Posts about: "RAT (All)" [Posts: 607 Pages: 31]

overstress
2025-06-13T20:19:00
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Post: 11900867
Originally Posted by bobbytables
I wouldn\x92t say that it changes anything at all. Pax statements are all over the place with these kinds of events. If there were more survivors there would be a few who said they saw a fireball outside, etc.
Yet credence is given here to his recollection of a bang and green lights etc, yet his comments about THRUST increasing are ignored by the RAT theorists\x85

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ams6110
2025-06-13T20:23:00
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Post: 11900870
Originally Posted by overstress
Yet credence is given here to his recollection of a bang and green lights etc, yet his comments about THRUST increasing are ignored by the RAT theorists\x85
In fairness, recalling a "green light" is a pretty specific thing. A "sensation of thrust" from a seated passenger who may not even be an experienced flyer could be describing any feeling of movement or the illusion of same.

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bobbytables
2025-06-13T20:24:00
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Post: 11900871
Originally Posted by overstress
Yet credence is given here to his recollection of a bang and green lights etc, yet his comments about THRUST increasing are ignored by the RAT theorists\x85
I don\x92t give credence to any of his recollections. I do find the recorded sound of the RAT quite compelling after watching some other videos of a deployed RAT and hearing from the chap who hears them fly over while testing them every day. The photo of the section of wing in the wreckage with flaps still extended also puts paid to the other main theory, in my mind.

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Del Prado
2025-06-13T20:31:00
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Post: 11900874
Originally Posted by Pip_Pip

The only comments I would add are:-

- It's a stretch to say the RAT is seen or heard "conclusively". Doubts have been expressed about the video quality and there are dissenting views regarding the audio. If a few more people were able to wade in on the audio point in particular, this could be very beneficial in moving the discussion forward because the presence or otherwise of the RAT is significant to several competing theories.

- On the subject of audio, I am surprised there has not been more discussion regarding engine noise. In the primary eye witness video the (alleged) RAT can be heard distinctly, as can the sounds of distant impact. If the engines were working

- Gear bogies: I'm not sure a consensus has yet been reached regarding the angle of the bogies. (I am not personally qualified to comment on this - I am purely saying I don't see a clear consensus just yet among those who are)

- Mayday call: I don't recall seeing a confirmed source for the widely reported mayday. Others have brought this up in the thread but nobody appears to be able to confirm one way or the other. If accurate, its contents are informative. Am I right to presume that you have left it out of your summary due to a lack of confirmation?
Thanks for the response. All great points you raise.

I simply forgot to mention the Mayday. I think there are enough sources to suggest one was made but I\x92m slightly wary of its content.
The recording and rebroadcast of RT exchanges is illegal in India as it is in the U.K. so we can\x92t be sure until its official release.

Gear bogies - This was also mentioned by Juan Browne/Blancolirio as something to focus on, that\x92s probably what swayed me on this.

I was initially in the gear up/flaps up camp but I\x92ve been impressed by the testimonies of others here, particularly by the poster who\x92s heard hundreds of these overhead and the several videos shared for comparison.

As you say, hopefully we can put most of these topics to bed now (unless there is contradictory new evidence) and focus instead on where Occam\x92s razor points us.

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neila83
2025-06-13T20:50:00
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Post: 11900886
Originally Posted by go-around flap 15
We're all shouting each other down with two main different theories on why the aircraft lost lift so shortly after takeoff.

1) Incorrect flap retraction causing the aircraft to lose lift and unable to recover the energy in time. (Not unheard of and plenty of reports where this has happened - albeit usually not to a crash).

2) Loss of engine thrust backed up two potential pieces of evidence that back up the RAT was deployed (apparent RAT sound, potential RAT seen on low res video).

It is impossible to know which of these is the case. Considering this summary of memory items is there the potential for a combination of both theories to have taken place?

Inadvertant flap retraction by PNF leading the PF to sense a sink and loss of lift. Pushes the thrust levers forward to the firewall and still the aircraft sinks. PF looking through the HUD and so very much 'outside focused' and doesn't realise that PNF has instead moved the flaps. PF defaults to memory items for loss of thrust on both engines before PNF can realise or communicate to PF what they've done, start switches are cut off which drops the RAT and from that point they're only heading one way. This would satisfy the strongly held belief that the RAT was extended, whilst also following the more likely initial cause of an action slip by PNF starting the sequence, rather than a dual engine failure.
Why the need to make the two theories fit in such a convoluted manner? Inadvertent flap retraction was theorised because people assumed that was most likely to have caused the loss of lift - hardly anyone believed dual engine failure was possible. Now we know that the loss of lift was indeed almost certainly caused by a loss of engine power, why all these awkward attempts to reverse engineer it to still fit the flap retraction theory? People need to realise they are only trying to make the flap retraction theory fit because of cognitive biases. If we had all been told immediately, there was dual power loss and the RAT deployed, no-one would even be considering flaps. Its confirmation bias of past assumptions, that's all.

As has been said many times as well, the landing gear retraction process appears to start as the bogies tilt, and then suddenly stops. Which rather suggests they did pull the gear lever. Based on the videos and the amount of speed the plane lost in the very brief sequence ovents, I'd say that the plane lost power a lot earlier than it would have in your theory.

Last edited by neila83; 13th Jun 2025 at 21:03 .

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nachtmusak
2025-06-13T21:03:00
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Post: 11900901
Originally Posted by ams6110
In fairness, recalling a "green light" is a pretty specific thing. A "sensation of thrust" from a seated passenger who may not even be an experienced flyer could be describing any feeling of movement or the illusion of same.
In the spirit of fairness there is another sensation that can be interpreted as "increased thrust" that a passenger is equally if not more likely to be talking about : a change in [perceived] engine noise level and/or quality.

Personally I don't hear much of the engines as the plane moves away from the cameraperson in the phone video, while the sound of impact is clearly discernible. If anyone can hear the engines well enough to tell if there is a significant change in their tone or volume, that would be valuable info, I think. Alternatively whatever increase in noise was heard started before the recording starts. In that case I suppose the "RAT theorists" would say it was the droning of the now-deployed RAT, with the assumption that it would be audible from inside the cabin (things like flap and landing gear actuation certainly are, so that isn't all that far-fetched). On the other hand, the "flap theorists" would probably say it was the crew firewalling the thrust levers in response to the inability to climb, which isn't far-fetched either.

Either way we will know soon enough what actions the pilots did or didn't take, since the various flight recorders should be found fairly easily in good condition.
neila83
2025-06-13T21:31:00
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Post: 11900927
Originally Posted by nachtmusak
In the spirit of fairness there is another sensation that can be interpreted as "increased thrust" that a passenger is equally if not more likely to be talking about : a change in [perceived] engine noise level and/or quality.

Personally I don't hear much of the engines as the plane moves away from the cameraperson in the phone video, while the sound of impact is clearly discernible. If anyone can hear the engines well enough to tell if there is a significant change in their tone or volume, that would be valuable info, I think. Alternatively whatever increase in noise was heard started before the recording starts. In that case I suppose the "RAT theorists" would say it was the droning of the now-deployed RAT, with the assumption that it would be audible from inside the cabin (things like flap and landing gear actuation certainly are, so that isn't all that far-fetched). On the other hand, the "flap theorists" would probably say it was the crew firewalling the thrust levers in response to the inability to climb, which isn't far-fetched either.

Either way we will know soon enough what actions the pilots did or didn't take, since the various flight recorders should be found fairly easily in good condition.
Good summary, I'd just say the thrust levers definitely weren't firewalled. The plane lost a huge amount of speed by impact. This single fact should be enough to end the flap retraction theory. It lost a huge amount of speed while descending - now what might cause that? The gear also begin the retraction process (bogies tilting). The obsession with flaps when there isn't a single piece of evidence for it is very odd. (not suggesting you are guilty of it btw).

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Flaperon777
2025-06-13T21:51:00
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Post: 11900945
Most Plausible \x85

In my opinion ( and we all know the cliche about opinions ), there are only two plausible explanations.
1. Dual engine failure/damage due to multiple bird strikes somewhere immediately after V2 and liftoff.
Given the suddenness of the situation the gear could well have been overlooked by the PM who would be checking out the engine parameters only at this point in time. Flaps were in 5 position. No doubt about that.
Take off thrust used was for Optimum thrust
( meaning minimum thrust for take off given runway and environmental conditions ). That accounts for the full runway length being used. This is policy. That means minimum thrust used for take off to meet 2nd segment climb gradient at almost MTOW.
Loss of total thrust, RAT may or may not have deployed. At 650, AMSL no chance of any relight or turn back. Rest is history.
This also corresponds to the thud heard by the survivor about 30 seconds after takeoff.

2. Loss of thrust in only one engine and degraded performance in the other. Again, due to bird strike. Thereby not allowing even level flight.
Gear staying down could have been overlooked by mistake OR left down intentionally forseeing an impending ground contact by PIC and trying to minimize damage to his airplane.
Eitherways it added to additional drag and if anything, only accelerated the process of ground contact.
Given the above conditions safe flight would have been close to impossible. If not completely impossible. He neither had the airspeed not the altitude to make a 180 or even look for a safer place to put her down.
Refer the last Concorde flight/crash.

A very very sad day for aviation indeed \x85 🙏

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fdr
2025-06-13T21:54:00
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Post: 11900950
The Daily Telegraph has apparently put out a photo that is of the rear view of the aircraft, showing the TE flaps have a visible gap between the flap element and the wing, that is, the flaps are extended. If they were not, you get to see nothing. Int he gap, you can clearly see the fan exit of both engines.... ergo, the TE flaps are deployed. This same article then highlights this and exclaims that the flaps were retracted.

Is it safe to assume that the education standard of writers and editors of UK papers has been depleted somewhat?

Such comments are inflammatory to those that have lost family in this tragedy, and directly impugn the flight crew, and are factually, grossly wrong. This isn't just sloppy journalism, it is defamatory to those that cannot speak in their own defence. Sorry Mods, but someone needs to stand up for those that cannot against offensive drivel that passes for informed media commentary.

Here is a photo of the aircraft at the point that some numpties have stated the flaps are not employed. Apparently the authors should visit spec savers, or get a guide dog at least. At least, they get great blue coloured parking. In the same image, the RAT is observable.

The comments that are floated that some experts suggest that the crew may have not been able to get the gear up and may have retracted the flaps shows an utter lack of understanding of the certification basis of our aircraft. The flaps are out at a relevant TO flap extension setting for the conditions.

The same bastion of British broadsheets shows an image that is already on this thread, of a takeoff from mid field, while at the same time showing a still of the NE corner video near the RVR gauge east of the PAPI at the N end of the runway. One can only conclude that there is a dearth of good loo paper in the UK, and this standard of rigorous investigative reporting can be best applied to ones soft spots for personal hygiene. take 5 minutes out and do an triangulation from the point of observation, and surprise, the aircraft lifts off abeam the closed high speed taxiway. Not at the end of the runway, 1250 meters north of the DER. Taking ADSB data and not running a validation of it is mentally lazy and leads to hurtful assumptions that taking a slight amount of reasonable due care would have avoided.

rude letter follows...







https://www.telegraph.co.uk/news/202...a-plane-crash/


This is interesting enough without dealing with the media who show once again the mental acuity and sharp insight of a bowling ball.

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neila83
2025-06-13T21:58:00
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Post: 11900955
Originally Posted by SpGo
Retracting the flaps would put them at the back of the power curve where drag increases with decreasing speed, causing the speed to reduce further!
The trouble seems to start at the exact moment the gear should have been raised, putting the flaps up, iso the gear, would cause the kind of loss of lift you see in the video. From there on, being at the back of the power curve, only firewalling the thrust levers and extending the flaps again could have saved them.
Yes indeed, the moment they pulled the gear lever, as we see the gear begin the retraction process, and then suddenly stop. Almost as if they suddenly lost power.

We can see the landing gear retraction process begin. We see the bogies tilted in the second video. We can hear the RAT. We can see the RAT. We can see the flaps extended in the video and at the crash site. There isn't actually a single piece of evidence the flaps were raised, it's just a conclusion people jumped too before evidence began to emerge.

The crazy thing is, when the report comes out and there is no mention of flaps none of the people who have been pushing the flap theory will self reflect or learn anything. They'll think those of us who didn't buy into it were just lucky, rather than it being down to use of fairly simple critical thinking.

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Right Way Up
2025-06-13T22:08:00
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Post: 11900961
Originally Posted by neila83
Yes indeed, the moment they pulled the gear lever, as we see the gear begin the retraction process, and then suddenly stop. Almost as if they suddenly lost power.

We can see the landing gear retraction process begin. We see the bogies tilted in the second video. We can hear the RAT. We can see the RAT. We can see the flaps extended in the video and at the crash site. There isn't actually a single piece of evidence the flaps were raised, it's just a conclusion people jumped too before evidence began to emerge.

The crazy thing is, when the report comes out and there is no mention of flaps none of the people who have been pushing the flap theory will self reflect or learn anything. They'll think those of us who didn't buy into it were just lucky, rather than it being down to use of fairly simple critical thinking.
I think you need to temper your tone This is a discussion about possibilities and quite honestly nothing would surprise me. There is no "winning" result here. Just hopefully answers which will help safety in the future.

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fdr
2025-06-13T22:13:00
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Post: 11900962
Originally Posted by Turkey Brain
At this stage, at least two scenarios seem highly plausible:

1. Technical issue

Airliners rely on air/ground logic , which is fundamental to how systems operate.

There have been numerous crashes and serious incidents linked to this logic functioning incorrectly.

Some engineering tests require the air/ground switch to be set in a particular mode. If it's inadvertently left in engineering mode—or if the system misinterprets the mode—this can cause significant problems.
  • On the ground , if the aircraft is incorrectly in air mode , some systems may be unavailable—such as wheel brakes, reverse thrust, or ground spoilers.
  • In the air , if the aircraft is mistakenly in ground mode , flaps might auto-retract, and various layers of system protection may be disabled.
In the case of the ANA 787, it appears the engine shutdown occurred during the landing roll, possibly when the TCMA system activated.

2. Pilot misselection of fuel control switches to cutoff

This is still a very real possibility. If it occurred, the pilot responsible may not have done it consciously—his mindset could have been in a different mode.

There’s precedent: an A320 pilot once inadvertently shut down both engines over Paris. Fortunately, the crew managed to restart them. Afterward, the pilot reportedly couldn’t explain his actions.

If something similar happened here, then when the pilots realized the engines had stopped producing thrust, pushing the levers forward would have had no effect. It’s easy to overlook that the fuel switches are in the wrong position—they're far from the normal scan pattern. And with the ground rushing up, the view outside would’ve been far more commanding.

Speaking personally, when I shut down engines at the end of a flight, I consciously force myself to operate each fuel switch independently and with full attention. I avoid building muscle memory that might lead to switching off both engines in a fast, well-practiced habit.

If this is a technical issue, I assume we’ll know soon enough.
On item 1, the TCMA issue should have been fixed, it does fit the sort of issue that occurred here. TDRACER can talk to that, and has done in 2019 and again in post 792. As to flap auto retraction, the B787 like all Boeings has a gated flap lever, and the flaps are only able to move independent of the lever by flap load relief. That would not have caused a loss of thrust, and in this case it is evident that the event is a thrust loss not a CL loss.

On item 2, the video shows no asymmetry at any time, so there is only a symmetric failure of the engines possible. Back on a B747 classic, you could chop all 4 engines at the same time with one hand, on a B737, also, not so much on a B777 or B787. I would doubt that anyone used two hands to cut the fuel at screen height. Note, there was a B744 that lost one engine in cruise when a clip board fell off the coaming. Didn't happen twice, and it only happened to one engine.


Originally Posted by neila83
Yes indeed, the moment they pulled the gear lever, as we see the gear begin the retraction process, and then suddenly stop. Almost as if they suddenly lost power.

We can see the landing gear retraction process begin. We see the bogies tilted in the second video. We can hear the RAT. We can see the RAT. We can see the flaps extended in the video and at the crash site. There isn't actually a single piece of evidence the flaps were raised, it's just a conclusion people jumped too before evidence began to emerge.

The crazy thing is, when the report comes out and there is no mention of flaps none of the people who have been pushing the flap theory will self reflect or learn anything. They'll think those of us who didn't buy into it were just lucky, rather than it being down to use of fairly simple critical thinking.
​​​​​
Neila83 is correct, the gear tilt pre retraction is rear wheels low, and at the commencement of the selection of the retraction cycle (generally), the first thing that happens is the inboard MLG doors start to open below the wheel well and then the bogie is driven to front wheels low. (There is also an option that the inboard gear doors start to open early as a result of WOW sensing to improve the SSL climb limit). [my bad, for the B788 Capt Bloggs informs us the gear door sequence is after the tilt, not before, the B789 has the before tilt, the option for the door open at rotate is separate]

The inboard doors do not appear to have opened in this case, yet, the gear is forward wheels down. This appears to be out of sequence. TD may have better knowledge on the options that exist with the B788, but this is not looking good at this time.

There is enough in the way of anomalies here to end up with regulatory action, and airlines themselves should/will be starting to pore over their systems and decide if they are comfortable with the airworthiness of the aircraft at this moment. A latent single point of failure is not a comfortable place to be. Inhibiting TCMA might be a good interim option, that system could have been negated by having the ATR ARM switches....(Both)... ARM deferred to the before takeoff checks. The EAFR recovery should result in action within the next 24-48 hours. Boeing needs to be getting their tiger teams warmed up, they can ill afford to have a latent system fault discovered that is not immediately responded to, and the general corporate response of "blame the pilots" is not likely to win any future orders.

I think we are about to have some really busy days for the OEM.


Originally Posted by Right Way Up
I think you need to temper your tone This is a discussion about possibilities and quite honestly nothing would surprise me. There is no "winning" result here. Just hopefully answers which will help safety in the future.
Not sure that Neila83 is that far off the mark at all.

Last edited by fdr; 14th Jun 2025 at 01:21 . Reason: corrected for B788 by Capt Bloggs!

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Magplug
2025-06-13T22:13:00
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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.

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Laxx
2025-06-13T22:48:00
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Post: 11900976
Thumbs down

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?


Originally Posted by Magplug
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.
mechpowi
2025-06-13T22:50:00
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Post: 11900977
Originally Posted by gdandridge
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:
  1. Shortly after rotation, with a positive rate of climb established, the flight crew commands gear up .
  2. The gear retraction sequence initiates ; the main gear bogies tilt forward , consistent with the start of retraction.
  3. The right engine fails first , resulting in a loss of right hydraulic system pressure . Consequently, the right MLG door does not open .
  4. The left MLG door, still powered by the left hydraulic system, opens .
  5. 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 .
  6. The ram air turbine (RAT) deploys , consistent with total engine and electrical power loss.
  7. With the loss of thrust from both engines , the aircraft loses lift and enters an unrecoverable descent, tragically ending in impact.
This sequence would explain the partially completed gear retraction and the asymmetric gear door position observed in the video evidence. It\x92s worth noting that the timing of the hydraulic losses would have to be very close together \x97 potentially within seconds \x97 which aligns with a dual engine failure shortly after take-off . In such a scenario, asymmetric thrust would be minimal or non-existent , making the aircraft\x92s attitude appear otherwise stable in its descent.

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.
This scenario would offer a tragically plausible explanation for the aircraft\x92s behavior and the observed configuration in its final moments. Of course, the official investigation will provide the definitive answers , and we must await their findings.

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).
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.

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njc
2025-06-13T22:59:00
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Post: 11900982
Originally Posted by Magplug
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.
No argument on the flaps.

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.

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buzzer90
2025-06-13T23:09:00
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Post: 11900987
Originally Posted by Magplug
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.
People should be made to read this before posting!

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TURIN
2025-06-13T23:20:00
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Post: 11900991
Originally Posted by GVFlyer
The RAT sounds to be deployed in some videos. Does the RAT deploy automatically on the B787?
Please read this thread first before asking a question, it has been answered several times.
Yes, the RAT will deploy automatically in the event of a loss of both AC Busses, both engines or all hydraulics.
It can be deployed manually via a guarded push button switch on the overhead panel.

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appruser
2025-06-13T23:21:00
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Post: 11900993
Combining all the bits and pieces of info from this thread so far, IMO we can theoretically sequence it thus using the video from the left:

00:18 Rotation. Normal takeoff config.
00:24 Gear up starts. per Raffael with FF.
......... FR24 ADSB last transmission (71ft, 172kt) just before runway threshold. Matches with video aircraft altitude at 1/2 wingspan.
......... ? Full power flameout leaves N2 ~ 60%; Airspeed < 200k so N2 will decay to 15% in 8-10s?
......... ? Takeoff EGT of 900C needs 25-35s to fall below 250C ?
00:27 Gear up stops. per Raffael with FF. Bogies tilted.
......... ? APU starts. 20-55s to 95%N?
......... Per 787 dual-engine fail/stall memory items, PM initiates Fuel Cutoff and Run.
00:28 Visible loss of thrust. Alt ~ 200ft using aircraft wingspan as measure.
......... Matches with eyewitness "within 5-10s ... it was stuck in the air".
......... Per 787 dual-engine fail/stall memory items, PM initiates RAT Switch for 1s. Whether auto or manual, the RAT initiates.
......... RAT "bang" heard by survivor
......... RAT coming online accounts for eyewitness "lights started flickering green and white".
......... Per 787 QRH below 1000ft, PF makes no change to Main Landing Gear and flaps, aircraft pointed straight for best glide.
00:31 Descending visibly, somewhere beyond the runway threshold. Alt ~ 200ft using aircraft wingspan as measure.
......... ? Because EGT > 250C FADEC blocks fuel (T-HOT hot restart inhibit?) so no relight though N2 > 15% ?
......... 787 glide ratio between 16:1 to 25:1 with MLG down, Flaps 5. About 15-20s and 3-5000ft of glide from 200ft?
......... Some flap accounts for the ground pictures.
00:34 ? N2 has presumably decayed to 15%, FADEC flips to X-START: airspeed outside envelope? No hope of relight now.
......... PM/PF transmits Mayday?
......... Video showing RAT deployed.
00:46 APU reaches some fraction of 95%N (APU sound accounting for survivor's perception of thrust?).
00:48 Impact. 4200ft from descent start, 3990ft from airport boundary road. 17s from visible descent start.

if this is a valid sequence, the only remaining question is why the dual-engine failure at ~200ft agl?

with condolences to the families and people affected.

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GVFlyer
2025-06-13T23:40:00
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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?