Posts by user "AfricanSkies" [Posts: 9 Total up-votes: 0 Pages: 1]

Originally Posted by nachtmusak

Regardless of what actually happened in that cockpit, reasoning like this seems completely backwards to me. Since when do humans reliably, instantly recognise that they've just made a mistake? If they were that attuned to their actions they're almost certainly attuned enough to not make the mistake in the first place, especially if we're talking about an action slip. I've e.g. absentmindedly added salt to my tea instead of sugar and I certainly didn't immediately realise that I'd done that - in fact it took a good few seconds even after sipping and spitting it out for my brain to catch up to what must have happened. Even if an observer had pointed out to me before drinking it that my tea had salt in it, I would just have been confused because obviously I wouldn't do something that silly (spoiler alert: I did)..

Originally Posted by nachtmusak

On top of that I feel like people are overestimating how long ten seconds actually is, especially considering some of those seconds are reported to have been taken up by confused dialogue (that isn't even reported in its entirety). I thought it was common wisdom that accidents are never down to one thing; it would be light-years from being the first time that suboptimal crew response turned a maybe-recoverable error into a definite disaster without an ounce of malice in the mix.

Originally Posted by Seamless

If the thrust levers were found in idle but, according to the EAFR, were set to TO thrust until the end, doesn\x92t that also raise further questions?

Originally Posted by Mb194dc

Deliberate pilot action should be ruled out until any evidence and motivation for why that's the case emerges.

All we know is the fuel cut off switches were flipped to Cutoff for 10 seconds and then to run again. Not how or by what. The focus should be on how this could occur. Accidentally, technical malfunction, a foreign object somehow hitting and moving them or other reason?

Theories needs to be tested in a cockpit with the exact configuration of this aircraft and with the angles and forces involved as much as we can. It should be possible to simulate it pretty closely and whatever happened should be repeatable. It's going to be something extremely unlikely, or we'd have seen it before in 10 years of 787 service.

Originally Posted by EXDAC

That account, which is posted as being authoritative, appears to disregard SAIB NM-18-33 which states, in part:

"In order to move the switch from one position to the other under the condition where the locking feature is engaged, it is necessary for the pilot to lift the switch up while transitioning the switch position. If the locking feature is disengaged, the switch can be moved between the two positions without lifting the switch during transition, and the switch would be exposed to the potential of inadvertent operation. Inadvertent operation of the switch could result in an unintended consequence, such as an in-flight engine shutdown.'

Since the preliminary report does not specify that this SAIB was actioned on this aircraft we do not know if it was fitted with defective switches.

In my personal opinion a defective locking feature does not explain the reported event sequence. That does not mean the switches were not defective.

Originally Posted by verticallimit

Just a thought \x97 the fire extinguisher handles perform the same function as the fuel cut-off.
Could there have been a strap /booklet or something else that accidentally got under the fire handles and activated them when one of the pilots pulled on the item?
The fire handles are not particularly well protected against something getting underneath them
Is there any information on whether the fuel cutoff switches and fire handles register as separate events on the flight data recorder, or if both are logged under a common indication, such as 'fuel switch cut off'?

Originally Posted by DTA

An answer to this is just a few posts back. Each switch has 4 sections which control different functions. It is not a single switch with software behind it. Multiple simultaneous separate failures would be needed if the switch itself did not move.

Originally Posted by Easy Street

It might be 3.01 seconds, due to the sampling rate. Still not quick, but a lot quicker than 4 seconds in the context. If it was being done by PF while trying to fly the aeroplane, then it wouldn't be as slick as the shutdown routine (and it would be against muscle memory of that routine as the switches are being moved in the opposite direction).