2025-06-12T12:32:00
permalink Post: 11899161
A few have suggested double engine failure due to contaminated fuel, but we've seen historically that the equal likely (or perhaps more likely) reason for a double engine "failure" is accidental shutdown of the wrong engine.
2025-06-12T12:42:00
permalink Post: 11899169
A
True. We won\x92t know until the CVR and Flight Data recordings have been analysed. I think these will give a clear indication of what happened. The airport has reopened so I assume there\x92s no fuel contamination risk.
1 user liked this post.
2025-06-12T13:16:00
permalink Post: 11899202
Just to confirm.
The 787 is an aircraft which likes to, performance wise, use all of the available runway for takeoff. Sometimes you can be sat in the 787 and as you are rolling down the runway, you start wondering if Rotate has been called or not. It loves taking up all of the runway.
Nevertheless, there are some interesting speculations over on X. One guy even claimed the Captain was in the lavatory during the accident...
Many people have noted what appears to be the RAT deployed in the video footage suggesting dual engine failure. Possible wrong engine shutdown? But who diagnoses and actions an engine failure and shutdown below 400ft?
The 787 is an aircraft which likes to, performance wise, use all of the available runway for takeoff. Sometimes you can be sat in the 787 and as you are rolling down the runway, you start wondering if Rotate has been called or not. It loves taking up all of the runway.
Nevertheless, there are some interesting speculations over on X. One guy even claimed the Captain was in the lavatory during the accident...
Many people have noted what appears to be the RAT deployed in the video footage suggesting dual engine failure. Possible wrong engine shutdown? But who diagnoses and actions an engine failure and shutdown below 400ft?
2025-06-12T15:21:00
permalink Post: 11899332
Originally Posted by
Golfss
or one failed, and the other unfortunately shut down.
12 users liked this post.
2025-06-12T15:29:00
permalink Post: 11899341
Absolutely. I just have no idea however how Air India train their persons to do memory items. Our brains can do very interesting things in stressed times, which as an experienced skipper I\x92m sure you\x92ll be aware of
2 users liked this post.
2025-06-12T18:44:00
permalink Post: 11899592
2025-06-12T22:02:00
permalink Post: 11899778
OK, I promised some informed speculation when I got back, so here goes:
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
Last edited by T28B; 12th Jun 2025 at 22:21 . Reason: white space is your friend, and is reader-friendly
33 users liked this post.
2025-06-13T02:34:00
permalink Post: 11899935
Would not be the first time that an accident has uncovered unintended consequences of a particular fallback configuration that was never able to be checked by either/any of Airbus, McDD or Boeing developmental test-pilots. Thinking of the automatic thrust augment/restoration on the MD81 (regn OY-KHO) that crashed 27Dec91 near Gottrora in Sweden (double engine failure). Design Boffins failed to realize that ice-sheet ingestion (sliding off the wings to be ingested by both rear-mount engines) would not benefit at all from each engine hiccup causing a continual uprating of the other (and vice-versa). To be found/uncovered in a simulator you would have to be testing various pilot inadvertencies (rather than rote expected actions). Then again, don't always believe the outcomes to be seen in a simulator. They don't necessarily faithfully emulate what would happen systems-wise in an aircraft... particularly when it comes to complex materiel failure modes or illogical sequiturs (e.g. MCAS)
So, if such an untestable circumstance were to happen to a competent crew and they were to inadvertently shut-down the wrong engine (and then/were in "clean-up mode":
a. The residual hyds would break the downlocks - but not retract the gear (and it would appear to be still selected down)
b. The alternate flaps might start to retract (gear downlocks not being now "made") once selected, but the slats remain out.
c. the RAT would deploy
The point at which all thrust ceases (and the climb vector flattens/reverses) is easily seen
in the video shot from the 6:30 clock position from about a km away. It's readily apparent.
An engine failure just off the runway after V1 in a fully loaded 787-8 in high ambient temperatures would assuredly have a crew thinking about a "toute suite" shutdown of a misbehaving donk. That's human nature. When the PERF is quite sluggish you will be thinking that a quick clean-up of the situation is certainly called for. That's just human nature unfortunately, particularly when you are under the time compression of dire circumstance (and the airframe is performing like a lame dog, just due to the environmentals and the early failure). I think that what the pilot reportedly said to ATC in his Mayday bears that out as being his instant mindset (quite clearly). Been in that "fools rush in" circ myself. You just have to "sit on your hands" and fly the beast.
But then again, if the RAT was NOT found deployed, then it's a case of the right seat mistakenly sucking in the flaps and slats... and that will do it... whatever the power/TOGA might be.
https://tinyurl.com/4zzkeeud
Rotation +33s
Mayday call +44s, circa 300 ft altitude (ADS-B)
Peak altitude +49s, 625 ft (Flightradar24)
Impact +58s, crash site 1.6 km from runway
So, if such an untestable circumstance were to happen to a competent crew and they were to inadvertently shut-down the wrong engine (and then/were in "clean-up mode":
a. The residual hyds would break the downlocks - but not retract the gear (and it would appear to be still selected down)
b. The alternate flaps might start to retract (gear downlocks not being now "made") once selected, but the slats remain out.
c. the RAT would deploy
The point at which all thrust ceases (and the climb vector flattens/reverses) is easily seen
in the video shot from the 6:30 clock position from about a km away. It's readily apparent.
An engine failure just off the runway after V1 in a fully loaded 787-8 in high ambient temperatures would assuredly have a crew thinking about a "toute suite" shutdown of a misbehaving donk. That's human nature. When the PERF is quite sluggish you will be thinking that a quick clean-up of the situation is certainly called for. That's just human nature unfortunately, particularly when you are under the time compression of dire circumstance (and the airframe is performing like a lame dog, just due to the environmentals and the early failure). I think that what the pilot reportedly said to ATC in his Mayday bears that out as being his instant mindset (quite clearly). Been in that "fools rush in" circ myself. You just have to "sit on your hands" and fly the beast.
But then again, if the RAT was NOT found deployed, then it's a case of the right seat mistakenly sucking in the flaps and slats... and that will do it... whatever the power/TOGA might be.
https://tinyurl.com/4zzkeeud
Rotation +33s
Mayday call +44s, circa 300 ft altitude (ADS-B)
Peak altitude +49s, 625 ft (Flightradar24)
Impact +58s, crash site 1.6 km from runway
Last edited by bbofh; 13th Jun 2025 at 07:53 .
1 user liked this post.
2025-06-13T03:02:00
permalink Post: 11899948
OK, I promised some informed speculation when I got back, so here goes:
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
Very hot day, so far past breakpoint, N1 Max sensitive to TAT. Any TAT or DT latching (can't recall if) would be cleared - if at 400 ft AGL, which may not have been attained here.
2025-06-14T23:03:00
permalink Post: 11901937
Just to confirm.
The 787 is an aircraft which likes to, performance wise, use all of the available runway for takeoff. Sometimes you can be sat in the 787 and as you are rolling down the runway, you start wondering if Rotate has been called or not. It loves taking up all of the runway.
Nevertheless, there are some interesting speculations over on X. One guy even claimed the Captain was in the lavatory during the accident...
Many people have noted what appears to be the RAT deployed in the video footage suggesting dual engine failure. Possible wrong engine shutdown? But who diagnoses and actions an engine failure and shutdown below 400ft?
The 787 is an aircraft which likes to, performance wise, use all of the available runway for takeoff. Sometimes you can be sat in the 787 and as you are rolling down the runway, you start wondering if Rotate has been called or not. It loves taking up all of the runway.
Nevertheless, there are some interesting speculations over on X. One guy even claimed the Captain was in the lavatory during the accident...
Many people have noted what appears to be the RAT deployed in the video footage suggesting dual engine failure. Possible wrong engine shutdown? But who diagnoses and actions an engine failure and shutdown below 400ft?
2025-06-15T14:35:00
permalink Post: 11902509
My first post here...I feel I need to, due to some posts I have read. As a 787 pilot who has flown Embraer, Airbus, 767 and the 787-8/-9, I am saddened by many of the posts on this thread.
Some of you should be ashamed.
Blaming the pilots before anyone has any idea what transpired.Short takeoff, improper flap/no flap setting, retracting the flaps instead of the gear, shutting down the wrong engine. In ANY other situation these actions would be laughable, and an insult to proffessional pilots the world over. Some commenting about the flaps even after pictures have shown that the flaps are extended. Also numerous people posting regarding shutting the wrong engine being shut down without any evidence to back this up. Videos clearly showing that the RAT was extended indicates that something very serious/catastrophic happened prior to this hull loss. People...this is the Proffessional Pilot's Rumour Network...Not the National Enquirer!!! I would urge everyone to WAIT for the report. Unbelievable.
Some of you should be ashamed.
Blaming the pilots before anyone has any idea what transpired.Short takeoff, improper flap/no flap setting, retracting the flaps instead of the gear, shutting down the wrong engine. In ANY other situation these actions would be laughable, and an insult to proffessional pilots the world over. Some commenting about the flaps even after pictures have shown that the flaps are extended. Also numerous people posting regarding shutting the wrong engine being shut down without any evidence to back this up. Videos clearly showing that the RAT was extended indicates that something very serious/catastrophic happened prior to this hull loss. People...this is the Proffessional Pilot's Rumour Network...Not the National Enquirer!!! I would urge everyone to WAIT for the report. Unbelievable.
11 users liked this post.
2025-06-15T22:45:00
permalink Post: 11902924
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
3 users liked this post.
2025-06-15T22:56:00
permalink Post: 11902933
Also there is no asymmetry visible in any of the videos.
2025-06-15T23:19:00
permalink Post: 11902951
Originally Posted by
Seven-Five
If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures...
Originally Posted by
EDML
Who would start the engine out procedure at just 100-200ft AGL? No airline teaches that and it doesn't have any advantage.
3 users liked this post.
2025-06-16T00:11:00
permalink Post: 11902995
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
4 users liked this post.
2025-06-16T01:18:00
permalink Post: 11903027
Originally Posted by
Seven-Five
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything.
Originally Posted by
T28
In that poster's defense, you will find that they joined PPRuNe in 2002, and their original profile entry was 767.
The upgrade to 777 between then and now is within reason.
The upgrade to 777 between then and now is within reason.
Increasingly, the posts in this thread are becoming more ridiculous as time goes on. The hampsterwheel bearings will soon explode. IMO it should be locked.
6 users liked this post.
2025-06-16T03:43:00
permalink Post: 11903084
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I originally wondered about that ... until an old colleague sent me this short clip of a triple kicking up dust rotating in the same location
For your consideration: (20 second clip)
1 user liked this post.
2025-06-12T22:02:00
permalink Post: 11903414
Air India Ahmedabad accident 12th June 2025 Part 2
OK, I promised some informed speculation when I got back, so here goes:
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
Disclaimer: never worked the 787, so my detailed knowledge is a bit lacking.
First off, this is perplexing - especially if the RAT was deployed. There is no 'simple' explanation that I can come up with.
GEnx-1B engines have been exceptionally reliable, and the GE carbon composite fan blades are very robust and resistant to bird strike damage (about 15 years after the GE90 entry into service, I remember a GE boast that no GE90 (carbon composite) fan blades had needed to be scrapped due to damage (birdstrike, FOD, etc. - now that was roughly another 15 years ago, so is probably no longer true, but it shows just how robust the carbon composite blades are - far better than the more conventional titanium fan blades).
Not saying it wasn't somehow birdstrike related, just that is very unlikely (then again, all the other explanations I can come up with are also very unlikely
).
Using improper temp when calculating TO performance - after some near misses, Boeing added logic that cross-compares multiple total temp probes - aircraft TAT (I think the 787 uses a single, dual element probe for aircraft TAT, but stand to be corrected) and the temp measured by the engine inlet probes - and puts up a message if they disagree by more than a few degree tolerance - so very, very unlikely.
N1 power setting is somewhat less prone to measurement and power setting errors than EPR (N1 is a much simpler measurement than Rolls EPR) - although even with EPR, problems on both engines at the same time is almost unheard of.
The Auto Thrust (autothrottle) function 'falls asleep' at 60 knots - and doesn't unlock until one of several things happens - 250 knots, a set altitude AGL is exceeded (I'm thinking 3,000 ft. but the memory is fuzzy), thrust levers are moved more than a couple of degrees, or the mode select is changed (memory says that last one is inhibited below 400 ft. AGL). So an Auto Thrust malfunction is also extremely unlikely. Further, a premature thrust lever retard would not explain a RAT deployment.
TO does seem to be very late in the takeoff role - even with a big derate, you still must accelerate fast enough to reach V1 with enough runway to stop - so there is still considerable margin if both engines are operating normally. That makes me wonder if they had the correct TO power setting - but I'm at a loss to explain how they could have fouled that up with all the protections that the 787 puts on that.
If one engine did fail after V1, it's conceivable that they shut down the wrong engine - but since this happened literally seconds after takeoff, it begs the question why they would be in a big hurry to shut down the engine. Short of an engine fire, there is nothing about an engine failure that requires quick action to shut it down - no evidence of an engine fire, and even with an engine fire, you normally have minutes to take action - not seconds.
The one thing I keep thinking about is someone placing both fuel switches to cutoff immediately after TO. Yes, it's happened before (twice - 767s in the early 1980s), but the root causes of that mistake are understood and have been corrected. Hard to explain how it could happen (unless, God forbid, it was intentional).
13 users liked this post.
2025-06-16T00:11:00
permalink Post: 11903728
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
1 user liked this post.
2025-06-16T03:43:00
permalink Post: 11903739
Experienced 777 driver. Have tried to solve the puzzle. Looked carefully at the video in this article many times - see below and use full screen.
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I might see a small puff of smoke and a smoke-ring just before they pass the shed. Indications of en enginefailure. I also see the wings tilt briefly - a few degrees - towards left. Correct procedure after enginefailure is to tilt the wings about 3 degrees toward the engine that is still running. I also see them climb at a - it seems - too high angle for the actual conditions if engine has failed. That will kill the nescessary engineoutspeed in a few seconds and be hard to recover from. If - and I say if - they in this stressed situation managed to shot down the wrong engine following the engineout procedures the RAT would come out. That would probably preoccupy them so much they forget everything about gear and flaps.. It is a situation I believe most experienced 777 / 787 pilots would recognise as a possibility and would explain everything. But this is pure speculation. Lets wait and see what the investigation teams find out...
https://www.aerotime.aero/articles/a...w-so-far-crash
I originally wondered about that ... until an old colleague sent me this short clip of a triple kicking up dust rotating in the same location
For your consideration: (20 second clip)
1 user liked this post.