Air India plane crash

[knot4u]

So where in there does it say what thrust was doing when they did that? Did they shut down perfectly good engines? Or did they rollback for some reason?

If you honestly think that report would mention the cut off switches doing something odd and not mention the PLAs doing something untoward you're really grasping at straws.

 

[knot4u]

I don't remember reading anything in there that directly discussed engine operating parameters, other than the part talking about the thrust levers being forward in the takeoff position (or some words to that effect). Agree with what you are inferring here, but it isn't explicitly stated that the engines were operating normally before the switches moved to cutoff....unless I missed something skimming.

To me, it seems quite strange that someone would just accidentally do this. I dunno, stranger things have happened, but normally people do things for a reason, even if that reason proves to be an erroneous perception. But who knows, people do crazy things with flap levers in WB airplanes sometimes too. Fast hands?

I'd say the fact that they got to 180 knots is indicative of the engines running properly.

 

[BEEF SUPREME]

I don't remember reading anything in there that directly discussed engine operating parameters, other than the part talking about the thrust levers being forward in the takeoff position (or some words to that effect). Agree with what you are inferring here, but it isn't explicitly stated that the engines were operating normally before the switches moved to cutoff....unless I missed something skimming.

To me, it seems quite strange that someone would just accidentally do this. I dunno, stranger things have happened, but normally people do things for a reason, even if that reason proves to be an erroneous perception. But who knows, people do crazy things with flap levers in WB airplanes sometimes too. Fast hands?

I'm assuming an engine anomaly would have been in the report and the focus of the investigation. The engine shutting down when commanded to do so by a pilot using a switch that requires specific manipulation is not an anomaly.

 

[///AMG]

I'd say the fact that they got to 180 knots is indicative of the engines running properly.

Yes, I would agree with you

 

[Malko]

No. If a flight attendant farts in their general direction of turbulence rears its ugly head they immediately fall down to the cutoff position, because of gravity. Are you serious?

It was a simple question that was asked. Was wondering if it was just more pressure sensitive or a separate action of lifting up and over.

You know…a wise man told me once….”Sometimes it’s better to keep your mouth shut and let people think you’re fool than to open your mouth and prove it”.

Thanks for playing though

 

[///AMG]

I'm assuming an engine anomaly would have been in the report and the focus of the investigation. The engine shutting down when commanded to do so by a pilot using a switch that requires specific manipulation is not an anomaly.

Yeah, concur. I rewrote a portion of my previous to be more clear. I'm specifically curious about what led one or both of them to decide the start levers needed to go to cutoff. It just seems unlikely to me that this would be something someone could do by accident. I know I don't put my hands anywhere close to those things after I start the engines.

 

[BEEF SUPREME]

Yeah, concur. I rewrote a portion of my previous to be more clear. I'm specifically curious about what led one or both of them to decide the start levers needed to go to cutoff. It just seems unlikely to me that this would be something someone could do by accident. I know I don't put my hands anywhere close to those things after I start the engines.

We probably won't find that out for a long time. Or if it was intentional we may never find it out at all. I believe an Air Egypt crash may have been cause by pilot intent but political issues caused the investigation to not determine that as the cause.

 

[BEEF SUPREME]

Yeah, concur. I rewrote a portion of my previous to be more clear. I'm specifically curious about what led one or both of them to decide the start levers needed to go to cutoff. It just seems unlikely to me that this would be something someone could do by accident. I know I don't put my hands anywhere close to those things after I start the engines.

The specific Air Egypt crash and details on why the investigation was not allowed to determine the cause at the level you're asking about:

EgyptAir Flight 990 - Wikipedia

en.wikipedia.org

 

[Inverted]

If you honestly think that report would mention the cut off switches doing something odd and not mention the PLAs doing something untoward you're really grasping at straws.

I don't have to think anything. It doesn't mention anything regarding WHY those switches might have been switched to cutoff.

I'm not grasping at anything, I simply want more info.

 

[///AMG]

We probably won't find that out for a long time. Or if it was intentional we may never find it out at all. I believe an Air Egypt crash may have been cause by pilot intent but political issues caused the investigation to not determine that as the cause.

Oh yeah, definitely could be hard to conclusively put a bow on that one, unless the FDR feed is pretty clear on what happened.

 

[Cherokee_Cruiser]

I agree. My point is what actually caused the engines to shut down? It's not as if the FDR actually records the physical position of the switches, it records their output (run or cutoff) digitally and that's great but weird things happen that seem so inconceivable that the explanation is the stuff books are written about. I'd agree that at this point one of two things happened, either someone reached over and shut the engines down or something else effected those switches that shut the engines off. I'm not ready to place blame until we know all of the facts. I guess because Boeing and the NTSB has been involved and no emergency AD's or newsletters have been issued it looks like it must've been one of the crew but I'm not an expert and I'll wait to hear what they have to say after they've chased down every other possibility. Their job isn't trying to place blame, it's finding the actual cause of an accident.

These switches are similar to a MAX, and while I’m no auditory expert, there does seem to be a click-type noise when you move to/from cutoff to idle. When you move it, it clicks into the detent. If they’re saying switches moved, there’s probably an auditory backup to their assessment picked up on the CVR.

 

[Cherokee_Cruiser]

The engine fuel controls were switched from RUN to CUTOFF at approximately the same time, but each engine's controls were switched from CUTOFF to RUN about four seconds apart.

Just a guess:


Since the PF was FO he did not cut switches. CA does. Those cutoff are 1 second apart. Quick. FO rotates with both hands. Then questions CA why he shut engines off. Then removes one hand from yoke, while handflying, throwing them back on. I can easily see that taking 4-5 seconds while multi-tasking hand flying the plane.

 

[MikeD]

Just a guess:


Since the PF was FO he did not cut switches. CA does. Those cutoff are 1 second apart. Quick. FO rotates with both hands. Then questions CA why he shut engines off. Then removes one hand from yoke, while handflying, throwing them back on. I can easily see that taking 4-5 seconds while multi-tasking hand flying the plane.

Was it 1 second apart, or .01 seconds apart? If it’s the latter, that’s some extremely fast switchology there.

I hope the systems people on the AAIB are eliminating any electrical or other anomalies with or related to those switches, before focusing on crewmember action, unless there’s something in the CVR not released yet, or any specific outside evidence. that would focus otherwise.

 

[FlyingAccountant]

Just a guess:


Since the PF was FO he did not cut switches. CA does. Those cutoff are 1 second apart. Quick. FO rotates with both hands. Then questions CA why he shut engines off. Then removes one hand from yoke, while handflying, throwing them back on. I can easily see that taking 4-5 seconds while multi-tasking hand flying the plane.

That's my assumption.

It's easy to blame the low hour guy here, but he was PF.

 

[Cherokee_Cruiser]

We don't know if the engines rolled back before the switches were moved to cutoff do we?

Fairly certain the prelim report would have stated such. No, they did not.

 

[Cherokee_Cruiser]

Was it 1 second apart, or .01 seconds apart? If it’s the latter, that’s some extremely fast switchology there.

I hope the systems people on the AAIB are eliminating any electrical or other anomalies with or related to those switches, before focusing on crewmember action, unless there’s something in the CVR not released yet, or any specific outside evidence. that would focus otherwise.

I’d say 1 second. I see the 01 but I think this is a Pakistani/Indian thing.

 

[Cherokee_Cruiser]

I don't remember reading anything in there that directly discussed engine operating parameters, other than the part talking about the thrust levers being forward in the takeoff position (or some words to that effect). Agree with what you are inferring here, but it isn't explicitly stated that the engines were operating normally before the switches moved to cutoff....unless I missed something skimming. To be clear, I do think, and I have thought since the initial video was released, that the engines were functioning normally.....havent seen any evidence whatsoever to conclude otherwise. I'd include the RAT deployment in the category of "not evidence of engine malfunction" as well.

But to me, it seems quite strange that someone would just accidentally do this. I dunno, stranger things have happened, but normally people do things for a reason, even if that reason proves to be an erroneous perception. But who knows, people do crazy things with flap levers in WB airplanes sometimes too. Fast hands?

I think this statement is definitive. Engines were at their takeoff power when the switches were cutoff:




“The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off.”



From their takeoff values is pretty clear. Engines were fine. Right?

 

[inigo88]

I’d say 1 second. I see the 01 but I think this is a Pakistani/Indian thing.

Agreed, silly Europeans and elsewhere use ,01 instead of .01. I would expect the comma in lieu of the decimal point, but if there aren’t either then that should be 1 second.

 

[inigo88]

A couple other notes from the report including past speculation that turned out to be incorrect.

1. The flaps were still in the 5 deg detent, so nobody raised the flaps too early.

2. The gear handle was still down. Another theory that I was intrigued by earlier was a cascading electrical failure initiated by the gear retraction sequence (due to some people looking at the angle of the main gear trucks being off and speculating that the gear retraction sequence had started and then paused at an early stage).

3. If we trust the position of the recovered flap and gear handles and the fuel cutoff switches, one may notice that the throttle quadrant shows the thrust levers in or near the idle position. The report makes no mention of the thrust levers being reduced from takeoff position to idle, which I find curious, because the FDR definitely gets TLA as an input. I wonder when they did that? Were they pulled back prior to moving the fuel control switches to cutoff?

 

[Ben Peters]

3. If we trust the position of the recovered flap and gear handles and the fuel cutoff switches, one may notice that the throttle quadrant shows the thrust levers in or near the idle position. The report makes no mention of the thrust levers being reduced from takeoff position to idle, which I find curious, because the FDR definitely gets TLA as an input. I wonder when they did that? Were they pulled back prior to moving the fuel control switches to cutoff?

I think the report addresses this right above those photos:

The thrust lever quadrant sustained significant thermal damage. Both thrust levers were found
near the aft (idle) position. However, the EAFR data revealed that the thrust levers remained
forward (takeoff thrust) until the impact. Both fuel control switch were found in the “RUN”
position. (fig.13) The reverser levers were bent but were in the “stowed” position.

So maybe they moved aft during the impact?