Posts about: "Engine Failure (All)" [Posts: 489 Pages: 25]

The aircraft is refuelled from the same single point source.
If the fuel from the bowser/ground tank was contaminated it would affect both engines.
However, this would also have affected other aircraft at the airport. It could of course been refuelled with the wrong fuel, but that\x92s pretty much unheard of, and big engines like this can pretty much run on anything that will burn.

I think this is the wrong attitude and technique, but it's an opinion.

To me the radio call signals possibly helplessness and confusion.I do not think a pilot who understands what is going on would make the call. He would be too busy trouble shooting. It could be a sign that is was NOT an engine failure or a bird strike ( in both cases they would have mentioned it). Nor a deliberate crash. They had no idea why they could not climb and that tells me they most probably retracted the flaps. Time will tell.

Can the RAT be deployed manually\x85

The only thing that is clear from the footage is that the gear remains down. Which has led to the theory that the loss of lift is a result of the flaps being raised by mistake.

However a deployed RAT would be compelling evidence of dual engine failure or shutdown.

Another explanation for the gear remaining down could be startle/distraction caused by engines rolling back at around rotate or liftoff.

As has already been pointed out, these deployments were deliberate for test purposes and the approaches were done into airfields used by manufacturers for trials. Unless the Air India crew thought it would be fun to see what happened if they deployed the RAT shortly after takeoff, we are looking at something triggered by one or more of:

System-wide electrical issues
Double engine failure
Selection of fuel switch and/or fire switch on both engines

Any speculation about gear, flap, runway, etc. is redundant if the RAT did auto-deploy as it points to a very serious technical issue with the airframe rather than what was done with thrust levers or what the pilots had for breakfast.

I haven\x92t seen what the 787 cockpit looks like on battery power only but on the 777 it gets pretty dark with only the essential P1 instruments and VHF1 available until the RAT comes online, which is a measurable amount of time after deployment is triggered.

Confirmed, as so we can all move on, reference attached. And for the guy that flew 767\x92s for 40 years and didn\x92t know anything about it 😂

There isn't enough clarity on numerous issues, and without answers to the following, zero conclusions can be made as to a possible cause. This is definitely one that could go in numerous directions. Anyone claiming to have the definitive answers must have the FDR data, and I'm assuming that shouldn't take too long to be located and analysed.

1a. Were flaps deployed at start of take off roll?
1b. Were flaps retracted coinciding with climb rate reduction?
2. Did the RAT definitely deploy? The videos are grainy low quality. AI improvement surely isn't reliable.
3. If the RAT deployed, would that indicate complete power loss?
4. Was there any other audio indicating thrust loss or variations during departure?
5. Can we confirm the pilot Mayday indicating thrust loss? If so, that needs investigation as a first priority. The pilot was telling us the cause. Unless we have alternative information he should be believed.
6. Why was the gear not retracted? Distraction, hydraulic failure, flap instead of gear, intentionally, the possibilities are endless.
7. If complete thrust loss occurred, other than a severe fuel issue, what could cause simultaneous flameout? That would be almost unimaginable, yet this is what the pilot allergy said happened. It would have massive ramifications if that gets confirmed.

I don't think the video clips we have are clear enough to say anything at all at this stage. Flaps are hard to see on 787 imo for departure settings. All I can say is it appeared to climb well in the first seconds, then coinciding with the point that gear would usually be retracted, lift appears to very quickly be lost. That indicates sudden speed loss, or lift loss. Speed loss would be thrust, lift loss would be flap retraction if thrust was still available.

The pilot allegedly reported thrust loss, that should be highest on the list of causes imo. In the case of double engine failure without any apparent outside influence visible on videos, that would be quite something for investigators to fathom.

I don't know if anyone has data to show speed trend at the point the aircraft starts to descend, or a better audio for thrust variations at that point. I'm guessing that the update frequency on FR24 would be too slow to show that sudden change at the highest point achieved.

We'll have the answers soon enough, all I can say is there appears to be no clear answers here without the data recorders or clear improved information. Indeed no conclusions whatsoever can be made as to crew actions either.

RIP crew and passengers, condolences to the families.

I'm afraid you've waded in without reading the rest of the thread. The poster you quoted has already explained he lives on the flight path in Everett or Paine, and so hears the test flights of all the aircraft before delivery to airlines.

This seems to be the best summary so far. Based on the detail of the mayday its probably time to rule out the flaps, load shift, and other suggestions. Latest news is a quote from the survivor: " Suddenly, the lights started flickering – green and white – then the plane rammed into some establishment that was there" .

I cant think of any reason for electrical failure and "no thrust" (as per statements) without any visual cues other than (a) suicide, or (b) starvation. Is there any electrical failure that can cause fuel valves to close? I dont fly Boeing, so can any Dreamliner driver explain what conditions could trigger an overspeed and auto engine shutdown (quote from Google below)? Would short runway, and hot/low QNH do it? Also, what happened to the order demanding a full power down/recycle every 51 days?

The EEC has build in protections to protect the engine. One of these protections is the Engine Overspeed Protection, when the core engine exceeds 120% the EEC shuts off the fuel to the applicable engine.

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.

SLF. I don\x92t know how B787 systems work but if that\x92s correct it must be a possibility. It seems as though engines are working fine until airborne. I\x92d just been asking elsewhere if it were possible that an electrical fault with the software could prevent both engines running? I know they don\x92t require outside power to continue to run, but if software was disrupted by a catastrophic electrical fault (issues reported on previous flight supposedly) would they shut down? But an error in the software could be more likely than the sort of failure requiring multiple backups to also fail I guess, and would also explain the timing of the engines shutting down/throttling back.

RIP to all the victims.

This is not completly correct. Pilots only depend on their gut feeling if acceleration is ok. There is no single measurement equipment on board that would precisely observe the acceleration rate. Which - to my mind - is somewhat a safety glitch. Not that I would say that this plays a role in this very accident.
I often contemplate when I rattle down the runway with 375 metric tons if I really hit V1 at the right place of the concrete strip. Although I learned how it feels when you stop with this weight at this very moment (engine failure with MTOM).

Hi everyone, 787 driver here, well lets look at the facts we see
very late rotation, but pitch and departure path look like normal up until stalling point.
mayday was called but without clarification or purpose, for me this indicates stress in the flight deck, especially low level
no smoke or fire from engines, I would rule out severe damage or birdstrikes at this point
Flaps 5 departure would be difficult to see as a pixel on a bad video, but they would not have made the rotation at that speed so I assume they used flaps during departure, also you would neglect to ECL's and a config warning
no RAT to be seen either, again ruling out dual engine failure, also the climb would not have been so parabolic
maybe single engine fuel starvation/Mechanical issue/dirty fuel, but seems unlikely, the flight path is too gentle
Gear stays down, and even though the pitch remains the same, they start losing lift and basically stall the aircraft into the ground
don't forget, Air India uses 64/67K engines on they're 787's, with temp of 41 degrees (ambient, so even more above tarmac) and a QNH of 1001, those engines will be pushed to "hard work mode" already

IMHO, two things I could assume happend
- either single engine failure, no pitch adjustment and speed fell below Vstall, OR, most likely
- mixup of Flaps moved to up position in stead of Gear moved to up position, that would clarify the gear, would clarify the loss of lift and that the engines have no smoke, and no RAT,

a few things stated as fact there without any evidence to support the assertions.

very late rotation - stated several times on this thread but zero evidence for it and some analysis suggests the rotation was at roughly the same location as previous departures of the same flight

no RAT - others, including one with a lot of experience with the sound of a deployed RAT, insist that it was deployed. The video evidence is unclear.

Not saying you\x92re necessarily wrong about anything but I take issue with those that state as fact things that are not (yet) supported by any evidence at all

Many GE engines - including GEnx-1B/67s - require microprocessors to be routinely replaced due to soldered joints failing after multiple cycles. There is a 2021 AD that notes "This AD was prompted by an in-service occurrence of loss of engine thrust control resulting in uncommanded high thrust" (I cannot post a link but google: 2021-25491 (86 FR 66447))

I am NOT suggesting that this specific failure mode happened here - for one thing, this would happen to one engine, not both. But on any flight it is possible that a unique set of sensor inputs to occur that are the first time any system has encountered them (example: NATS incident in 2023), and then you need failover & redundancy to keep things working.

The GE Aviation CCS system, which includes thrust management, has up to now flown for 1m flight hours without incident. It would be interesting to hear the perspectives of any engineers familiar with the system.

One has to assume that, given the seeming lack of lateral deviation from the flight path, and with no obvious yawing or rudder input visible on the videos, there's only two realistic conclusions here? Simultaneous dual engine failure of unknown cause if the RAT was indeed deployed; or flaps reduced too early leading to a stall if the RAT wasn't deployed.

Evidence in this thread would lean me toward the RAT deployed and therefore dual engine out scenario. As for the cause of that, well, only a couple of likely scenarios exist that could cause simultaneous shutdown of both engines, including mistaken or intentional use of the fuel cutoff levers.

I\x92d like to ask a legitimate question here regarding the runway footage.
there seems to be little to no change in aircraft attitude from point of lift off until just before impact.
I have no experience on commercial jets, so I am waiting to be corrected, but first thing in engine failure after take off is lower the nose? If RAT deployed they should have at least been able to do so?
The fact the attitude remains unchanged, would this not suggest they at least thought they had a chance of flying their way out of this situation?



im sure 787 is not prone to pitot/static blockage?

time will tell, until then we can only speculate I guess.

20+ years retired 777 Captain so not at all up to speed..
If you selected gear up but at that moment or just before there was a dual engine failure, would the gear move?
Just curious as to how things work.

Well of course they didn't understand what's going on. Something happened to them that has happened to a handful of people in history and is supposed to be essentially impossible. They didn't have the 'luxury' Sully had of a few thousand feet safety of altitude margin to think about it either.

Of course the didn't know why they'd lost power, they just knew they'd lost it. Yeh they would have felt pretty helpless 200 feet above the ground surrounded by tall buildings. My heart goes out to them being by that point no more than passengers to their own death. At least the actual passengers didn't have to watch the building coming at them knowing there was no escape. It's unthinkable.

So I don't know how on earth you think this suggests the flap theory. You're reading an awful lot into the words of a man who was likely processing the fact he's about to die in a horrific way.

Can we just forget about flaps? We have pictures of the wing at the crash site with flaps extended. The plane is on video with no engine noise and the RAT audible and visible. The pilot sent a mayday saying they'd lost thrust. The only survivor says the lights were flickering and the cabin went dark. Why are some people so desperate to pin this on a pilot mistake there is zero evidence for?

The visual evidence of the RAT being deployed (or not) is a bit dubious, but the audio evidence is pretty solid. It's also corroborated by the best eye witnesses we have, the pilots, explaining that they had lost power in their mayday call. And corroborated again by the second best eye witness we have, the passenger who survived, commenting on the 'green flickering lights' of the emergency exit signs indicating power loss. And corroborated again by the (now confirmed) posts on social media from the previous set of passengers complaining that aircon, entertainment, lights etc on the plain weren't working.

The idea that the flaps weren't set for take off also seems incredibly dubious given that in several frames of the original footage you can see the engines through the wings, on both sides, something not explainable by grainy footage or compression artifacts, and only possible if the flaps are down.

Edit to add: the reports on social media from the previous passengers complaining about non-functional electronics have been confirmed