Air India B787 crash Ahmedabad

[Quickstatus]

AAIB AI171 Preliminary Report

FAA SAIB NM-18-33

Importantly no Emergency Airworthiness Directives

 

[jb747]

Thanks . Thats what I meant. When restarting an engine, does performing a fuel cutoff then back to Run improve the probability of relighting the engine?

Yes. I particular it moves the inlet guide vanes to a position that may make a start more likely. Ignition will be reactivated automatically.

At Vr, hands are off the power levers as part of the human factor related procedure - whatever happens after Vr, the pilots have to fly the aircraft first. Is there any reason for any hands to be anywhere the centre control panel/power/flaps in the immediate period after Vr?

Not really. People don’t wave their hands around for pretty obvious reasons. I used to sit my hands on my legs, when supporting. When flying, I generally kept only one hand on the controls, with other on leg. But, I did put it back on the thrust levers any time I expected any automatic movement of the levers. This is after takeoff only. At other times I treated the throttles like armrests….but if they moved, and I wasn’t expecting it, it was another cue. Funnily enough, I kept the same behaviour in the AB, even though the levers never move by themselves.

Found a copy of the report I could actually read. The flight prior had a message about stabilizer trim (STAB POS XCDR) which was apparently looked at and released by engineers. Any chance they received some kind of critical stabilizer trim alarm which triggered a memory item to cut out the stabilizer trim, but a brain fart meant they went for the wrong switches?

Not really. If you can fly the aircraft, then you do absolutely nothing, until you get to somewhere between 400’ and 1,000’ (depending on type and airline). Almost nothing, requires immediate attention. Of course a dual engine failure is an exception to that. On the other hand, a fire isn't’.

I was really curious about, which was the previous type ratings held by the flight crew. Of the various types and doing some Google search. Now, this is probably a total waste of time to think about, but the similarity between the engine cutoff switches in a B787 and the cowl flaps on a PA-34 struck me.

Can’t see it. Most pilots dump that sort of aircraft instantly upon getting an airline job.

You glance down and the switches are in cutoff. Based on the audio one pilot assumed the other did it. That was his immediate assumption. If this happened and the other pilot didn't wish others to know they had done it and knowing it was recorded they would have the response they did.

If they were in cutoff, and you didn’t do it yourself, then you’d assume the only other person there did it. Natural enough. I doubt that anyone who had 30 seconds to live, and might go in an unpleasant way, would be all that capable of worrying about the voice recorder contents.

You'd think that have a camera in the coughpit recording to the block box recorder would be something they would do these days.

I’m generally anti cameras, but this event might change my mind.

If the switches are not guarded, ie sitting up, do you get an alert on the screen?

For example, did someone leave the fuel unguarded, then, as takeoff occurred simply quietly push them back? Would explain the 1 second timeframe both got moved from to the off position.

You don’t get message about the switch position, only the outcome. Assuming they were the normal switches, not the ones without the lock, I can’t see that you could leave them “unguarded”. It isn’t that sort of guard. Having said that, it’s not impossible.

 

[Must...Fly!]

Can’t see it. Most pilots dump that sort of aircraft instantly upon getting an airline job.

Good to know!

Thanks as always for the detailed post in reply to many queries.

Post automatically merged: Today at 12:11 AM

Are you able to provide a link to the copy of the report that you found?

There is a link to a copy hosted by this media outlet: Air India flight AI171 crash: Read the full report by AAIB

 

[RSD]

There is a link to a copy hosted by this media outlet: Air India flight AI171 crash: Read the full report by AAIB

I've just had a read of the report.

It seems from the report that any movement of the fuel control switches is recorded by the flight data recorder.

The fuel control switches were turned to off three and four seconds respectively after the aircraft took off - and well before it had cleared the airport boundary fence - why is the big question now. Or - is the information that has led to the FDR being informed that the fuel control switches have been turned to the off position taken from somewhere other than the switches themselves? I.E. is the FDR "sensing" that the switches are off because it is not receiving a power signal at a different point in the wiring circuit downstream of the switches? (and that location is being used to detect/monitor the switches - I.E. if we have power at location Y then that is indicating that the actual switches at location X are in the run mode - rather than something actually monitoring the actual position of the switches themselves).

 

[DC3]

… why is the big question now …

 

[Happy Trails]

Said switches (lifted from FB, unverified).

 

[RSD]

Said switches (lifted from FB, unverified).
View attachment 457442

This is a screen grab taken from Blancolirio's youtube video that he posted today - which suggests that your photo is of the same switches -

 

[jb747]

Given that we now know that the aircraft was being flown by the FO, it seems likely that the phantom switch flicker is the captain. The conversation then makes sense. The gear lever is still down, so it also seems that the gear was never selected up. It looks like the switches were moved at the point where the gear would normally have been selected. You’d have to presume it’s intentional, or the worst brain fart in history.

 

[Grrr]

8:8:42 both switches to cut-of within a second
Question asked why that was done - denied
RAT deployed

So the RAT will be deployed if you manually cut the fuel but everything else is working normally ?

 

[jb747]

So the RAT will be deployed if you manually cut the fuel but everything else is working normally ?

I would assume that the air/ground logic comes into play here.

 

[Saab34]

Given that we now know that the aircraft was being flown by the FO

Where was this mentioned?

 

[markis10]

Where was this mentioned?

In the report.

 

[Saab34]

Interesting. Going to need to dive into the Captain’s life now. Was he demoted? Not happy with the new direction of AI? Obviously a lot of change at AI and he appears to be one of the older legacy employees from the prior era, with management running it now from the west, I’d imagine that will upset some of the legacy employees, often the case in these sort of cultures.

 

[SYD]

Interesting. Going to need to dive into the Captain’s life now. Was he demoted? Not happy with the new direction of AI? Obviously a lot of change at AI and he appears to be one of the older legacy employees from the prior era, with management running it now from the west, I’d imagine that will upset some of the legacy employees, often the case in these sort of cultures.

Apparently a few months away from retirement.

The FO was soon to be married.

Who were the pilots of ill-fated AI Ahmedabad-London flight

Captain Sumeet Sabharwal, First Officer Clive Kunder, both from Mumbai, were declared fit for duty

indianexpress.com