2025-06-13T06:46:00
permalink Post: 11900071
Subjects: RAT (All)
2025-06-13T07:24:00
permalink Post: 11900099
My theory on this is a wrong weight/temperature entry, too much derating, attempted take-off in too low an energy state and subsequent departure stall.
From the airport cam video, the aircraft seems to stick off just at the end of the runway.
Both engines are working at full blast until at least obstacle clearance height, they kick up unusual amounts of dust for a take-off.
Theoretical sequence of events:
1. Pilots entered the wrong take off perf data
2. During the take-off roll they realize that the aircraft isn't picking up enough speed but too late to reject and firewall the throttles
3. They use up the whole runway and get the aircraft off the ground in ground effect
4. Ground effect ends and they fail to maintain a positive rate of climb, hence gears stay down
5. Aircraft stalls and sinks into the ground
Textbook departure stall and failure to pitch down to recover from it.
From the airport cam video, the aircraft seems to stick off just at the end of the runway.
Both engines are working at full blast until at least obstacle clearance height, they kick up unusual amounts of dust for a take-off.
Theoretical sequence of events:
1. Pilots entered the wrong take off perf data
2. During the take-off roll they realize that the aircraft isn't picking up enough speed but too late to reject and firewall the throttles
3. They use up the whole runway and get the aircraft off the ground in ground effect
4. Ground effect ends and they fail to maintain a positive rate of climb, hence gears stay down
5. Aircraft stalls and sinks into the ground
Textbook departure stall and failure to pitch down to recover from it.
Subjects: RAT (All) RAT (Deployment) Takeoff Roll
2025-06-13T11:45:00
permalink Post: 11900402
I didn\x92t think this could be a dual engine failure related accident until reports of RAT deployment started to gather steam.
A few years back a B787 previously had a dual engine shutdown after rollout when the TR was deployed too quickly and not allowing the air/GND logic time to transition to ground mode before the TR deployed. If the TCMA had inadvertently latched the TR deployment from the previous rollout then it theoretically could be possible to shutdown on transition back to air mode.
Anything is possible with these high tech machines.
A few years back a B787 previously had a dual engine shutdown after rollout when the TR was deployed too quickly and not allowing the air/GND logic time to transition to ground mode before the TR deployed. If the TCMA had inadvertently latched the TR deployment from the previous rollout then it theoretically could be possible to shutdown on transition back to air mode.
Anything is possible with these high tech machines.
been examples in the past where it does something it wasn't supposed to do, causing an incident.
Subjects: Dual Engine Failure Engine Failure (All) Engine Shutdown RAT (All) RAT (Deployment) TCMA (All)
2025-06-14T13:58:00
permalink Post: 11901509
Subjects: RAT (All) RAT (Deployment)
2025-06-14T14:50:00
permalink Post: 11901548
I don’t agree with either of those assessments at all. One strongly pushing the flap scenario and the other a software fault. The flap one has been done ad nauseam, I won’t repeat it. A sudden software glitch on a decade plus old model is a stretch and likewise a call to ground the entire fleet immediately.
of course like everyone else I have absolutely no idea what actually happened but I am willing to bet the explanation will be simpler than everyone is expecting.
I am not going to speculate further as I believe it is a waste of time without further information.
For the record I am not b787 rated but I do have Boeing and airbus narrow body and wide body time and i struggle to forsee a situation where the aircraft falls out of the sky at 200ft without a very serious error of some description.
of course like everyone else I have absolutely no idea what actually happened but I am willing to bet the explanation will be simpler than everyone is expecting.
I am not going to speculate further as I believe it is a waste of time without further information.
For the record I am not b787 rated but I do have Boeing and airbus narrow body and wide body time and i struggle to forsee a situation where the aircraft falls out of the sky at 200ft without a very serious error of some description.
Last edited by Compton3fox; 14th Jun 2025 at 14:53 . Reason: added a line
Subjects: None
13 users liked this post.
2025-06-14T15:28:00
permalink Post: 11901574
Just to throw another wrench in the gears, the airplane flew in so it should fly out.
Except it didn\x92t.
We can over analyze for another 1000 replies, fact remains the airplane flew in without major issues and spend two hours on the ground at the gate.
Catastrophic failure just doesn\x92t randomly happen.
The elefant in the room is Boeing.
If this turns out to be an airplane issue rather than a crew action it may be the end of them.
You can\x92t have a plastic electric airplane where the engines randomly stop.
Auto throttle thrust reduction can be perceived as power loss.
Except it didn\x92t.
We can over analyze for another 1000 replies, fact remains the airplane flew in without major issues and spend two hours on the ground at the gate.
Catastrophic failure just doesn\x92t randomly happen.
The elefant in the room is Boeing.
If this turns out to be an airplane issue rather than a crew action it may be the end of them.
You can\x92t have a plastic electric airplane where the engines randomly stop.
Auto throttle thrust reduction can be perceived as power loss.
Subjects: None
2 users liked this post.
2025-06-14T15:33:00
permalink Post: 11901579
It\x92s the elephant in the room regarding the audio, isn\x92t it, but I am not prepared to say either way. There simply is too much city background noise/ambience to discern this from the engine noise from a landing 787.
Of course one taking off would have a different signature. If anyone can point point to one taking off with the rat out we could compare.
What I find interesting is that I don\x92t see any evidence in the audio of the engine spooling down, which would leave a recogniseable pattern in the audio one should think. So either it is down so much that the fan rpm is down to windmilling already, or it is simply low enough in volume to be already masked by the ambience.
So taking this and moving into speculative territory for a moment, I think I read somewhere that the video with audio starts 17 seconds after the wheels left the ground.
Provided the engines were windmilling the video audio since I haven\x92t been able to find any obvious spool down, can anyone say anything meaningful on how long it takes for the engines to spool down to windmilling rpm?
we can then backtrack from the point the video starts. How does that timing then coincide with the ADS-B data ceasing to transmit, for instance?
Putting back in the more strictly data-driven hat, I am not prepared to say so far anything about the engine working or not. You guys know more anout why the rat is out.
Of course one taking off would have a different signature. If anyone can point point to one taking off with the rat out we could compare.
What I find interesting is that I don\x92t see any evidence in the audio of the engine spooling down, which would leave a recogniseable pattern in the audio one should think. So either it is down so much that the fan rpm is down to windmilling already, or it is simply low enough in volume to be already masked by the ambience.
So taking this and moving into speculative territory for a moment, I think I read somewhere that the video with audio starts 17 seconds after the wheels left the ground.
Provided the engines were windmilling the video audio since I haven\x92t been able to find any obvious spool down, can anyone say anything meaningful on how long it takes for the engines to spool down to windmilling rpm?
we can then backtrack from the point the video starts. How does that timing then coincide with the ADS-B data ceasing to transmit, for instance?
Putting back in the more strictly data-driven hat, I am not prepared to say so far anything about the engine working or not. You guys know more anout why the rat is out.
Subjects: ADSB Generators/Alternators
2025-06-14T17:42:00
permalink Post: 11901687
Subjects: Fuel (All) Fuel Pumps
2025-06-14T17:53:00
permalink Post: 11901693
I have seen your previous posts about this, and I happen to agree. Visually, as a lay man non visuals expert, I am in your \xabcamp.\xbb
However, the rat is small, and the artifacts are plentiful. Small sensor, compressed video, compressed upload, zoom, it is in short an awful source.
However, the RAT is a much better noisemaker, and the audio signature is much more obvious than it\x92s visual appearance in this case, and though the recording isn\x92t fantastic quality, there was more than enough information there to objectively conclude the RAT is out. And that is my professional, on the weekend, opinion.
I want to ask a pretty frank question for all of you, and I hope it is ok, from an audio specialist non-pilot:
Provided the engines spooled down. Provided the RAT is out. (There are no explosions, no bird strikes.)
Isn\x92t software and previous electrical failures a red herring too?Would anything but a complete fuel shut off lead to this result? That still leaves everything from the Fate is the Hunter plot, to Airbus A350 center consoles and Alaska 2059 open as root causes.
However, the rat is small, and the artifacts are plentiful. Small sensor, compressed video, compressed upload, zoom, it is in short an awful source.
However, the RAT is a much better noisemaker, and the audio signature is much more obvious than it\x92s visual appearance in this case, and though the recording isn\x92t fantastic quality, there was more than enough information there to objectively conclude the RAT is out. And that is my professional, on the weekend, opinion.
I want to ask a pretty frank question for all of you, and I hope it is ok, from an audio specialist non-pilot:
Provided the engines spooled down. Provided the RAT is out. (There are no explosions, no bird strikes.)
Isn\x92t software and previous electrical failures a red herring too?Would anything but a complete fuel shut off lead to this result? That still leaves everything from the Fate is the Hunter plot, to Airbus A350 center consoles and Alaska 2059 open as root causes.
Subjects: Bird Strike Fuel (All) Fuel Cutoff RAT (All)
3 users liked this post.
2025-06-14T18:01:00
permalink Post: 11901698
We can debate over a poor quality photo but the audio evidence presented earlier today is pretty conclusive.. The RAT was out.
Subjects: Audio Analysis Gear Retraction RAT (All)
17 users liked this post.
2025-06-14T21:57:00
permalink Post: 11901873
Not to mention the fact the flaps were selected when you view pictures from the accident site. Dare I mention the RAT being deployed too? That does not happed if you select flaps up at the wrong time.
Subjects: RAT (All) RAT (Deployment)
2025-06-14T22:01:00
permalink Post: 11901878
That\x92s not a false conclusion if in fact hydraulics were lost. I dont think that was the case and if it was engine driven hydraulic pumps have normal output all the way down to idle and actually further. I dont think the RAT deployed for any reason and i am not sure that has been confirmed.
Subjects: Audio Analysis Hydraulic Failure (All) Hydraulic Pumps RAT (All) RAT (Deployment)
1 user liked this post.
2025-06-14T22:13:00
permalink Post: 11901888
From tdracer
However, TCMA is only active on the ground (unfamiliar with the 787/GEnx TCMA air/ground logic - on the 747-8 we used 5 sources of air/ground - three Radio Altimeters and two Weight on Wheels - at least one of each had to indicate ground to enable TCMA). TCMA will shutdown the engine via the N2 overspeed protection - nearly instantaneous. For this to be TCMA, it would require at least two major failures - improper air ground indication or logic, and improper TCMA activation logic (completely separate software paths in the FADEC). Like I said, very, very unlikely.
However, TCMA is only active on the ground (unfamiliar with the 787/GEnx TCMA air/ground logic - on the 747-8 we used 5 sources of air/ground - three Radio Altimeters and two Weight on Wheels - at least one of each had to indicate ground to enable TCMA). TCMA will shutdown the engine via the N2 overspeed protection - nearly instantaneous. For this to be TCMA, it would require at least two major failures - improper air ground indication or logic, and improper TCMA activation logic (completely separate software paths in the FADEC). Like I said, very, very unlikely.
Subjects: Engine Over-speed (All) Engine Shutdown (Over-speed) FADEC GEnx TCMA Logic N2 Over-speed TCMA (Activation) TCMA (Air-ground Logic) TCMA (All) TCMA (Improper Activation) TCMA (Shutdown) Weight on Wheels
1 user liked this post.
2025-06-15T05:47:00
permalink Post: 11902128
But at some point software decisions converge to a single point, a single decision, to simplify for instance the subroutine where all of the decisions have been taken to trigger an output (a shutdown signal, for instance). And if, again for instance, you accidentally jump into this subroutine (whether because of buffer overflows or mistakes in the preceding logic), then you can trigger the output incorrectly.
Of course you can have two or three systems that are coded by different teams, using different languages, running in different hardware, even if they are fed from the same sensors, as long as you have many sensors (as tdracer has indicated, 5 inputs on the 747 for instance - although only needing 2 to be true does seem to reduce that margin for error somewhat).
If these two or three systems all have to send independent signals to the downstream hardware (the engine in this case) and the engine requires more than one signal to take the dangerous action like shutdown, then you're more protected, but that doesn't seem to be how the 787 works from the descriptions here by the experts like td and fdr. But please correct me if I'm wrong on that.
Its hard to imagine how else you could simultaneously cut both engines any other way, as tdracer said, other than human action or by software command. And software command means software failure. So information and discussion about exactly how redundant the software that takes this decision is would seem a good direction to move this discussion in. Is it truly only redundant 'internally' to itself, the module that sends this message to the engines? We heard about the 32 bit overflow bug that can shutdown engines - is it really that hard to believe that it has no other similar bugs when that one slipped through the testing?
Of course you can have two or three systems that are coded by different teams, using different languages, running in different hardware, even if they are fed from the same sensors, as long as you have many sensors (as tdracer has indicated, 5 inputs on the 747 for instance - although only needing 2 to be true does seem to reduce that margin for error somewhat).
If these two or three systems all have to send independent signals to the downstream hardware (the engine in this case) and the engine requires more than one signal to take the dangerous action like shutdown, then you're more protected, but that doesn't seem to be how the 787 works from the descriptions here by the experts like td and fdr. But please correct me if I'm wrong on that.
Its hard to imagine how else you could simultaneously cut both engines any other way, as tdracer said, other than human action or by software command. And software command means software failure. So information and discussion about exactly how redundant the software that takes this decision is would seem a good direction to move this discussion in. Is it truly only redundant 'internally' to itself, the module that sends this message to the engines? We heard about the 32 bit overflow bug that can shutdown engines - is it really that hard to believe that it has no other similar bugs when that one slipped through the testing?
Subjects: None
4 users liked this post.
2025-06-15T06:14:00
permalink Post: 11902138
In summary, these billion to one events are only billion to one taking into account what we knew and predicted at the time. Throw in a wild or unpredicted event and all bets are off.
Also, a Billion to 1 event only happens 1 in a billion times. So if you run the sequence 10 billion times, then in theory, it will happen 10 times but it may happen 20 in the 1st 10 billion or 5 and as skwdenyer stated, it can happen at event 1! Toss a coin 20 times and probability says you will get 10 heads and 10 tails but all the tosses are independent, so you could get 20 heads or 20 tails or any other combination. The same applies to billion to 1 events.
Last edited by Compton3fox; 15th Jun 2025 at 07:44 .
Subjects: FAA Hydraulic Failure (All)
9 users liked this post.
2025-06-15T06:25:00
permalink Post: 11902143
So are we now saying total loss of AC power for the RAT activation and activation of TCMA on two very independent engines for the power loss? What are the chances..
I can buy the AC power loss, but TCMA activation as well - That\x92s a stretch. TCMA is available on the ground and on approach and will activate if the engine thrust doesn\x92t follow the Thrust Lever command. On the ground it will shut the engine down (think RTO with engine stuck at T/O). On approach it will reduce the thrust if the engine doesn\x92t respond to the Thrust Lever command ala Cathay Pacific A330 (CMB - HKG) with the fuel contamination incident.
I can buy the AC power loss, but TCMA activation as well - That\x92s a stretch. TCMA is available on the ground and on approach and will activate if the engine thrust doesn\x92t follow the Thrust Lever command. On the ground it will shut the engine down (think RTO with engine stuck at T/O). On approach it will reduce the thrust if the engine doesn\x92t respond to the Thrust Lever command ala Cathay Pacific A330 (CMB - HKG) with the fuel contamination incident.
Subjects: Fuel (All) Fuel Contamination RAT (All) TCMA (Activation) TCMA (Air-ground Logic) TCMA (All)
1 user liked this post.
2025-06-15T06:38:00
permalink Post: 11902150
In this thread there has been a lot of back and forth about whether or not the RAT is visible in the flyover video. I think some of the confusion may stem from the fact that people are watching different versions of the same video. There's a low quality version where someone is pointing a camera at a monitor. This is obviously not good enough to see anything. Then there's a higher quality version that seems to be a direct upload of the video in question. However, because it's hosted on X, there are different versions of that one as well. The player will auto-select the resolution that it thinks is most appropriate for your device, but this could very well be a lower resolution. The highest quality version that I'm aware of is 884x1564. I can't provide a direct link, but if you want to scrutinize the video, I would suggest using a website/app/browser plugin of your choice to download this version first. Don't rely on the X web player.
If people are saying that they can't see anything that looks like a RAT, that may very well be true, depending on which version they're watching.
I don't have the ability to post direct links, but I did take a frame from the highest quality version of the video, and what I see is a RAT-sized, RAT-shaped object protruding from the fuselage in the exact position where you would expect the RAT to be.The image in question has only been cropped and enlarged by a factor of 2. No other editing, processing, sharpening or AI enhancement has been done. If someone else wants to replicate it, the timecode is 00:08.05.
imgur. com/a/YE2q1e3
If someone with link-posting privileges wants to upload the image here, that'd be great.
If people are saying that they can't see anything that looks like a RAT, that may very well be true, depending on which version they're watching.
I don't have the ability to post direct links, but I did take a frame from the highest quality version of the video, and what I see is a RAT-sized, RAT-shaped object protruding from the fuselage in the exact position where you would expect the RAT to be.The image in question has only been cropped and enlarged by a factor of 2. No other editing, processing, sharpening or AI enhancement has been done. If someone else wants to replicate it, the timecode is 00:08.05.
imgur. com/a/YE2q1e3
If someone with link-posting privileges wants to upload the image here, that'd be great.
Subjects: RAT (All)
3 users liked this post.
2025-06-15T06:48:00
permalink Post: 11902156
Do not discount the mistaken early flap retraction scenario too easily. Mull on this:
PF commanded gear up on attaining positive rate of climb, fixating on the HUD.
PM mistakenly raise flap lever from 5 to Flap 1 gate. Thrust reduced to Climb Thrust. Landing gear remained deployed. Massive loss of lift misidentified as loss of thrust. If any one pilot just had a dual engine failure scenario on a recent sim ride, brain and muscle memory would jump to loss of thrust in dual engine, prompting them to accomplish the recall memory items which called for both engine fuel switches to OFF and then RUN, and physically deployed the RAT.
There would be immediate loss of thrust with the engine taking time to recover , if at all, at such low airspeed!
The rest is left for Ppruners’ imagination.😖🥴😬
PF commanded gear up on attaining positive rate of climb, fixating on the HUD.
PM mistakenly raise flap lever from 5 to Flap 1 gate. Thrust reduced to Climb Thrust. Landing gear remained deployed. Massive loss of lift misidentified as loss of thrust. If any one pilot just had a dual engine failure scenario on a recent sim ride, brain and muscle memory would jump to loss of thrust in dual engine, prompting them to accomplish the recall memory items which called for both engine fuel switches to OFF and then RUN, and physically deployed the RAT.
There would be immediate loss of thrust with the engine taking time to recover , if at all, at such low airspeed!
The rest is left for Ppruners’ imagination.😖🥴😬
However, I think their reaction would likely be to apply more power. I know mine would be. But anything is possible!
Subjects: Dual Engine Failure Engine Failure (All) Flap Retraction Flaps (All) Fuel (All) Fuel Cutoff Gear Retraction RAT (All) RAT (Deployment)
2025-06-15T07:34:00
permalink Post: 11902190
No evidence of engine failure
No evidence of RAT deployment from a poor image.
No evidence of electrical failure.
The teams of lawyers in the UK representing 53 grieving families will be working over the weekend to sign up said families to a class action.
This is going to get messy.
No evidence of RAT deployment from a poor image.
No evidence of electrical failure.
The teams of lawyers in the UK representing 53 grieving families will be working over the weekend to sign up said families to a class action.
This is going to get messy.
No evidence of RAT deployment from a poor image . - You can argue Not from the Image but...: 2 independent audio analysis of the video audio shows the sound comes from a deployed RAT plus JB's video. Plus the guys who live in SEA having heard 100's of RATs deployed during test flight have stated that the sound is a RAT.
No evidence of electrical failure . - Not true. Reported cabin emergency lights going off, FR24 feed stopped just as in the 737 South Korea incident in December. APU intake door partially open at crash scene, suggesting an APU autostart.
Now you can call into question the above evidence but to state there is none, is simply not true.
Last edited by Compton3fox; 15th Jun 2025 at 08:23 .
Subjects: APU Audio Analysis Electrical Failure Engine Failure (All) FlightRadar24 Mayday RAT (All) RAT (Deployment) TOGA
12 users liked this post.
2025-06-15T20:52:00
permalink Post: 11902822
After hours of reading I conclude that so far nobody has the slightest clue about what happened.
1: Flaps were down
2: The RAT story is based on a single unsharp video frame. Earlier frames were much sharper but the RAT could not be seen (although there was a sound).
3. Lack of evidence
I could be wrong, in that case please link QUALITY evidence so that we can learn something new.
This way thousands of people are wasting countless hours.
1: Flaps were down
2: The RAT story is based on a single unsharp video frame. Earlier frames were much sharper but the RAT could not be seen (although there was a sound).
3. Lack of evidence
I could be wrong, in that case please link QUALITY evidence so that we can learn something new.
This way thousands of people are wasting countless hours.
Subjects: Audio Analysis RAT (All) RAT (Deployment)
7 users liked this post.