Posts about: "RAT (All)" [Posts: 683 Pages: 35]

That very much sounds like the RAT is deployed as the aircraft goes by the camera.

The noise certainly matches " target="_blank"> The noise certainly matches

Hard to say and the noise could be a fake. It's hard to tell what's real these days.

Comparing the sound at the beginning of this video:
https://www.reddit.com/r/ahmedabad/s/Oz5hQzDiu5

With the sound of the 787 at the 1:14 mark


It sounds like it had the RAT deployed?

That sure sounds like a RAT is deployed on that video, unless it\x92s a vehicle passing by.

I think I can somewhat see it deployed during the pitch up.

[img]image.jpg[/img]


Pixelation is a bit absurd, but that looks a bit like a RAT to me in the lower right.

No speculation as to what caused the crash, but a couple of points. If there was an inadvertent retraction of flaps instead of gear, this could potentially be remedied by reselecting flaps promptly once recognised. Whether the startle factor would allow it is another thing.

If the RAT is indeed out and there was some sort of powerplant issue, ie. double engine failure, I don't think I would be in a hurry to retract the gear either. In fact it may well have been put down again in that scenario.

Regardless, awful footage to watch. RIP.

Daily Mail have already been quoting this thread about the RAT.

At least one press report stating 'engine failure' was mentioned
Air India pilot said 'engine failure' in mayday call before horror crash | World | News | Express.co.uk

Not seen this anywhere else, and bearing in mind the source, I'd take as a huge pinch of salt, though with the RAT potentially deployed, there may be some credence

How horrible. From what has surfaced so far, it does appear that the aircraft became airborne and got to a reasonable height and groundspeed, within parameters for a normal takeoff. The video with RAT-like audio and the snapshot from another video showing hints of RAT deployment seem to be the biggest clues so far: flaps and gear are a minor issue compared with a serious power loss, although loss of electrical power would trigger the RAT if it uses the same logic on the 787 as earlier Boeings.

That you can hear the RAT on the video over what should be engines at takeoff thrust at that point adds credence to the theory, as does reports of a MAYDAY.

For an aircraft that will likely have TOGA pressed and be at a high power setting (plus the RAT deployed) it sounds awfully quiet.
Perhaps the gear was down because they knew they were going to force land due to lack of thrust.
(Only a 738 driver), but the electric pumps to drive the hydraulics is much slower than the engine driven pumps and so flap selection / re-selection could be not as expected.

RIP to all involved.

Just looking at the footage, I think it unlikely that the AC was in a (full) stall. There is considerable upward wing flex, which speaks of consistent lift being produced. While a fully stalled wing will still produce SOME lift, I doubt it would be enough to account for that amount of flex. Maybe (!) the AC stalled in the last 1 or 2 seconds with the aggressive nose-up attempt, but we don't get to see that. Also, what is this discussion about the RAT? Unless someone has extremely quickly faked the audio on the video, it is pretty clear that the engines were running. (Both of them, there is some slight interference pattern I (maybe imagine) to hear. Plus, I cannot see any rudder applied. It appears to me that they simply had not enough power available, or were overloaded. Possibly mis-configured in terms of flaps/slats.

787 gear and flaps/slats are both on the centre system, powered by 2x big electric pumps and no EDPs, so retraction should be minimally impacted by engine failure assuming electric power was still available and reconfiguration worked. Note the 787 has two generators per engine so generator failure is also unlikely to contribute, unless both engines failed taking out all four generators (and presumably no APU running).

From that thread, I believe it was discussed that on most/all other large transports, deploying the RAT re-powers the CVR/FDR. The 737 didn't have that happen because no RAT. You may still get a few second gap while the RAT deploys.

The 787 has 2x Enhanced Airborne Flight Recorders (EAFR), which each record both cockpit voice and flight data. I expect they are also fitted with the dedicated batteries that the Jeju was a year or two too early to require. Per the NTSB , the forward recorder has a 10-minute backup battery.

Hopefully flight data is not going to be an issue for this investigation.

The suggestion is that the buzzsaw/propeller sound is the RAT; it does sound a bit like an interference pattern, but you don't get the engine roar with it.

It's also maybe visible in a few stills (e.g. post 64).

The audio is not great and kind of whiny. Even at the end when the crash happens, it does not sound robust.

Likely: this is not the RAT sound; it is just poor audio pickup.

Just to confirm.
The 787 is an aircraft which likes to, performance wise, use all of the available runway for takeoff. Sometimes you can be sat in the 787 and as you are rolling down the runway, you start wondering if Rotate has been called or not. It loves taking up all of the runway.

Nevertheless, there are some interesting speculations over on X. One guy even claimed the Captain was in the lavatory during the accident...

Many people have noted what appears to be the RAT deployed in the video footage suggesting dual engine failure. Possible wrong engine shutdown? But who diagnoses and actions an engine failure and shutdown below 400ft?

TE Flaps are extended, flap gaps between the wing and the flap element are observable. This is not an aberration of the spoiler position, you can see the nacelles through the gap, and that means the flap can not be in the retracted position.

An error of the TE flap deployed position, say between flaps 5 or 15 is not going to cause a stall event.

The flap has not been retracted instead of the gear.

Double engine failure... India. birds, always a latent threat. No rudder deflection, no aileron deflection, so it's not a SE problem, any engine issue is affecting both engines.

Pitch control and roll is not compromised in the video. The crew put out a mayday, not sounding like an electrical fault or distraction.

any funerals near by?

Incorrect TO thrust setting would not present in the video as recorded. Low thrust results in low acceleration, and extended distance to rotate. after rotate, low thrust results in low climb rate, and can result in the crew over pitching where the aircraft has obstructions that the crew have to avoid. the video appears to show the pitch increasing at a point where the aircraft is already unable to climb, not the other way round. An outside possibility.

For survivors, any from the aircraft will be a miracle, and mainly from the rear of the plane near door 3 area, if any. Plane is still striking tank traps at 70m/sec +, high ANU, it's not a high survivability event. Occupants in the buildings along the flight path will have a high fatality rate as well. This is going to be a high toll event in the aircraft and on the ground. Bad day at VAAH. RIP.

\x94 And ex senior pilot, Captain Saurabh Bhatnagar, said: "It looks, prima facie, like a case of multiple bird hits wherein both the engines have lost power. The take-off was perfect and just, I believe, short of taking the gear up, the aircraft started descending, which can happen only in case the engine loses power or the aircraft stops developing lift. Obviously, the investigation will reveal the exact reason."

I've watched several versions of this fly-by and crash video, and only this version has this buzzing sound in it. The audio in this version is very different from the others. And when I went frame by frame looking for the RAT, it turns out to actually be the nose gear, which, because of the angle in the later frames, seems to be under the right wing. In the early frames, you don't see anything looking like the RAT.

Considering the RAT is 100% out as evidenced from footage both visually and audibly; the initial conclusion can only be both engines have failed, or one failed, and the other unfortunately shut down.

I'm not convinced the RAT is out. I've looked several times and can't see it on any of the videos.
Happy to be corrected.

check the video in the first page or so. Can clearly hear the RAT out. A few further down there is an image with it clearly visible