole discussion point, is around the trigger of the event. Yes, very relevant, but plenty of other areas to understand further as well (for example how a dual engine failure at such altitude could be adjusted in future process). If you aren't interested in that discussion that's ok of course, but it doesn't make it irrelevant.

A recovery of AC electrical power isn\x92t necessary for the FDR to record its findings as it\x92s powered by the hot battery bus.

I don't remember joining a debate about the APU door. In fact, I haven't seen such a debate, although I have seen some questions and speculation. I didn't read those posts carefully, but I got the sense that they were in the context of speculation about the possibilities for engine restart and thrust recovery, not about possible causal factors. Maybe I got that wrong.

I certainly don't need more evidence than we have for discussion. I just think a lot more evidence is necessary to conclude that either crew member on that flight deliberately killed the engines intending to crash the jet and, for some reason, accused the other of doing so. Indeed, I don't think we have any actual evidence for that. We simply have a set of circumstances that make that one of only a few possibilities we can reasonably imagine. Discussing it as a possibility is reasonable (although I don't think we can get anywhere on that path without evidence), but claiming that possibility as the one, the truth, what really happened, is not reasonable, not justified by the available evidence. And making unjustified claims that amount to accusing a pilot of mass murder, in a forum that citizens and journalists from around the world always turn to for information in the wake of a major airliner crash, seems like a very bad idea to me.

Quote: Originally Posted by Contact Approach
But there is evidence, pretty clear evidence!
The "evidence" might be available, but I disagree it is available to us. I assert the prelim report has been deliberately sanitised to prevent us (i.e. everybody outside the AAIB circle) being given enough 'evidence' to make certain conclusions.

You/others might not like it, some might say it is obvious (I say not), but I think it is carefully worded enough to imply what might have happened, but nothing is clear - intentionally.

Non-pilot here.

For those interested in reading more about 'action slips', including performing one routine function in place of another, the following free-access article goes into more detail:

Wiley Online Library: Oops! I Did it Again: The Psychology of Everyday Action Slips

As other people have perspicaciously pointed out, assuming that it was the Pilot Monitoring that transitioned the Fuel Cut-Off Switches from RUN to CUTOFF, what action would they likely have been attempting to perform at that stage of the flight for an action slip to be a likely possibility?

Alternatively, given that the PM was used to operating simulators, what conditions could have prompted him to do a sequence that was familiar to him of resetting the simulator (including operating the FCS switches), doing things that are inadvisable in a real aircraft?

If these are stupid questions, I apologise for taking up a mod's time processing the comment deletion.

Well, I did say that it was amazing to me.

Theyre good questions. I\x92ve only been a sim \x93victim\x94 but many sim scenarios will require resetting things back to normal. Aborted takeoff after engine failure for example or land with an engine failed and a quick start.

I\x92m inclined to give equal wait to intentional shutting down the engines (suicide, if you will) and \x93action-slip\x94. Three seconds after WOW and calling for \x93gear up\x94 is quick but not hugely so. We don\x92t have the transcript, we don\x92t know if the voices were associated with which pilots. It\x92s entirely possible, there was \x93positive rate\x94, \x93gear up\x94 exchange followed by the movement of the switches by the PM, followed by \x93why did you cut off\x94 by the PF who is soon without a PFD.

As to timing, in high stress situations, the mind can run like a computer slowing time or just the opposite, time speeds up and seconds go by trying to comprehend the situation. I was in an ejection, I could spends 15 minutes describing what happened in 500 milliseconds.

Startle will absolutely play a role, largely because no pilot is ever trained to deal with both FCS being cutoff a few seconds after rotate\x85 that would be suicide, for want of a better word.

The two fuel cutoff switches were put in the OFF position. If you have ever used those switches yourself, you will know that it can not be accidental. A deliberate action from one of the pilots is BY FAR the most plausible (or only) explanation. I feel very sorry for the innocent pilot in the cockpit and the hundreds of other victims. Having passed many medical examinations, I can assure you that psychological testing is not part of the periodic medicals.
It does appear to me that you're NOT open to evidence if you continue to deny that a deliberate pilot action is not plausible.

Please enlighten me about how much time you have spent in an airline cockpit... Judging by what you contribute I suspect it will not be much.

My own experience of simulator details was that there was always a very serious risk of adverse training occurring during the reconfiguration between the elements of a sim session.

During an actual training element pilots were of course expected to take the utmost care to brief, identify, confirm and verify every switch/lever movement and operate in the safest way possible using SOPs. But usually, just to save precious sim time, during the manual re-configuration for the next element instructors would typically rattle off a very long series of selections necessitating both pilots working flat out, hands flying around the cockpit trying to keep up.

Very easy to still be re-setting the fuel control switches while the instruction coming through the headset was \x91set the gear up\x92 (or any other combination of switches and selections). Massive risk of hardwiring in a mental slip for the future. Personally I found this to be one of the most discombobulating bits of sim details, completely destroying good \x91SOP hygiene\x92 and detaching the crew from the mental model of how the aircraft came to be in it\x92s suddenly new configuration and place in the sky.

Honestly I can think of only one occasion during my whole career where a sim instructor said, \x91Ok chaps that\x92s the first part done, hands off, flight freeze is on, now motor your seats back and listen in while we brief and the sim auto sets itself for the next bit.\x92 He then carefully spent two or three minutes building up our SA before we motored forward to get on with it. Complete revelation!