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.
2025-06-13T22:50:00
permalink Post: 11900977
I've been closely examining a video frame captured very early in the footage depicting the aircraft's final moments. In this particular frame, I believe the
left main landing gear (MLG) door is clearly visible in the open position
, while the
right MLG door appears closed
. Additionally, both
main gear bogies are noticeably tilted forward
\x97 a configuration that typically occurs at the initiation of the gear retraction sequence.
This combination strongly suggests that a gear retraction was commanded , but the sequence was interrupted and never completed . What\x92s particularly striking is the asymmetry \x97 the left door open, the right door closed \x97 which should not occur during normal operations and points toward a possible hydraulic failure scenario during retraction.
As many will know, on the Boeing 787-8, each main gear door is hydraulically actuated and powered by its respective side\x92s hydraulic system \x97 the left gear door by the left hydraulic system , and the right by the right . This leads me to propose the following hypothesis:
Further supporting this theory are:
In the meantime, my thoughts are very much with all those affected by this heartbreaking event.
( NOTE: Unfortunately this is my first post here. I wanted to upload the frame for all to see but the forum is restricting me from doing this until I reach 8 posts. I can't link to it via a URL either. I studied a frame from the very start of the video, just as the full aircraft enters view and expanded it by 400% allowing me to see the position of the MLG doors).
This combination strongly suggests that a gear retraction was commanded , but the sequence was interrupted and never completed . What\x92s particularly striking is the asymmetry \x97 the left door open, the right door closed \x97 which should not occur during normal operations and points toward a possible hydraulic failure scenario during retraction.
As many will know, on the Boeing 787-8, each main gear door is hydraulically actuated and powered by its respective side\x92s hydraulic system \x97 the left gear door by the left hydraulic system , and the right by the right . This leads me to propose the following hypothesis:
-
Shortly after rotation, with a positive rate of climb established, the
flight crew commands gear up
.
-
The
gear retraction sequence initiates
; the
main gear bogies tilt forward
, consistent with the start of retraction.
-
The right engine fails first
, resulting in a
loss of right hydraulic system pressure
. Consequently, the
right MLG door does not open
.
-
The
left MLG door, still powered by the left hydraulic system, opens
.
-
Moments later, the left engine also fails
, leading to
loss of the left hydraulic system
. With the door now open but no remaining hydraulic pressure,
the left main gear remains extended and the door remains open
.
-
The
ram air turbine (RAT) deploys
, consistent with total engine and electrical power loss.
-
With the
loss of thrust from both engines
, the aircraft loses lift and enters an unrecoverable descent, tragically ending in impact.
Further supporting this theory are:
-
Eyewitness reports of a loud bang
, possibly indicating an engine failure.
-
A
mayday call
reportedly made by the crew.
-
The
audible presence of the RAT
in the video, suggesting a complete loss of engine-driven electrical and hydraulic systems.
-
The
noticeable absence of typical engine noise
, supporting the hypothesis of dual engine failure.
In the meantime, my thoughts are very much with all those affected by this heartbreaking event.
( NOTE: Unfortunately this is my first post here. I wanted to upload the frame for all to see but the forum is restricting me from doing this until I reach 8 posts. I can't link to it via a URL either. I studied a frame from the very start of the video, just as the full aircraft enters view and expanded it by 400% allowing me to see the position of the MLG doors).
2 users liked this post.
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.
2025-06-13T23:16:00
permalink Post: 11900989
I have no knowledge about 787, but every landing gear system I\x92ve worked with did not sequence Left and Right MLG to retract and extend with each other. In fact it is typical for left and right side to move at slightly different speed due to different friction etc. Retraction assymmetry is probably not a clue to this mystery.
The 787 landing gear is operated by the centre hydraulic system's two electric pumps.
I have no idea why they have posted such nonsense.
1 user liked this post.
2025-06-13T23:40:00
permalink Post: 11901003
I\x92m not qualified on the B787, on the G650ER that I fly the flight controls can be powered by the batteries in the EBHA\x92s, does the Boeing need the RAT for hydraulic power if the engines are not providing electrical power?
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.
2025-06-13T23:58:00
permalink Post: 11901012
The B787 is a way way different and much more complex and sophisticated plane than your Gulfie. The B787's two outermost (left & right) hydraulic systems are primarily driven by the engines, mechanically driving the hydraulic pumps. The center hydraulics are primarily electrically driven, and power the main flight controls, amongst other things like the gear. The left and right ones power the main flight controls as well, some of the less important flight control surfaces like spoilers and thrust reversers -- pardon me for not having the exact list of things. They also have a backup/supplementary electric pump each. Each of the two main engines has redundancy for the power plant a.k.a. VFSG (and motor-driven pump?) in its own right as well. All three hydraulic systems work together in a redundant fashion when it comes to the primary flight controls. The RAT can provide both electrical and mechanical sources of hydraulic support, if I'm not mistaken. The flight instrument and information systems can also be powered from two backup batteries, the APU power plant itself, and/or the RAT.
2 users liked this post.
2025-06-14T00:22:00
permalink Post: 11901021
The B787 is a way way different and much more complex and sophisticated plane than your Gulfie. The B787's two outermost (left & right) hydraulic systems are primarily driven by the engines, mechanically driving the hydraulic pumps. The center hydraulics are primarily electrically driven, and power the main flight controls. The left and right ones power the main flight controls as well, some of the less important flight control surfaces like spoilers and thrust reversers -- pardon me for not having the exact list of things. They also have a backup/supplementary electric pump each. Each of the two main engines has redundancy for the power plant a.k.a. VFSG (and motor-driven pump?) in its own right as well. All three hydraulic systems work together in a redundant fashion when it comes to the primary flight controls. The RAT can provide both electrical and mechanical sources of hydraulic support, if I'm not mistaken. The flight instrument and information systems can also be powered from two backup batteries, the APU power plant itself, and/or the RAT.
1 user liked this post.
2025-06-14T02:16:00
permalink Post: 11901080
As many will know, on the Boeing 787-8,
each main gear door is hydraulically actuated and powered by its respective side’s hydraulic system
— the
left gear door by the left hydraulic system
, and the
right by the right
. This leads me to propose the following hypothesis:
The Centre Hydraulic system is powered by two Electric Motor Pumps.
Obviously, the two Centre pumps are ultimately powered by electrical power from the VFSGs on the engines and/or the APU.
Note: the RAT will not (and could not!) supply hydraulic power to the gear system.
1 user liked this post.
2025-06-14T03:05:00
permalink Post: 11901101
Miscellaneous comments:
I have seen in manuals for other airliners that because the bogie tilt is by a hydraulic actuator, gravity deploying the gear means the gear doesn't tilt to landing position.
With the loss of centre-system pressure*, would you expect the bogies to tilt naturally? I.e. spring pressure holds the gear in the stowed tilt, a hydraulic cylinder pushes the gear to the landing tilt. No pressure means the gear returns to the 'stowed' tilt.
The tilt actuator is designed to be overridden when the bogie hits the ground, so perhaps it has some kind of intentional bypass and doesn't stay in place without continually applied hydraulic pressure.
If so, that would also point towards total loss of electrics and no attempt to raise the gear.
* 787 centre system is powered by two electric pumps, plus the RAT. The RAT hydraulic pump only powers flight controls, not the landing gear.
Electric loss:
Surely even total AC power loss shouldn't result in engine loss, even if the RAT doesn't come online. The FADECs have their own alternators, bare minimum flight control computers and actuators are available on battery (though probably result in some equivalent of Direct Law), and boost pumps are unnecessary at low altitude. Left/right EDPs will remain active if the engines are running at any serious speed; providing flight controls.
Poor crew reaction to ending up in direct law is possible but it's hard to see the electrical issues as a cause, not a symptom.
Anti-terrorism squad looks to be doing an excellent job (/s) and recovered a convenience-store-grade CCTV recorder, probably from somewhere on the campus it crashed into:
https://economictimes.indiatimes.com.../121823103.cms
With the loss of centre-system pressure*, would you expect the bogies to tilt naturally? I.e. spring pressure holds the gear in the stowed tilt, a hydraulic cylinder pushes the gear to the landing tilt. No pressure means the gear returns to the 'stowed' tilt.
The tilt actuator is designed to be overridden when the bogie hits the ground, so perhaps it has some kind of intentional bypass and doesn't stay in place without continually applied hydraulic pressure.
If so, that would also point towards total loss of electrics and no attempt to raise the gear.
* 787 centre system is powered by two electric pumps, plus the RAT. The RAT hydraulic pump only powers flight controls, not the landing gear.
Electric loss:
Surely even total AC power loss shouldn't result in engine loss, even if the RAT doesn't come online. The FADECs have their own alternators, bare minimum flight control computers and actuators are available on battery (though probably result in some equivalent of Direct Law), and boost pumps are unnecessary at low altitude. Left/right EDPs will remain active if the engines are running at any serious speed; providing flight controls.
Poor crew reaction to ending up in direct law is possible but it's hard to see the electrical issues as a cause, not a symptom.
https://economictimes.indiatimes.com.../121823103.cms
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.
2025-06-14T07:18:00
permalink Post: 11901188
A summary of the more certain things we know about the accident so far:
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction. What exactly caused the engine/electrical issues remains speculative. An action slip mistaking flaps for gear seems much less likely as due to the above, the correct selection was probably made.
From the videos of the last moments, there is strong evidence that the RAT was deployed, which has a very short list of possible triggers. The sole eye witness from inside describes power issues which lends credence.
Taken together, it seems that there was an event (or events) shortly after rotation that compromised both engines and the electrical system. There is no evidence yet of birdstrikes and continued engine operation *should* not be affected by the aircraft electrical system as they are independently/internally powered, so logic would have the engines failing first leading to a cascade of other problems. Something that affects all engines pretty much simultaneously is a rare beast but it has happened in the past; outside of a deliberate selection of the fuel and/or fire switches for both power plants there is fuel contamination, FOD and not much else. Its seems at least one FDR has been recovered so depending on where they take it for read-out, we should get some initial facts fairly shortly.
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction. What exactly caused the engine/electrical issues remains speculative. An action slip mistaking flaps for gear seems much less likely as due to the above, the correct selection was probably made.
From the videos of the last moments, there is strong evidence that the RAT was deployed, which has a very short list of possible triggers. The sole eye witness from inside describes power issues which lends credence.
Taken together, it seems that there was an event (or events) shortly after rotation that compromised both engines and the electrical system. There is no evidence yet of birdstrikes and continued engine operation *should* not be affected by the aircraft electrical system as they are independently/internally powered, so logic would have the engines failing first leading to a cascade of other problems. Something that affects all engines pretty much simultaneously is a rare beast but it has happened in the past; outside of a deliberate selection of the fuel and/or fire switches for both power plants there is fuel contamination, FOD and not much else. Its seems at least one FDR has been recovered so depending on where they take it for read-out, we should get some initial facts fairly shortly.
14 users liked this post.
2025-06-14T07:22:00
permalink Post: 11901193
(I screwed up earlier and had a 767 image here...)
Taken together, it seems that there was an event (or events) shortly after rotation that compromised both engines and the electrical system.
Compromising both engines inherently compromises the electrical system: dropping below idle N2 (plus some safety margin) disconnects generators.
Last edited by Someone Somewhere; 14th Jun 2025 at 17:57 .
2 users liked this post.
2025-06-14T08:30:00
permalink Post: 11901251
A summary of the more certain things we know about the accident so far:
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction. What exactly caused the engine/electrical issues remains speculative. An action slip mistaking flaps for gear seems much less likely as due to the above, the correct selection was probably made.
From the videos of the last moments, there is strong evidence that the RAT was deployed, which has a very short list of possible triggers. The sole eye witness from inside describes power issues which lends credence.
Taken together, it seems that there was an event (or events) shortly after rotation that compromised both engines and the electrical system. There is no evidence yet of birdstrikes and continued engine operation *should* not be affected by the aircraft electrical system as they are independently/internally powered, so logic would have the engines failing first leading to a cascade of other problems. Something that affects all engines pretty much simultaneously is a rare beast but it has happened in the past; outside of a deliberate selection of the fuel and/or fire switches for both power plants there is fuel contamination, FOD and not much else. Its seems at least one FDR has been recovered so depending on where they take it for read-out, we should get some initial facts fairly shortly.
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction. What exactly caused the engine/electrical issues remains speculative. An action slip mistaking flaps for gear seems much less likely as due to the above, the correct selection was probably made.
From the videos of the last moments, there is strong evidence that the RAT was deployed, which has a very short list of possible triggers. The sole eye witness from inside describes power issues which lends credence.
Taken together, it seems that there was an event (or events) shortly after rotation that compromised both engines and the electrical system. There is no evidence yet of birdstrikes and continued engine operation *should* not be affected by the aircraft electrical system as they are independently/internally powered, so logic would have the engines failing first leading to a cascade of other problems. Something that affects all engines pretty much simultaneously is a rare beast but it has happened in the past; outside of a deliberate selection of the fuel and/or fire switches for both power plants there is fuel contamination, FOD and not much else. Its seems at least one FDR has been recovered so depending on where they take it for read-out, we should get some initial facts fairly shortly.
This indeed is the best summary till now
3 users liked this post.
2025-06-14T09:23:00
permalink Post: 11901300
Double power loss causality
A summary of the more certain things we know about the accident so far:
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction .
The takeoff run was from the full length and appeared normal, even after comparing with the same flight on previous days. This very much reduces the likelihood of it being a performance issue, e.g. wrong flaps, derate, ZFW/TOW, etc.
Shortly after takeoff, the gear started retracting but stopped in an early intermediate position. At the same time the aircraft climb rate dropped off, then it started a shallow descent. This is consistent with a loss of electrical power causing a loss of hydraulic pressure and total engine thrust from both engines reducing below that generated by one engine at the takeoff setting. The position reporting also went offline at that moment, indicating that it was likely load shed due to an electrical malfunction .
I personally think this is a good summary of what we can ascertain at this point from the evidence we have.
I am not a 787 driver by any means but with a fair bit of aviation experience. I would be interested in any thoughts on this suggestion regarding loss of thrust:
If we take it as a reasonable assumption as above that it is almost simultaneous loss of significant thrust, and for the good reasons already discussed, it is pretty unlikely that from what we can see/analyse, that the cause of this would be bird strike (expect to see some signs on video if it's significant enough to cause double engine failure) nor fuel contamination (reasons as above re: likelihood, other ac affected and simultaneous nature). TCMA I don't know enough about but it seems that the sensor redundancy/logic protection is so high it would not be the sole cause.
On this basis, should we perhaps consider the causality of a total electrics failure of some kind first, leading to deployment of the RAT, gear retraction cease etc. Clearly the independent FADEC power generation systems would mean this doesn't on its own prevent thrust control of the engines but could we then be looking at cascading faults (possibly exacerbated by latent faults below the MEL/defect threshold) that contribute to dual power loss and sensor/system issues in throttle response not resulting in FADEC commands to the engines to increase thrust. So even at that point 'firewalling' the throttles could tragically not recover the situation?
Very happy to be corrected by those with much more experience and understanding of big jets operations and systems!
2025-06-14T11:49:00
permalink Post: 11901397
I think they meant the retraction had "commenced". A previous post said the bogeys on the -8 tip forward, then the doors open. In the video, the bogeys are tipped forward but the doors remain closed.
Plane crash near Ahmedabad..
Plane crash near Ahmedabad..
1 user liked this post.
2025-06-14T12:24:00
permalink Post: 11901432
The B787 is a way way different and much more complex and sophisticated plane than your Gulfie. The B787's two outermost (left & right) hydraulic systems are primarily driven by the engines, mechanically driving the hydraulic pumps. The center hydraulics are primarily electrically driven, and power the main flight controls, amongst other things like the gear. The left and right ones power the main flight controls as well, some of the less important flight control surfaces like spoilers and thrust reversers -- pardon me for not having the exact list of things. They also have a backup/supplementary electric pump each. Each of the two main engines has redundancy for the power plant a.k.a. VFSG (and motor-driven pump?) in its own right as well. All three hydraulic systems work together in a redundant fashion when it comes to the primary flight controls. The RAT can provide both electrical and mechanical sources of hydraulic support, if I'm not mistaken. The flight instrument and information systems can also be powered from two backup batteries, the APU power plant itself, and/or the RAT.
The Global Express has 4 engine driven generators, one APU generator, one RAT generator that provide AC and DC power to the aircraft's systems. On the hydraulic side, the aircraft has 3 fully independent and redundant hydraulic systems which power all flight control surfaces the exception being, the slats and flaps are AC power driven and are available even with only the RAT providing power. The 3 hydraulic systems are powered from each engine backed up by 2 EDPs (system 1 and 2) and system 3 is powered by 2 EDPs only. The RAT powers system 3 via one of its EDPs. In the event of a dual engine failure the RAT would deploy automatically and power the AC essential plus DC essential busses and one EDP on system 3. The APU is available to you up to FL450 and will supply full AC power but bleed air only up to FL300.
5 users liked this post.
2025-06-14T12:48:00
permalink Post: 11901455
Sorry but before you make a statement like this, you better read up on the "complexity and sophistication" of the latest business jets like the Gulfstreams and Global Express.
The Global Express has 4 engine driven generators, one APU generator, one RAT generator that provide AC and DC power to the aircraft's systems. On the hydraulic side, the aircraft has 3 fully independent and redundant hydraulic systems which power all flight control surfaces the exception being, the slats and flaps are AC power driven and are available even with only the RAT providing power. The 3 hydraulic systems are powered from each engine backed up by 2 EDPs (system 1 and 2) and system 3 is powered by 2 EDPs only. The RAT powers system 3 via one of its EDPs. In the event of a dual engine failure the RAT would deploy automatically and power the AC essential plus DC essential busses and one EDP on system 3. The APU is available to you up to FL450 and will supply full AC power but bleed air only up to FL300.
The Global Express has 4 engine driven generators, one APU generator, one RAT generator that provide AC and DC power to the aircraft's systems. On the hydraulic side, the aircraft has 3 fully independent and redundant hydraulic systems which power all flight control surfaces the exception being, the slats and flaps are AC power driven and are available even with only the RAT providing power. The 3 hydraulic systems are powered from each engine backed up by 2 EDPs (system 1 and 2) and system 3 is powered by 2 EDPs only. The RAT powers system 3 via one of its EDPs. In the event of a dual engine failure the RAT would deploy automatically and power the AC essential plus DC essential busses and one EDP on system 3. The APU is available to you up to FL450 and will supply full AC power but bleed air only up to FL300.
Elsewhere, there is a picture of the tail wreckage showing what looks likethe APU door partially open. The panel is otherwise undamaged indicating not caused by post-impact. I’ll try to poach it
its here, but wrong file extension on the photo
https://www.nytimes.com/interactive/...smid=url-share
Last edited by galaxy flyer; 14th Jun 2025 at 13:52 .