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

TachyonID
2025-06-15T06:06:00
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Post: 11902132
Three firm pieces of evidence RAT deployed.

Auditory

Visual

Survivor statement

And, oh by the way, the A/C reported "Power Loss", implying loss of thrust on both sides. Which, ALSO, would drop the RAT.


High certainty at this point that RAT deployed. So you're back to wondering about the loss of thrust-- the big hole in the cheese.

5 users liked this post.

MaybeItIs
2025-06-15T06:09:00
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Post: 11902135
Originally Posted by Icarus2001
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.
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I guess it all depends on what you mean!

If the fuel supplies were cut off, causing the engines to stop, is that engine failure ? I'd say not, nothing wrong with the engines until they impacted the buildings etc.

No evidence of RAT deployment - but you're specifically restricting "the evidence" to a blurry amateur video. That alone is not great evidence, but why does that video exist at all? When they lift the relevant section of fuselage, RAT deployment or not is going to be fairly apparent. And Circumstantial evidence is still evidence, no?

No evidence of electrical failure? Do you know that from the downloaded Flight Data?

freshgasflow
2025-06-15T06:13:00
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Post: 11902136
Mayday call

I think there is uncertainty about contents of mayday call. Most media mention the word mayday with no reference to thrust etc. I wonder if conjecture has become fact.

Originally Posted by TachyonID
Three firm pieces of evidence RAT deployed.

Auditory

Visual

Survivor statement

And, oh by the way, the A/C reported "Power Loss", implying loss of thrust on both sides. Which, ALSO, would drop the RAT.


High certainty at this point that RAT deployed. So you're back to wondering about the loss of thrust-- the big hole in the cheese.
Compton3fox
2025-06-15T06:25:00
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Post: 11902143
Originally Posted by aeo
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.
How about TCMA shuts down both engines for some unknown reason, then AC power fails and RAT deploys. I agree is very low probability but these very low probability events have happened in the past. I just posted AA191 as one example...

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Icarus2001
2025-06-15T06:31:00
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Post: 11902144
I guess it all depends on what you mean!

If the fuel supplies were cut off, causing the engines to stop, is that engine failure ? I'd say not, nothing wrong with the engines until they impacted the buildings etc.

No evidence of RAT deployment - but you're specifically restricting "the evidence" to a blurry amateur video. That alone is not great evidence, but why does that video exist at all? When they lift the relevant section of fuselage, RAT deployment or not is going to be fairly apparent. And Circumstantial evidence is still evidence, no?

No evidence of electrical failure? Do you know that from the downloaded Flight Data?
A thrust reduction is not an engine failure. Engine shutdown due to an action of crew (or inaction) is not a failure.

There is no evidence of an electrical failure. What evidence? A surviving passenger thought he saw flickering lights? Give me a break.

The word evidence in English has a very specific meaning.

Look for the simplest explanation here and then ask why the worldwide B787 fleet is still flying with no urgent inspection requirements from Boeing or GE. Think about that "evidence".

6 users liked this post.

Compton3fox
2025-06-15T06:38:00
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Post: 11902150
Originally Posted by bal00
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.
Is this the correct image?


3 users liked this post.

Compton3fox
2025-06-15T06:48:00
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Post: 11902156
Originally Posted by bakutteh
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.😖🥴😬
If the photo of the flaps deployed at the accident site is actually F1 not F5 or if the flaps were pushed out during impact, then this is certainly plausible. I will look for the photo but it's in the thread somewhere. Others are stating they see a gap between the wing and the flap as an argument for the flaps deployed at F5. This was after the decent started..

However, I think their reaction would likely be to apply more power. I know mine would be. But anything is possible!
kristofera
2025-06-15T07:01:00
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Post: 11902167
Originally Posted by NWSRG
This thought had crossed my mind...but then the RAT suggests a loss of the electrical system. And I'm not sure how the two could be linked?
I'm absolutely not saying it would be the primary cause, but just mentioning that it could be contributing to one or more sensors providing bad data to the various systems (and humans) involved. Just one possible additional hole in the cheese.
Icarus2001
2025-06-15T07:06:00
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Post: 11902171
If the aircraft had flaps deployed (the crash site photos look like it), flight controls working (no indications they weren't), and the thrust levers pushed full forwards, there is very very little that will cause it to sink other than lack of thrust.
Brilliant, now what is your point? Are you suggesting a double engine failure, a roll back to idle thrust or an incorrectly set AAI causing VNAV level off and a thrust reduction. You can only choose one.

For the team pointing to the RAT out as a failure indicator, it could have been deployed by the crew after the initial reduction in climb performance. I am not convinced it is deployed but it really does not make a convincing argument for any type of failure.

For the children on holiday, yes I fly transport category jets, current on two types.
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Pinkman
2025-06-15T07:27:00
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Post: 11902184
Originally Posted by Australopithecus
1. The original video, not the video of a video, has the distinctive audio signature of a deployed RAT.

2 That video shows something dangling down where the RAT is located.

3. There are no typical engine sounds heard.

4. The flaps are extended in that video, and the slats at least are extended in the wreckage pictures.

5. There was no tail strike, so you would conclude that the performance figures were at least close to the actual mass and thrust required.

6. Given the above, and the straight flight path without rudder deflection which ends in a crater instead of Gatwick, you pretty much have all the evidence you need to conclude that there wasn\x92t sufficient thrust and that what little thrust there may have been was symmetrical.

7. While there are many things common to both engines, the most frightening are a system failure and inappropriate crew action. Oh, and some previously unheralded MX action.
To me, the last sentence of (7) in Australopithicus' post nails it and here's why: We already know that this aircraft was cannibalized for spares as was apparently customary at AI and then brought back into service. The problem with this MX culture is that you lay yourself open to the "law of unintended consequences", such as replacing something with a part or pcb/software version that looks right and fits/works but may not perform as designed either physically (think Air Transat - Azores) or software wise (think the "roll back" bug). It isnt necessarily a problem if there is decent paperwork accompanying and authorising this "borrowing" but you can be sure that the investigation will want to see traceability paperwork.

Last edited by Pinkman; 15th Jun 2025 at 10:43 .

1 user liked this post.

Compton3fox
2025-06-15T07:34:00
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Post: 11902190
Originally Posted by Icarus2001
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 engine failure - Not true. No engine noise on video where you would expect TO or TOGA power to be in use. Mayday call stating No Power

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 .

12 users liked this post.

Lead Balloon
2025-06-15T07:42:00
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Post: 11902199
Re the RAT, Icarus, what are your thoughts on this:

3 users liked this post.

tumtiddle
2025-06-15T07:48:00
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Post: 11902201
I can understand dismissal of the RAT theory from the single frame image being passed around, but if you watch the video in context, you can see it there. If the dark spots as circled in the YouTube preview above were only there in a frame or two, they could still be dismissed as a video/compression artefact, but they're not. They're there on several frames and move perfectly with the rest of the airframe. It's hard to see how that is anything but the RAT.

7 users liked this post.

Icarus2001
2025-06-15T07:57:00
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Post: 11902205
The better quality video does show something. It certainly could be the RAT. Automatic or manual deployment?
Assuming GE receive data from these engines in flight, a massive failure would prompt a swift communication from GE. Or a massive electrical issue could put Boeing on edge and also prompt urgent inspections on their aircraft.
Since here we are two days after the EAFR was found then either both the aircraft manufacturer and the engine manufacturer know they are off the hook. That can only be for one of two reasons. They know there was a maintenance issue with this aircraft ( no IFE and call buttons?) or they know it was a handling error.
Of course, tonight we may get urgent bulletins from Boeing or GE but the longer that does not happen, as Bloggs wisely stated, then we are left with a grim reality. Send in the clowns.

5 users liked this post.

VR-HFX
2025-06-15T08:04:00
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Post: 11902209
Originally Posted by Icarus2001
Brilliant, now what is your point? Are you suggesting a double engine failure, a roll back to idle thrust or an incorrectly set AAI causing VNAV level off and a thrust reduction. You can only choose one.

For the team pointing to the RAT out as a failure indicator, it could have been deployed by the crew after the initial reduction in climb performance. I am not convinced it is deployed but it really does not make a convincing argument for any type of failure.

For the children on holiday, yes I fly transport category jets, current on two types.
Yes indeed. I strongly leant toward the incorrectly set AAI and VNAV capture and level off as the a/c reportedly reached max alt of 625ft or about 450ft AGL. Even with startle factor, recovery should have been quite possible. The video I have seen (not the video of the video) clearly shows the RAT deployed and you can hear the whine of the turbine and virtually no engine noise . This complicates it for me as there is no logical reason to deploy the RAT in the VNAV/level off scenario.

4 users liked this post.

Someone Somewhere
2025-06-15T08:08:00
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Post: 11902212
Originally Posted by Icarus2001
Originally Posted by Icarus2001
A thrust reduction is not an engine failure. Engine shutdown due to an action of crew (or inaction) is not a failure.

There is no evidence of an electrical failure. What evidence? A surviving passenger thought he saw flickering lights? Give me a break.

The word evidence in English has a very specific meaning.

Look for the simplest explanation here and then ask why the worldwide B787 fleet is still flying with no urgent inspection requirements from Boeing or GE. Think about that "evidence".
Uncommanded thrust reduction sure sounds like engine failure to me. Neither US1549 nor Ryanair 4102 suffered flameout until the former attempted to switch the engines off and back on. I don't think anyone is going to say those weren't engine failures.

If the aircraft had flaps deployed (the crash site photos look like it), flight controls working (no indications they weren't), and the thrust levers pushed full forwards, there is very very little that will cause it to sink other than lack of thrust.
Brilliant, now what is your point? Are you suggesting a double engine failure, a roll back to idle thrust or an incorrectly set AAI causing VNAV level off and a thrust reduction. You can only choose one.

For the team pointing to the RAT out as a failure indicator, it could have been deployed by the crew after the initial reduction in climb performance. I am not convinced it is deployed but it really does not make a convincing argument for any type of failure.

For the children on holiday, yes I fly transport category jets, current on two types.
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In reply to you, I am solely stating that it's a thrust-side problem. I think I somewhat misinterpreted your post as it looks like you might have been saying that anyway.

In general, I think it's looking like dual engine failure/shutdown cutting electrics. I agree that why it occurred is very unclear. Outside chance of total electrical failure causing dual engine failure rather than the other way around, but that would perhaps be even more concerning a design failure.

Similar to Jeju, we also have what is looking increasingly like a loss of ADS-B data at the moment things went wrong, not just a loss of coverage.

That gives:
  • Sound of RAT
  • Visible RAT
  • (edit: APU door open implies APU autostart)
  • Loss of ADS-B out
  • Near-total loss of thrust.
The alternate theories seem to be a) flaps (basically discounted), b) suction feed failed after total electrical failure, or c):
  • A/T rolled engines back
  • Crew interpreted this as dual engine failure
  • Crew didn't push throttles forward
  • Crew did switch each engine off & on again and maybe deployed RAT manually as well.

Originally Posted by Icarus2001
Assuming GE receive data from these engines in flight, a massive failure would prompt a swift communication from GE. Or a massive electrical issue could put Boeing on edge and also prompt urgent inspections on their aircraft.
I think it has been suggested that the upload only happens every 30 minutes or so.

Last edited by Someone Somewhere; 15th Jun 2025 at 08:21 .
Fifthleg
2025-06-15T08:09:00
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Post: 11902214
It is most likely the RAT deployed in the picture as it is also most likely the APU initiated an AUTO START, by evidence that the intake flap is partially open. Given it takes 20-30 seconds to fully open, the resting position looks about right given the time line that all 4 VFSGs went off-line.

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Chuck Canuck
2025-06-15T08:22:00
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Post: 11902223
Originally Posted by bakutteh
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.😖🥴😬

This is a very plausible scenario. Above 400 ‘ AGL, memory items.

4 users liked this post.

amsm01
2025-06-15T08:54:00
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Post: 11902253
Originally Posted by bakutteh
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\x92 imagination.😖🥴😬
(Sorry, Airbus here and not familiar with Boeing) Flap 5 to 1 reduction on the Boeing triggers autothrust reduction, is that correct? If so, are there any other conditions that need to be met for this to happen like being in some kind of takeoff mode? Just thinking whether this would have potential otherwise in other regimes to cause issues, discontinued approach perhaps.

Am slightly puzzled as to why if flap reduction triggering climb thrust is part of the standard logic (and presumably clean-up technique) then partial dual thrust loss wouldn\x92t be immediately recognised as the classic symptom of gear / flap retraction handling error? I presume Boeing pilots / air India are just as aware of this it as everyone else, strikes me as odd that one would immediately go into full dual EF mode. My instinctive reaction without knowing the Boeing would be to firewall both TLs, would this have worked in the early flap retraction logic scenario? Many thanks all
Screamliner
2025-06-15T08:58:00
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Post: 11902261
So one thing to keep in mind, the RAT can be deployed manually, but also comes automatically when certain conditions arise, everybody here is assuming it\x92s only on dual engine failure but there are 4 more conditions that trigger the RAT,

- all three hydraulic system pressures are low

- loss of all electrical power to the captain and first officers flight instruments

- loss of all four EMP\x92s (electro motor driven pump) and faults in the flight controls system occur during arrival

- loss of all four EMP\x92s and an engine fails during take off.

This all comes directly from B787 FCOM,



If we assume that what our survivor saw is correct, maybe it was an electrical failure, the aircraft had electrical issues in Delhi during departure and I checked the crash video again, I don\x92t see the strobe lights (neither wing or tail) and also no Anti collision light either. this might also explain the self starting APU on loss of the electrics (engine driven generators). That could also result in a loss of situational awareness with the speed, because of no indication, even the HUD would not work. The mayday call would still be doable because the radios work from the battery.