Posts about: "Engine Failure (All)" [Posts: 410 Pages: 21]

Gary Brown
2025-06-17T11:43:00
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Post: 11904233
Originally Posted by framer
There is a possibility that doesn\x92t get much air time on this forum that satisfies all the \x91facts\x92 ( pprune facts mind you), and requires less mental gymnastics to believe than many of the theories put forward. I\x92m not saying it\x92s what happened at all but it seems much more likely than a TCMA fault to me.
This link is to a Japanese report on a Jetstar 787-8 with GE engines that had both engines drop below idle while airborne due to magnesium salts effecting the operation of the FSV spools. The Magnesium salts came from a biocide dose by maintenance two days earlier.
For some reason I can\x92t paste the link but if you google JTSB the report number is AI2020-2.
I think it\x92s quite easy to imagine that a simple maintenance error ( 1000ppm instead of 100ppm) combined with extremely bad luck on timing lead to this accident.
I think I\x92m favouring a theory like this for its simplicity and the fact that fuel is the elephant in the room when you are dealing with a dual engine failure.
In that report, the factual conclusion is:

4. PROBABLE CAUSES
In this serious incident, it is highly probable that, when the Aircraft was descending for
landing, there occurred oscillation in rpm of each engine causing both engines to temporarily fall
below idle at separate times because Residue primarily composed of magnesium salts accumulated
in spools impeded movement of spools that involved in fuel metering of both engines.
(emphasis added)

and the narrative taken from the pilots is that while they happened in short order, the engine issues were not simultaneous. Not to say they couldn't be simultaneous, but they weren't. Also, the problems arose in the descent, as the engines were throttled back. Again, not to say it couldn't happen in the take-off, under full power.

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Lord Farringdon
2025-06-17T12:21:00
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Post: 11904253
Originally Posted by OldnGrounded
It seems pretty unlikely that a bird strike that took out both of those very big engines simultaneously would not have been fairly obvious in ways that nearby observers (e.g., the crew, ATC, airport personnel?) would have noticed. Possible, of course, but I don't think we've seen any evidence that points in that direction. Also, for what it's worth, the Times of London June 15 story " New clues point to engine failure for cause of Air India plane crash " cited here in the closed thread includes this:



A poster in the closed thread pointed out, properly I think, that the Times shouldn't be relied upon for presentation or interpretation of technical information. Like most general news organizations, their reporters and editors (mostly) just don't have the background to assess, filter and explain complex processes and technology. Unlike many, though, the Times can generally be relied upon to seek appropriate sources and report accurately what those sources say. I think it's very likely that Indian authorities have ruled out a bird strike, and I also think those authorities are competent to make that decision.
Thanks for straightening me out on that one. Strange though that bird strike theory was ruled out so quickly without examining the wreckage or hearing the CVR? And still, the video potentially shows an right engine surge on the runway. If not a bird strike, then for what reason? Maybe I'm just seeing things since no one else seems to see this so I'll leave it there.

The second box has been recovered and the CVR is being analyzed so hopefully they will give an interim update shortly.
McDoo
2025-06-17T12:50:00
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Post: 11904275
What if?

Originally Posted by Squawk7700

Perhaps?

  • Takeoff proceeded normally, TOGA used.
  • Autothrottle entered HOLD mode at 80 knots .
  • VNAV or FLCH was NOT engaged after liftoff.
  • Pilot assumed A/T was managing thrust, but it wasn\x92t.
  • Pilot focused on pitch/flying manually.
  • Thrust stayed fixed or decayed (if levers were moved).
  • Speed decayed, aircraft climbed too steeply, energy bled off.
  • Pilot assumed engine failure due to poor climb response.
Boeing SOPs typically include a callout at 400 ft like:

"LNAV" - "VNAV" or "FLCH SPD"

To ensure:
  • Proper navigation mode is active
  • Autothrottle resumes thrust management
  • Aircraft transitions smoothly into the climb phase
Do we know yet what stop
altitude was set on the FGP?

Suppose they had left it at zero prior to final departure briefing?

Not 787 rated but is it possible that they selected FLCH after take off and the aircraft targeted the zero altitude selection?

Doesn\x92t explain the RAT deployment but I have a feeling there maybe more than one hole in this Swiss cheese\x85


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OldnGrounded
2025-06-17T13:44:00
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Post: 11904315
Originally Posted by ignorantAndroid
I'm honestly mystified by the obsession with TCMA. The FADECs control almost every aspect of the engines, so there must be numerous ways they could cause a failure or uncommanded shutdown. So, even if we assume that the engines failed due to faults in the FADECs, why assume that TCMA would be involved?
I think you may be inferring something that isn't actually true. It certainly isn't true in my case. Wanting to explore the details of a function known to be designed to shut down engines, in a case where unexplained shutdown of engines appears to be a likely cause or contributing factor, doesn't suggest that we are assuming TCMA is involved. It's just exploring the details of a a function that is designed to do that and doesn't put on a light, smoke and sound show, or produce obvious debris and residue, when it does.

I think those of us who are persistently trying to learn the details of the sensor inputs to and logic of TCMA (I prefer that characterization to "obsessed with") understand quite well the points you make here — at least those of us whose interest survives in this new thread. However, I at least, and I believe others as well, have also come to the tentative conclusions that (a) the accident aircraft had engines providing little to no useful thrust from nearly the first moments after rotation, and (b) the only possible reasons for that which have been considered here so far involve the sudden and approximately simultaneous shutdown of those engines, most likely by interruption of fuel flow (because that's one of the very few things we know that can do that without producing big bangs, flames and smoke, etc.).

Surely it's more logical to simply posit that some unspecified bug in the FADEC software caused the failure. That bug could be related to TCMA, but it could just as easily involve any one of the dozens of other subroutines that likely exist.
I don't agree that it's more logical to posit that something we don't know about has shut down the engines rather than something that we do know about that is intended to shut down engines. Do you know of other routines/subroutines in the FADEC that shut down fuel supply?

Various posters seem to assume that all it takes is an incorrect air/ground signal, and the engines would shut down.
I certainly don't assume that and I haven't seen posts from others (that I consider serious and reasonably well-informed) that "seem to assume" that.

But in fact it would also require the FADECs to read the thrust levers as being at or near idle... AND the engines failing to respond to closure of the fuel metering valve.
Yes, we know that.

I've read the entirety of both threads, and I haven't seen anyone even attempt to explain how a malfunction within the airframe could cause both of those things to occur on both engines (or even one engine!).
Right, and you won't see a serious attempt to do that until we know, at least, what specific sensor inputs the TCMA function uses to determine the air/ground state of the aircraft and the logic that uses those to make the determination.


Last edited by OldnGrounded; 17th Jun 2025 at 13:46 . Reason: Formatting

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JRBarrett
2025-06-17T13:50:00
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Post: 11904318
Originally Posted by ignorantAndroid
Various posters seem to assume that all it takes is an incorrect air/ground signal, and the engines would shut down. But in fact it would also require the FADECs to read the thrust levers as being at or near idle... AND the engines failing to respond to closure of the fuel metering valve. I've read the entirety of both threads, and I haven't seen anyone even attempt to explain how a malfunction within the airframe could cause both of those things to occur on both engines (or even one engine!).
Many years ago I maintained a Hawker 1000 business jet equipped with PW305 engines with FADEC. The fuel control did not have a separate switch to control fuel flow to shut down the engines. Shutdown was accomplished by pressing a release on the power levers allowing the lever to be pulled past the idle stop all the way to the cutoff position.

One day upon returning from a flight, the crew pulled both power levers to cutoff. The right engine shutdown immediately as expected, but the left engine kept running. By the time we in maintenance got out to the airplane, the engine finally shutdown by itself.

Troubleshooting found the cause of the problem. The cutoff position of the power lever closed a micro switch that sent a ground to the FADEC. That ground went through two discrete wires. One went directly to one input on the FADEC. The other went through a squat switch on the main gear leg to a second input on the FADEC. The engine would only shutdown immediately if both inputs went to ground simultaneously. If only one input went to ground, the FADEC would delay shutdown for 30 seconds. This was to protect against an inadvertent movement of the power lever to the cutoff position in flight causing an immediate shutdown.

The squat switch on the left gear leg had failed in the open position, causing the problem.

I am wondering if more modern FADEC engines have similar protections against immediate shutdown in the air? I can see why the designers of the Hawker implemented the system the way they did, because the shutdown command was integral to the power lever, and it potentially could be pulled to the cutoff position in flight by an inadvertent release of the locking mechanism that would normally prevent it from going past the idle stop, whereas modern FADEC engines like found on the 787 have a discrete locking switch.

But, if a similar protection against immediate shutdown does exist in the 787, would the engines keep running for a period of time (in the air) even if the fuel control switch was accidentally or deliberately moved to \x93off\x94?


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Capn Bloggs
2025-06-17T14:17:00
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Post: 11904336

Originally Posted by Squawk7700
Perhaps?

Originally Posted by Squawk7700
  • Takeoff proceeded normally, TOGA used.
  • Autothrottle entered HOLD mode at 80 knots .
  • VNAV or FLCH was NOT engaged after liftoff.
  • Pilot assumed A/T was managing thrust, but it wasn’t.
  • Pilot focused on pitch/flying manually.
  • Thrust stayed fixed or decayed (if levers were moved).
  • Speed decayed, aircraft climbed too steeply, energy bled off.
  • Pilot assumed engine failure due to poor climb response.
Boeing SOPs typically include a callout at 400 ft like:

"LNAV" - "VNAV" or "FLCH SPD"

To ensure:
  • Proper navigation mode is active
  • Autothrottle resumes thrust management
  • Aircraft transitions smoothly into the climb phase
Some questions, if I may:
VNAV or FLCH was NOT engaged after liftoff.
When is the crew expected to do this? Wouldn't it be armed prior to commencing the takeoff so that it (one or the other) would engage automatically?

Pilot assumed A/T was managing thrust, but it wasn’t.
How does the 787 "manage thrust" after takeoff? The jet has only just left the ground; surely the throttles would be at maximum power and pitch would be used to attain and maintain V2 until the end of the second segment.

Pilot assumed A/T was managing thrust, but it wasn’t.
Are you saying the pilot( s ) just sat there while the ATS reduced the thrust (because is all it could have done, as it was at maximum for the actual takeoff).

Thrust stayed fixed or decayed (if levers were moved).
Fixed on what? Or did it "decay" because the PF pulled the throttles back?

​​​​​​​Speed decayed, aircraft climbed too steeply, energy bled off.
There is no evidence the jet climbed too steeply; I assume you saw the granular FR24 plot (from FR24 itself) which showed the initial flight path of this one was in the middle of the range, and the video clearly shows a normal initial climb and deck angle before "the @#$% dropped out of it".

​​​​​​​Pilot assumed engine failure due to poor climb response.
So BOTH pilots just sat there, didn't pull the gear up, did nothing else and crashed it (pretty well, I might add, with superb pitch control right to the last second).

Boeing SOPs typically include a callout at 400 ft like:
"LNAV" - "VNAV" or "FLCH SPD"
To ensure:
  • Proper navigation mode is active
  • Autothrottle resumes thrust management
  • Aircraft transitions smoothly into the climb phase
Interesting but totally irrelevant as the jet never got above 200ft.

You're clearly implying a complete ballsup by the crew, making multiple serious mistakes or errors of omission.

Last edited by T28B; 17th Jun 2025 at 15:40 . Reason: formatting clean up

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Icarus2001
2025-06-17T14:35:00
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Post: 11904353
We know there was likely simultaneous dual engine failure very near Vr.
We DO NOT know that. If that had occurred how did the aircraft achieve initial climb?

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FlightsofFancy
2025-06-17T15:14:00
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Post: 11904389
incorrect or no data

Originally Posted by Ollie Onion
Firstly, condolences to all those involved\x85.as someone who also 'trains and checks' pilots and also has many years of Safety Investigation within large airlines it is a semi regular occurrence to depart with incorrect or no data.

Tiger took off in Sydney with NO data in the FMGC,
Singapore had a tail strike in AKL after inserting the ZFW as the TOW
Emirates almost crashed in MEL for similar reasons.

Not saying that this happened here

Air NZ a few years ago almost put a 787 in the water out of Rarotonga as they had 100' in the FCU, took off, engaged autopilot and the aircraft pitched down and thrust came off, pilots recovered it at 60agl.
Emirates has done similar, so these things happen.
If this happens, and hasn\x92t yet led to a fatal accident, is it possible over say incorrect or no data could lead to a fatal accident (not saying it happened here).

Could incorrect or no data coupled with other issues (eg hydraulics, electrical or engine failure) lead to a situation that might have been recoverable with the correct data being unrecoverable?
Xeptu
2025-06-17T15:39:00
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Post: 11904404
Originally Posted by Piper.Classique
There are several videos of the survivor being interviewed in India, all of them as one might expect, in the language of the country, with English subtitles. As Mr Ramesh is a British national, many years in the UK, I did wonder if there have been any interviews in English, in which I expect he is fluent. That might/should eliminate errors in translation and make his testimony more clear. I can't find any on the net.
I don't think it will make any difference, english still isn't his first language and the bang he heard could be anything from a tail strike, load shift, catastrophic engine failure, rat deployment, initial strike/ impact. He is the luckiest guy on earth, lottery ticket stuff.
rkenyon
2025-06-17T17:19:00
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Post: 11904487
Originally Posted by Magplug
B787 Skipper.... No longer able to sit on my hands!

The joker that published one or other of the fictional accident reports before the dead are even identified needs stringing up by the thumbs.... Well done mods. OK, some of these theories, just bearing in mind the the flight recorder (there is only one FDR + CVR combined) was in the intact section of the undamaged tail and has been with the authorities for almost five days......

- All you guys who are rushing down the TCMA rabbit hole: If it was established that a software error drove both engines to idle without warning, after rotate.... Don't you think the worldwide fleet of B787s would have been grounded by now? Such a glaring failure would be absolutely inescapable on the FDR.

Whatever was wrong with this aircraft was present at rotate, unbeknown to the crew. The fact that no ADs or notices to operators have been issued usually means that the cause is known and the aircraft was serviceable. The statement from a prominent Indian Captain about the skill and tenacity of the crew, right up to the last minute is absolutely laudable. However, the cynic in me says that the way is being paved for some bad news and by that I mean news that will do Air India reputational damage. Expect more management of expectation in the coming days.

I'm still going with
a) Incorrect derate + low Vspeeds or
b) Low altitude capture
Do you stand by your previous assertion :-

Originally Posted by Magplug
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.

- RAT out? Almost impossible, I have seen no quality footage that definitively witnesses the RAT being out. Those who think they car hear a RAT type noise might be listening to a motorcycle passing or similar. It takes a triple hydraulic failure or a double engine failure to trigger RAT deploment. They happily went through V1 without a hint of rejected take off so as they rotated the aircraft was serviceable. These are big engines, they take a long time to wind down when you shut them down. I have never tried it however engine failure detection takes 30s or for the aircraft to react and they were not even airborne that long.

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neila83
2025-06-17T17:38:00
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Post: 11904506
Originally Posted by Magplug
B787 Skipper.... No longer able to sit on my hands!

The joker that published one or other of the fictional accident reports before the dead are even identified needs stringing up by the thumbs.... Well done mods. OK, some of these theories, just bearing in mind the the flight recorder (there is only one FDR + CVR combined) was in the intact section of the undamaged tail and has been with the authorities for almost five days......

- All you guys who are rushing down the TCMA rabbit hole: If it was established that a software error drove both engines to idle without warning, after rotate.... Don't you think the worldwide fleet of B787s would have been grounded by now? Such a glaring failure would be absolutely inescapable on the FDR.

Whatever was wrong with this aircraft was present at rotate, unbeknown to the crew. The fact that no ADs or notices to operators have been issued usually means that the cause is known and the aircraft was serviceable. The statement from a prominent Indian Captain about the skill and tenacity of the crew, right up to the last minute is absolutely laudable. However, the cynic in me says that the way is being paved for some bad news and by that I mean news that will do Air India reputational damage. Expect more management of expectation in the coming days.

I'm still going with
a) Incorrect derate + low Vspeeds or
b) Low altitude capture
Maybe you should have kept sitting on your hands, theory a) in particular is about as risable as the last one you posted. Do you still think engine failure takes 30 seconds for the plane to react?! Thanks to rkenyon for alerting us not to take your post seriously. You still don't believe the RAT was out despite the in depth audio analysis done by an expert in the field. You still think its a motorbike?!

Given they took off at a perfectly normal point, at a perfectly normal speed, I don't see how you come to incorrect derate and low v speeds, or how on earth that would lead to a normal takeoff followed by sinking?

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Yo_You_Not_You_you
2025-06-17T20:20:00
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Post: 11904623
Originally Posted by ettore
Aryan Asari, the 17-year-old who filmed the crash from his father's rooftop, gave his original interview earlier in the week to BBC Gujarati, i.e in Gujarati language.

I believe they're native speakers professional pilots on Pprune who might have read or could find the original piece. Could they help to clarify Aryan's statements in English?

More of this eyewitness' statements in Gujarati also might NOT have been translated into English. Maybe worth checking for added value. Thanks.
BBC's article quotes him as saying the shaking or moving left and right . But on more fresh interviews he didn't say that . He was assuming the plane was landing since it was his first time there . He came an hour before . He wanted to take video for his friends back at the village . Apparently this is a phenomenon called Misinformation Effect "where well-documented phenomenon in psychology that describes the tendency for post-event information to interfere with and alter a person's memory of an original event."

Grand mother was the one saying it was shaking . She said her location was even closer to the airport . She also said the plane was silent compared to how others make the sound
while above the sound was there , but leaving sound was missing , You know how much Baloon (plane) makes the sound, this was weird .
Maybe he started incorporating extra information from her and in turn Who know What Information she is getting Misattributed , Overwritten etc herself but her take is also possible take on engine failure.



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Bristolhighflyer
2025-06-17T20:37:00
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Post: 11904641
Originally Posted by Obba
I wonder if those reported eight Air Indian 787-8's pulled in for 'looking at', have had any issues with failed power systems, as in the reported and video of this aircraft, having no IFE systems working.,
I really think this is worth looking at. I keep asking a maintenance engineer to comment on what they'd do if a 787 with these issues presented itself to them on a turnaround shift and whether those faults could be connected to engine failure in some way.

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TURIN
2025-06-17T21:47:00
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Post: 11904697
Originally Posted by Bristolhighflyer
I really think this is worth looking at. I keep asking a maintenance engineer to comment on what they'd do if a 787 with these issues presented itself to them on a turnaround shift and whether those faults could be connected to engine failure in some way.
The short answer is no.
The 787 has a very sophisticated diagnostic system. Faults are presented through a central maintenance computer system accessible either through the flight deck display units or from a laptop plugged in to the aircraft (there is a WiFi option but honestly it's a bit clunky and I've only ever used it once).
All faults are displayed in ATA order as either active, not active or latched faults.
I cannot see how any IFE, lighting, air con or other non power plant related faults could cause the situation that has brought this aircraft down.
The IFE is entirely seperate and has its own independent diagnostic system.

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EDML
2025-06-17T23:37:00
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Post: 11904770
Originally Posted by Lead Balloon
I was struck by a comment in this or the earlier thread that I cannot now find. It was to the effect – I’m paraphrasing – that fuel shut off results in an almost immediate cessation of thrust. (Please correct my paraphrasing if I’m off track.) I was also struck by how quiet the aircraft was in the original video, except for the RAT. (Or was it a motorcycle? Sorry couldn’t resist. Just joking…)

Someone earlier asked how the aircraft could have kept climbing if both engines stopped very late in the take-off roll or shortly after take-off. My answer: Momentum.
tdracer explained that earlier: T/O power to sub idle on fuel shutoff only takes 1s, at most 2s.

Slamming the throttles back is a lot slower as the FCU (on a traditional engine)/FADEC spins down the engine slowly - I suppose to make sure that the airflow through the engine remains stable.

Regarding the momentum: As the first few seconds of the climb were normal compared to previous T/Os of the same flight (speed & altitude, confirmed by comparison of the RAW ADS-B data) I don't believe the engine failure happened before or on lift-off.

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framer
2025-06-18T00:19:00
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Post: 11904793
Regarding the momentum: As the first seconds of the climb were normal compared to previous T/Os of the same flight (speed & altitude, confirmed by comparison of the RAW ADS-B data) I don't believe the engine failure happened before or on lift-off.
I agree with this. For all the SLF reading and not posting ( good work!) there is a delay between the end of the takeoff run and the gear being selected up. I fly 737’s so any 78 folk feel free to correct me but it looks like this;
PM: “ V1 ….Rotate”
The PF then begins to rotate the aircraft up to a pre determined attitude which is normally between 13 and 15 degrees. They do this at a rate of between 2 and 3 degrees per second so about 5 or 6 seconds later the aircraft is at its climb out attitude. The PM is then looking at their instruments to confirm that the aircraft has a positive rate of climb, this takes a moment, maybe 1 to 3 seconds then;
PM “ positive rate”
PF: “ gear up”.
So minimum 8 seconds but probably longer between the PM calling “rotate” and the gear being selected up.
The relevance of all that is to say that if you suspect that the gear up cycle has been interrupted by a dual engine failure, then the engines may well have been producing thrust up to an altitude of 50-100ft or so, which ties in nicely with the max height reached, distance travelled etc.
Mods this is clearly not a theory, just info for those who don’t fly airliners to aid understanding.

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Musician
2025-06-18T04:34:00
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Post: 11904895
Question climb rate

Originally Posted by EDML
Regarding the momentum: As the first few seconds of the climb were normal compared to previous T/Os of the same flight (speed & altitude, confirmed by comparison of the RAW ADS-B data) I don't believe the engine failure happened before or on lift-off.
Could you please elaborate on that?

FR24 did do that raw ADS-B data comparison. Remember the GPS position and barometric altitude are sent by the aircraft itself. The altitude is sent in 25 ft intervals, so a shallow curve that is smooth in reality looks janky in the data, due to the rounding of the numbers. From https://www.flightradar24.com/blog/f...rom-ahmedabad/ :
We’ve taken data from AI171 departures for the month prior to the accident flight—including two previous operations by VT-ANB—and overlaid their departure paths on the data from AI171 on 12 June. The accident flight is in red, while all other flights are the blue paths. The data shown here is the uncalibrated barometric altitude, so the data is not above ground level, but it is consistent to itself.
The red line is the accident flight, and it covers approximately 4.3 seconds.
Obviously the altitudes are all uncorrected for barometric pressure, which would've varied with the weather on that day; you kind of have to mentally shift the lines vertically downward. Now I looked for, but couldn't find, the post in the old thread where the rotation was triangulated\xb9, but I remember that it was near the turnoff to the high-speed taxiway, so a few seconds ahead of this ADS-B capture. We only have the video to show us what occurred then.

That means the ADS-B data doesn't really tell us whether the first few seconds of the climb were normal or not.

When we compare the red line to the blue lines, the data tells us the climb rate had already decayed significantly before the accident aircraft passed over the end of the runway, because the red flight path is much more shallow than the blue flight paths.

Please correct me if I'm wrong: to my eye, the data alone does not show that the engines must have failed after rotation, because the data does not demonstrate a normal climb rate.

But likewise, the engines can't have failed much before rotation:
Originally Posted by fdr
This aircraft has got airborne well within the requirements of FAR 25 under which it was certified. It has over 1250m ahead of it passing around 35' based on the video from behind, so the FMC data was not incorrect, the thrust up until after TO was not incorrect, and the CG is not out of range, the time to rotate is within expected range, and the attitude at liftoff is not excessive, the plane is not heavier than expected.
For completeness' sake: you can look at the CCTV video, consider the 787's wingspan a flying 200 ft yardstick, and hopefully agree that the aircraft did not get much higher than 200 ft AAL, if that.

-----
\xb9 I found one of them, anyway. The reference is the CCTV video:
Originally Posted by dragon6172
You can triangulate the camera location using the aircraft holding short for takeoff and the road sign. Then draw a line from there just to the right of the instrumentation building and you'll find the aircraft rotated with about 4000 feet of runway remaining (11000+ runway length).

Last edited by Musician; 18th Jun 2025 at 17:43 . Reason: footnote 1

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steamchicken
2025-06-18T07:26:00
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Post: 11904987
There has been a lot of discussion of the possibility that the crew shut down the wrong engine or misidentified some other problem as an engine failure, usually followed by an assertion that nobody would touch the engines before x feet. PPRuNe's own survey, at the top of this very subforum, found a really high base rate of wrong engine incidents:
  • 31 per cent of the PPRuNe Population reported either having a wrong-engine incident or a close call
  • 61 per cent reported witnessing one
This might be biased upwards by people who have had the experience being more likely to engage with a thread about it and to respond to the survey, although on the other hand the difference between self-reported errors and witnessed ones shows there's also some bias to under-reporting. In the light of those observations you should surely have quite a strong prior that an erroneous engine shutdown is possible.

Also, on the point about sitting on your hands to 400/1000 feet AAL, someone who has already deviated from a standard operating procedure is more likely to go on to make another mistake; that is why the procedure existed in the first place.

As a memo item, here are the survey results:

Q1. Have you ever shut off the wrong engine in the sim?
Yes: 5.4% +0.9%
No: 94.6% -0.9%

Q2. Have you ever ALMOST shut off the wrong engine in the sim?
Yes: 26% -1.0%
No: 74% +1.0%

Q3. Have you ever witnessed a colleague shut off the wrong engine in the sim?
Yes: 16% +1.0%
No: 84% -1.0%

Q4. Have you ever witnessed a colleague ALMOST shut off the wrong engine in the sim?
Yes: 45% +2.0%
No: 55% -2.0%

Link to original post

Senior Pilot

Last edited by Senior Pilot; 18th Jun 2025 at 07:35 . Reason: Add link

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Bap7788
2025-06-18T11:50:00
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Post: 11905173
Hi all,

Disclaimer: I read this thread from hour 1, still scratching my head regarding perf though.

I know sound analysis points to higher odds being a dual engine failure with RAT deployed, however I still have some questions if anyone is available to enlighten.

So, my questions is related to T/O performance.

Is it possible on the 787 to calculate perf in the OPT for F15/20 T/O, and to enter F5 T/O speed on the FMC ?

By that I mean do normal procedure, but at the point where you are suppose to enter flaps, CG speed ect…. You, out of habit (if F5 is indeed a habit on the 787) enter F5, but F15/20 speeds ? Or would there be a warning that you have manually inputed speeds that are not correct for the selected flaps and conditions inputed in the FMC ?

Thanks for the help !
syseng68k
2025-06-18T11:58:00
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Post: 11905180
Lead Balloon:

The requirement for TCMA may have been specified by Boeing, but that doesn' t tell us who designed and built the solution in this case, though it must have been a collaborative effort between the two parties. Anyway, TCMA may be a red herring, since we still have not defined what, if any, other sources would have authority to issue an engine shutdown command

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