2025-06-13T12:35:00
permalink Post: 11900461
If lack of power was an issue, this problem started after V1 and likely after liftoff. One working engine would have sufficed to get them out of the runway after V1 and to a relanding, this is a regulatory requirement. That the weight, temperature, air density, obstacle situation and so on allows for this will have been confirmed during the takeoff data calculation.
All we know is that the wings were not creating enough lift for the plane to remain airborne. It's still unclear why without any solid and confirmed information. And it could well be an accumulation of many errors.
2025-06-13T12:42:00
permalink Post: 11900469
1 user liked this post.
2025-06-13T22:13:00
permalink Post: 11900963
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
51 users liked this post.
2025-06-13T22:48:00
permalink Post: 11900976
How would 'all the power come off' at 150ft AAL when the Autothrottle would still be in HOLD mode (until 400ft) and therefore be unable to move?
And should't a genuine B787 captain know this?
And should't a genuine B787 captain know this?
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
2025-06-13T22:59:00
permalink Post: 11900982
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
The engines, however: yes they take a long time to wind down fully , but they don't take long to stop providing thrust if you shut them down or cut the fuel (or indeed have a bird strike). I don't understand why you consider a loss of thrust to be an impossible hypothesis.
There's also a still image above which appears to show a deployed RAT; that's even if we discount the sound track, which might indeed be something else than a RAT, and ignore the sound of the crash being clearly audible despite the lack of engine noise earlier in the video.
5 users liked this post.
2025-06-13T23:09:00
permalink Post: 11900987
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
3 users liked this post.
2025-06-13T23:49:00
permalink Post: 11901007
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
Even though these are big engines with plenty of inertia, when you select engine shut off they spool down very quickly if on load. IE, The generators, two per engine and hydraulic pumps, etc, being driven by the (relatively) small mass of the N2 rotor will drag the speed down very quickly, the gennies will trip offine in seconds, the pumps will quickly reduce flow and pressure.
As for what went wrong.
If the engines have stopped working there has to be a common failure mode, fuel is one but as has been said, no other aircraft has had a problem, as far as we know. FOD? It would have to be something major to shut down two GeNX engines and there would be debris all over the runway, we would know by now.
I have no idea if the RAT has deployed, I can't see it in the video and the noise could be something else.
We shall see.
There is compelling evidence that flaps are set correctly and not retracted inadvertently.
I await further evidence.
Edit to add. LAE 40 years, type rated on 737 to 787 with lots of others in between.
5 users liked this post.
2025-06-13T23:51:00
permalink Post: 11901008
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
the ALT capture is what caught EK\x92s 777 out in DBX right? I still can\x92t think of a logical reason why they continued to allow ALT capture below thrust reduction height (depending on your operator 400-1000 AGL), that seems like a latent threat.
2025-06-14T00:54:00
permalink Post: 11901045
And even more interesting-\x93heaves the aircraft into air with airspeed possibly below V1\x94.
Okaaay\x85 even if V1 = Vr on this occasion, I see no evidence of a rotation at too low a Vr. How could a late rotate mean rotating below V1?
1 user liked this post.
2025-06-14T06:53:00
permalink Post: 11901175
Speaking as a B787 Captain..... There is so much rubbish and stupid suggestion being written here.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
This aircraft was airborne for a grand total of 22 seconds, half of which was climbing to no more than 150' aal.
- No Flaps? Due to the setup of the ECL it is physically impossible to go down the runway without some sort of take-off flap set. The T/o config warning would have been singing it's head off. Despite assertions to the contrary I have seen no video clear enough to detect a lack of flaps.
- 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.
- Flaps up instead of gear? The B787 flaps are slow both in and out. Given that the 'Positive rate' call is not made the second the wheels leave the ground, a mis-selection of flaps up would not cause any loss of lift for at least 20 seconds, by which time they had already crashed. I believe the gear remained down not because of mis-selection but because of a major distraction on rotate.
Discounting the impossible, two hypotheses remain:
1. Invalid derate set through incorrect cross-checking. Trundling down the runway takes very little power to reach Vr. It is only when you rotate that you create more drag and discover that you do not have sufficient thrust vs. drag to sustain a climb. Or....
2. Put 200' as the altitude target in the FCU. Immediate ALT capture and all the power comes off. PF is still hand flying trying to increase pitch but is already way behind the aircraft.
It could be after this that Boeing are forced to review the B787 practice of exploring the very edges of the performance envelope.
1) The flap retraction would immediately result in progressive less lift, not only after full retraction . The time in the air could have been longer than your estimate, maybe enough time for full retraction
2) if 200 feet in MCP, why would that lead to a descent? Shouldn't that result in level flight?
3) wrong TOW / too low power setting sounds like a plausible event.Happened before. But with full power / TOGA set in the air ( which surely must have happened)I would expect at least a longer struggle rather than the constant descent. Just a gut feeling though, busdriver, no experience on 787. Maybe already in a power on stall. The only problem with this hypothesis is that it does not explain the gear down since there definitely was positive rate after rotation.
4) double engine failure too remote, no signs of flames etc. Forget it, agreed.
My guess remains inadvertant flaps retraction for what it's worth.
1 user liked this post.
2025-06-14T08:09:00
permalink Post: 11901235
hello guys,
I'm pilot but not on a heavy one, so I may have a naive question but eh..;depends on planes right ?
-let's imagine, the PM raise the flaps instead of gear (on 787). Is it really a big issue that could lead to a lose of 200/300 feet ?
I mean, you still have take of power ar at least climb power right ? sure you decrease the lift by raising the flaps (at constant speed though ) and lose some height, but the plane keep accelerating ,?
I'm pilot but not on a heavy one, so I may have a naive question but eh..;depends on planes right ?
-let's imagine, the PM raise the flaps instead of gear (on 787). Is it really a big issue that could lead to a lose of 200/300 feet ?
I mean, you still have take of power ar at least climb power right ? sure you decrease the lift by raising the flaps (at constant speed though ) and lose some height, but the plane keep accelerating ,?
2025-06-14T09:06:00
permalink Post: 11901283
IF, repeat IF, such a system was installed on that 787 it MIGHT have revealed a thrust problem before V1. ( and prevented the TUI BRS incident as well as EK at Melbourne)
So, after a lot of thought, an unexplained loss of thrust on BOTH engines must be in the frame. But why? What is common to BOTH except the autothrottle system, driving the thrust levers. Even then it is possible to manually firewall the thrust levers, at least one could on the 73,75, and 76.
So, a real mystery. I will await the Investigatirs conclusion now they have the FDR.
Last edited by RetiredBA/BY; 14th Jun 2025 at 13:27 .
2025-06-14T09:11:00
permalink Post: 11901290
Yes, we did acceleration checks, time to 100 knots, on the Valiant and, I believe, the Victor in the RAF. As well as brake drag, this proved engine performance was correct. I was surprised this was not done when I moved to civil jets. Many years ago I proposed a system called TOPIS. Take Off Performance Indicator System. Basically a bug driven around the ASI to show required and achieved speed.
IF, repeat IF, such a system was installed on that 787 it MIGHT have revealed a thrust problem before V1. ( and prevented the TUI BRS incident )
So, after a lot of thought, an unexplained loss of thrust on BOTH engines must be in the frame. But why? What is common to BOTH except the autothrottle system, driving the thrust levers. Even then it is possible to manually firewall the thrust levers, at least one could on the 73,75, and 76.
So, a real mystery. I will await the Investigatirs conclusion now they have the FDR.
IF, repeat IF, such a system was installed on that 787 it MIGHT have revealed a thrust problem before V1. ( and prevented the TUI BRS incident )
So, after a lot of thought, an unexplained loss of thrust on BOTH engines must be in the frame. But why? What is common to BOTH except the autothrottle system, driving the thrust levers. Even then it is possible to manually firewall the thrust levers, at least one could on the 73,75, and 76.
So, a real mystery. I will await the Investigatirs conclusion now they have the FDR.
2025-06-14T18:04:00
permalink Post: 11901699
There are a few comments along the lines of "it is incredibly unlikely that..." this is selection bias in reverse. Something incredibly unlikely
has
happened, and it's contained in this sample set.
To summarise some known facts about the TCMA system:
1) TCMA will shut down an engine if:
3) Since then the TCMA should have been updated/fixed (and indeed the software will have been updated by SB since the a/c was delivered, to detect a wider range of runaway conditions)
And speculation:
4) It may be possible - given the close timings - that a TCMA activation occurred as the a/c was leaving the ground, with kinetic energy and spool down time getting the a/c from the ground to its peak height
In the recent BA LGW incident the PF reduced thrust to idle at V1, then added thrust back, then committed to a RTO. I wonder if something similar could have occurred:
To summarise some known facts about the TCMA system:
1) TCMA will shut down an engine if:
- It believes via multiple redundant sensors indicate the aircraft is on the ground
- It detects engine power in excess of that set by the thrust levers - subject to a margin to account for engine performance variation - that is determined to be a runaway condition
3) Since then the TCMA should have been updated/fixed (and indeed the software will have been updated by SB since the a/c was delivered, to detect a wider range of runaway conditions)
And speculation:
4) It may be possible - given the close timings - that a TCMA activation occurred as the a/c was leaving the ground, with kinetic energy and spool down time getting the a/c from the ground to its peak height
In the recent BA LGW incident the PF reduced thrust to idle at V1, then added thrust back, then committed to a RTO. I wonder if something similar could have occurred:
- In error, PF reduces power to idle at a speed approaching V1
- Engines begin reducing power, but n1 reduces more slowly than the TCMA system is expecting (perhaps because the TCMA margin is calculated when the a/c is stationary, but at 170kt a turbofan will spool down more slowly due to the ram air / windmill effect)
- TCMA detects a runaway condition - while a/c is on the ground - and cuts off fuel via the relay circuit
- PF decides to commit to takeoff and rotates, not knowing that TCMA has already activated
- 10-15s after rotation, n1 has now dropped below minimums for electrical generation. Electrics fail, final transponder signal is sent, and RAT is deployed
6 users liked this post.
2025-06-14T19:36:00
permalink Post: 11901759
Was....
There is at least one other. RTO? Who was flying. At V1 the tension can be too much for an inexperienced FO who is flying. The mayday may have been spoken by the FO, after Captain tried to snatch controls back. It would explain an inexperienced left hand on the levers, and a non concert close of the throttle(s)
Unless....Captain was guarding the throttles, Initiated abort, and rethinks. Engines run, and run, and run.... They die of thirst.
Praying for an unbiased investigation and report ... Somebody needs to learn how to keep the lights on
Unless....Captain was guarding the throttles, Initiated abort, and rethinks. Engines run, and run, and run.... They die of thirst.
Praying for an unbiased investigation and report ... Somebody needs to learn how to keep the lights on
Last edited by BugBear; 14th Jun 2025 at 19:50 .
2025-06-14T20:52:00
permalink Post: 11901823
Each time I look at the video it strikes me as a flap retraction below clean climb speed. It looks as if the rate of pitch change and extreme nose high occurred gradually and at a rate which could be the pilot input for deteriorating climb rate based on the corresponding change in wing lift coefficient. I would assume also he was not instantly aware the flaps had been reselected to zero and if he became aware it was only a few seconds from impact. As far as my theory goes I would assume either the Captain commanded "FLAPS UP" erroneously or if he commanded "GEAR UP" the F/O just brain glitched without taking normal care in the cockpit with things like that. A normal procedure but with the same consequences of dealing with an engine fire after V1 IF you misidentify the switch or handle. Thats my opinion. As far as the crew experience it can be recognized the F/O was the weakest link in experience. Nothing new or different than that unless his training show deficiencies managing that cockpit.
2 users liked this post.
2025-06-14T21:04:00
permalink Post: 11901829
Each time I look at the video it strikes me as a flap retraction below clean climb speed. It looks as if the rate of pitch change and extreme nose high occurred gradually and at a rate which could be the pilot input for deteriorating climb rate based on the corresponding change in wing lift coefficient. I would assume also he was not instantly aware the flaps had been reselected to zero and if he became aware it was only a few seconds from impact. As far as my theory goes I would assume either the Captain commanded "FLAPS UP" erroneously or if he commanded "GEAR UP" the F/O just brain glitched without taking normal care in the cockpit with things like that. A normal procedure but with the same consequences of dealing with an engine fire after V1 IF you misidentify the switch or handle. Thats my opinion. As far as the crew experience it can be recognized the F/O was the weakest link in experience. Nothing new or different than that unless his training show deficiencies managing that cockpit.
The gear and flap controls are not easily confused in the 787. They look nothing alike and are not near each other.
2025-06-14T21:19:00
permalink Post: 11901847
Which side of V1
Also a newcomer here, but an experienced private pilot, Software Engineer with a degree in Aerospace Computer Science and former Head of Quality for Satellites and Interplanetary Missions. We have already seen bad software solutions and the results thereof in the 737 MAX accidents, which makes me wonder, if the TCMA can reach a state, where unintended engine shutdown is possible.
There is one system implemented in the 787, that has the authority to shut down the engines, based on software subsystem decision. Interestingly - according to the description in the patent below - the same TCMA software package determines the shutdown decision, in both redundant subsystems.
Excerpt from the Patent:
"Malfunctions in aircraft power plant thrust control systems can result in uncontrollable high engine power levels that are potentially hazardous or catastrophic for aircraft operation. A particularly hazardous situation is when a thrust control system failure results in one of the aircraft's engines continuing to operate at a high power condition and not responding to a throttle command to reduce power during takeoff, approach or landing. Typically, when this failure mode occurs, the actual thrust either increases to a significantly higher than commanded thrust and/or remains at a high level when the thrust levers are set for low thrust....
In one preferred embodiment the present invention is directed to a system and method for detecting and correcting a thrust control malfunction in an aircraft engine. The system includes an electronic engine control (EEC) unit that includes a first processing subsystem and a second processing subsystem, and a thrust control malfunction accommodation (TCMA) circuit included in the first processing subsystem and the second processing subsystem. Additionally, the system includes a TCMA software package executed by the first processing subsystem and the second processing subsystem, thereby providing redundant execution of the TCMA software package.
The method of the present invention compares the engine's actual power level with a threshold contour defined by the TCMA software package. When the TCMA software package determines that a thrust control malfunction has occurred, based on the engine's power level exceeding the threshold contour, the engine is shut down by the TCMA circuit.
The present invention is still further directed to an electronic engine control (EEC) unit configured to detect and correct an aircraft engine thrust control malfunction using an active-active functionality. The EEC includes a first processing subsystem for unilaterally monitoring engine operation and shutting down the engine when a thrust control malfunction occurs, and a second processing subsystem for unilaterally monitoring engine operation and shutting down the engine when a thrust control malfunction occurs."
Just my 20 cents
There is one system implemented in the 787, that has the authority to shut down the engines, based on software subsystem decision. Interestingly - according to the description in the patent below - the same TCMA software package determines the shutdown decision, in both redundant subsystems.
Excerpt from the Patent:
"Malfunctions in aircraft power plant thrust control systems can result in uncontrollable high engine power levels that are potentially hazardous or catastrophic for aircraft operation. A particularly hazardous situation is when a thrust control system failure results in one of the aircraft's engines continuing to operate at a high power condition and not responding to a throttle command to reduce power during takeoff, approach or landing. Typically, when this failure mode occurs, the actual thrust either increases to a significantly higher than commanded thrust and/or remains at a high level when the thrust levers are set for low thrust....
In one preferred embodiment the present invention is directed to a system and method for detecting and correcting a thrust control malfunction in an aircraft engine. The system includes an electronic engine control (EEC) unit that includes a first processing subsystem and a second processing subsystem, and a thrust control malfunction accommodation (TCMA) circuit included in the first processing subsystem and the second processing subsystem. Additionally, the system includes a TCMA software package executed by the first processing subsystem and the second processing subsystem, thereby providing redundant execution of the TCMA software package.
The method of the present invention compares the engine's actual power level with a threshold contour defined by the TCMA software package. When the TCMA software package determines that a thrust control malfunction has occurred, based on the engine's power level exceeding the threshold contour, the engine is shut down by the TCMA circuit.
The present invention is still further directed to an electronic engine control (EEC) unit configured to detect and correct an aircraft engine thrust control malfunction using an active-active functionality. The EEC includes a first processing subsystem for unilaterally monitoring engine operation and shutting down the engine when a thrust control malfunction occurs, and a second processing subsystem for unilaterally monitoring engine operation and shutting down the engine when a thrust control malfunction occurs."
Just my 20 cents
1 user liked this post.
2025-06-14T21:31:00
permalink Post: 11901857
TCMA
TCMA
Which side of V1 does TCMA lurk? If a pilot closes the throttles to abort, does the system allow it? After all, "too low thrust" is outside the contour....
Ya know, when every conceivable possibility (or close) has been de wormed, it"s usually something impossible, or too fearful...(Or dishonest, fraudulent, criminal ....etc ,? To include unnecessary, venal, and inappropriate)
Sledgehammer, flyswatter.... MCAS
Which side of V1 does TCMA lurk? If a pilot closes the throttles to abort, does the system allow it? After all, "too low thrust" is outside the contour....
Ya know, when every conceivable possibility (or close) has been de wormed, it"s usually something impossible, or too fearful...(Or dishonest, fraudulent, criminal ....etc ,? To include unnecessary, venal, and inappropriate)
Sledgehammer, flyswatter.... MCAS
Last edited by BugBear; 14th Jun 2025 at 21:41 .
2025-06-14T21:38:00
permalink Post: 11901864
I posited a potential TCMA sequence in a post timed 1804Z - speculative of course. Agree with others, it is difficult to contemplate and seems staggeringly unlikely.
1 user liked this post.