Air India B787 crash Ahmedabad

[jb747]

AV, have you been able to resolve the exact effect of the missing lockout that the Boeing bulletin was about. Seems to me that it removes the requirement to lift the switch, but can’t say for sure.

 

[QF029]

Poor CRM?

Or if you thought you'd flicked different switches and had made an error?

 

[AviatorInsight]

Well, if they’re wired, there’s electricity involved. They aren’t soft touch software switches that the aircraft are so full of these days, but they are not a mechanical linkage to the EECs. They’re probably very simplistic, but there’s bound to be a small circuit board associated with them. Hopefully not one board for both.

Yes, I didn’t mean that there’s a physical rod or hydraulic linkage going all the way to the engine. That’s impossible for high bypass engines anyway.

You’re right that electricity is needed. Obviously the pilot moves the switch and there’s a direct electrical path to the EEC.

What I meant saying hardwired is that it’s not routed through computers or busses. So while they are electrical they’re not software based.

It’s the selection of both from run to cutoff in under a second that seems a tad rapid. Next time you do a flight, trying timing it.

Independently yes it absolutely is rapid. I’ll definitely time it next week, unless I’m on an older NG.

My current guess is that once the hand is on the switch it’ll take between 1-1.5seconds to make the selection. I’ve noticed that when shutting down it’s a lot quicker than when going from cutoff to run. But 4 seconds to move that switch is also way too long.

AV, have you been able to resolve the exact effect of the missing lockout that the Boeing bulletin was about. Seems to me that it removes the requirement to lift the switch, but can’t say for sure.

That’s my understanding as well. It makes for a quicker relight when the switch is in cutoff. But it needs to be intentional to shut it down so you need to lift it out and down.

 

[Quickstatus]

lol

when you toggle a switch to CUTOFF,

Is there an engine mode where everything in the engine resets to a "default" position when fuel switch is cutoff?

 

[AviatorInsight]

lol

Is there an engine mode where everything in the engine resets to a "default" position when fuel switch is cutoff?

Not sure what you mean by mode. But when you move the switch to cutoff the fuel, bleed, start valves etc, all return to their “default” position.

The idea behind this is that the engine is now in a safe config to start the next cycle.

Each engine is different and from what I can find in the manuals on the 787 (albeit they’re about 8yrs old now) the FADEC resets the logic and clears any faults.

 

[Quickstatus]

But when you move the switch to cutoff the fuel, bleed, start valves etc, all return to their “default” position.

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?

....
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?

 

[Quickstatus]

And if I did see him, it wouldn’t be followed by a question.

Though the startle effect can be very strong

 

[Must...Fly!]

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?

The report also contains what I was really curious about, which was the previous type ratings held by the flight crew. Of the various types and doing some Google searches of flight deck layouts, what stood out to me was the PA-34 rating held by the F/O.

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.

https://www.alamy.com/stock-photo-boeing-787-dreamliner-coughpit-controls-30458013.html

https://www.airliners.net/photo/Untitled/Piper-PA-34-200T-Seneca-II/1062670/L?qsp=eJyrVkrOzytJrSgJqSxIVbJSKk5NLErOUNJRKkgsSswtVrKqVirOLypxqgTKlWWmljvnl%2BaVAKVBgv5FKalFQPGU1OJksI50kAnGZiYgTmpRAIRvAeKmZBYX5CRWghWXJGbmKNXWAgDocCf1

Question is, could the F/O (who was, according to the report, pilot flying) have inadvertently activated the engine cut-off by memory, while thinking they were going for the cowl flap setting from a former type? Even so, why you would touch the cowl flaps on a climb, especially in hot weather as it was on the day. Additionally, based on his CPL date I assume it has been several years since he flew such a type.

Just thought I'd throw it out there.

 

[RSD]

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?

The report also contains what I was really curious about, which was the previous type ratings held by the flight crew. Of the various types and doing some Google searches of flight deck layouts, what stood out to me was the PA-34 rating held by the F/O.

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.

https://www.alamy.com/stock-photo-boeing-787-dreamliner-coughpit-controls-30458013.html

https://www.airliners.net/photo/Untitled/Piper-PA-34-200T-Seneca-II/1062670/L?qsp=eJyrVkrOzytJrSgJqSxIVbJSKk5NLErOUNJRKkgsSswtVrKqVirOLypxqgTKlWWmljvnl%2BaVAKVBgv5FKalFQPGU1OJksI50kAnGZiYgTmpRAIRvAeKmZBYX5CRWghWXJGbmKNXWAgDocCf1

Question is, could the F/O (who was, according to the report, pilot flying) have inadvertently activated the engine cut-off by memory, while thinking they were going for the cowl flap setting from a former type? Even so, why you would touch the cowl flaps on a climb, especially in hot weather as it was on the day. Additionally, based on his CPL date I assume it has been several years since he flew such a type.

Just thought I'd throw it out there.

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

 

[RSD]

The only way that I think I could move them in that time frame would be to use both hands, one for each switch. And even then I think it would take longer. Of course, I'm assuming the locking mechanism is functioning as I'm used to...

If both hands were used then that would probably require the torso to rotate to get the left hand across far enough to do this - so shoulders would rotate and probably move upper body and head forward slightly and across towards the other pilot - I think it would be pretty hard for the pilot flying to miss this.

I haven't read the report yet, but to me it is sounding like something tripped out both engines - a short or something like that.

 

[RSD]

And again, the classic is the oxygen tank failure on QF30. Never happened before in aviation history, and yet, it still did.

And doesn't normally happen to cylinders in other industries either - especially a failure of the base of the cylinder. Known causes of cylinder failures in the diving industry include -

• corrosion - unlikely in the QF30 event as the cylinder had only been visually examined and hydrostatically tested just two months prior
• valve with the wrong thread type fitted - sounds stupid but it has happened - actual cylinder didn't fail though - valve just launches out - not relevant to QF30
• getting too hot while being filled - not relevant to QF30
• neck cracks in one brand of aluminium cylinders - not relevant to QF30
• being exposed to a fire - not relevant to QF30

I've never ever heard of a cylinder's base failing apart from the QF30 O2 cylinder.

 

[QF WP]

Just listened to Juan Brown's YT channel (brancolirio) and being a pilot, he makes some interesting points about the timeline and actions. Struggling to see how it was pilot induced changes, but even more confused if it wasn't. Might mean a re-look at the IT behind the decision making process.

If I was flying on a 787, I'd be asking for the whole bottle of champagne, until the cause(s) is/are fund and actioned.

 

[tgh]

I understand the challenges for the pilots here in accepting the simple english words.. but the likely process appears clear enough.

 

[Aussie_flyer]

Unless I saw it happening, I don’t think I’d ever get to that conclusion. And if I did see him, it wouldn’t be followed by a question.

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

Anyway you guys keep debating it. It seems clear to me.

 

[jase05]

Anyway you guys keep debating it. It seems clear to me

Nothings always as clear as it seems and some healthy debate is fine and informative. Many of us enjoy reading the thoughts of actual pilots

 

[DC3]

At this stage I'm inclined to wait for the official reports or anything from verifiable sources …

 

[Daver6]

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

 

[Saab34]

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 understand many airlines are starting to do this. Some are held back because of union pushback.

 

[Aussie_flyer]

Nothings always as clear as it seems and some healthy debate is fine and informative. Many of us enjoy reading the thoughts of actual pilots

Nothing? That's a stretch

 

[Saab34]

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.