Sorry if this was already posted.  Juan Brown's analysis.  

Basically, the sound of the RAT being deployed coiuld be heard, indicating a major hydraulics failure (at least).

He mentioned how it is hard to tell conclusively where flaps were given the grainy image.  

He's waiting for the data before jumping to conclusions.  

 

 

49 minutes ago, Ray Proudfoot said:

That sounds great until something goes wrong late into the takeoff roll and you don’t have enough runway left to safely stop. I cannot understand the logic of that procedure. It sounds pretty word not allowed dangerous.

The performance calculation will of course still generate an appropriate V1 speed , so there will always be enough runway to stop on provided the take off is rejected by V1, no change there.

2 minutes ago, jon b said:

The performance calculation will of course still generate an appropriate V1 speed , so there will always be enough runway to stop on provided the take off is rejected by V1, no change there.

But if the aircraft is designed to use the full runway does it continue to remain on the ground beyond Vr?

Sorry if I’m not fully understanding this Jon but seeing how late that 787-9 rotated makes me think it stayed on the ground beyond Vr.

7 minutes ago, kerosene31 said:

Basically, the sound of the RAT being deployed coiuld be heard, indicating a major hydraulics failure (at least

That’s one of the faults that deploys the RAT which will then provide hydraulic pressure to the centre hydraulic system to operate the primary flight controls.

So, in this case , providing the hydraulic fluid hadn’t been lost the flight controls will still work and the aircraft will be flyable, which isn’t what we saw. 
 

Because the aircraft stopped climbing and descended everything points to a loss of thrust, the aircraft sensing a dual engine failure will indeed also automatically deploy the RAT, that is what I believe we are seeing here.

I’m starting to form my own theory now on what’s gone on, but I’ll not make that public for now though.

4 minutes ago, Ray Proudfoot said:

But if the aircraft is designed to use the full runway does it continue to remain on the ground beyond Vr?

No, I’ve probably not explained it too well.

It’s my bed time and nothing puts me to sleep quicker than aircraft performance, so I won’t go into too much detail, but it uses what’s known as a balanced field length calculation to generate a balanced V1.

so there is sufficient speed and distance available at V1 to either stop in the remaining runway or to get airborne and climb to a height of 35ft by the end of the runway.

Have a look on YouTube or google for terms like “accelerate stop distance “  accelerate go distance” and “ balanced field length” that’ll get you off to sleep quickly!

By using all the runway what I was meaning is the aircraft could get airborne earlier using a higher flap setting and climb slower, however it’s designed instead to use a lower flap setting and accelerate longer on the ground before getting airborne and therefore have a better climb gradient and operate more efficiently.

What you may be seeing in the video clips, and I stress may, is the possibility an engine or engines were operating at reduced power, or one had failed (although no swing seen) after V1. In which case the aircraft performance calculations would have it clearing the end of the runway at just  35ft (minimum). During normal operations it would obviously be a lot higher , this is why perhaps it’s looking unusually close to the end of the runway when it rotates and kicking up the dust.

 

So that's 5 signs pointing to a dual engine failure:

1. High AoA descent into terrain.
2. Lack of engine sound in the video.
3. Deployed RAT in the video. (Visually seen and audibly heard).
4. The ATC call reporting loss of power. (Though it's not clear if that's electrical power or engine power).
5. The survivor reporting flickering lights preceding a bang, which is consistent with loss of powerplant generators and deployment of the RAT.

The question is what would cause both engines to lose power absent of a birdstrike? I know Jon has his theories, but does anyone else?

4 minutes ago, WestAir said:

So that's 5 signs pointing to a dual engine failure:

1. High AoA descent into terrain.
2. Lack of engine sound in the video.
3. Deployed RAT in the video. (Visually seen and audibly heard).
4. The ATC call reporting loss of power. (Though it's not clear if that's electrical power or engine power).
5. The survivor reporting flickering lights preceding a bang, which is consistent with loss of powerplant generators and deployment of the RAT.

The question is what would cause both engines to lose power absent of a birdstrike? I know Jon has his theories, but does anyone else?

wrong imput  into the fmc for reduced power take off, or  the auto thrust failed

There was one video from Captain Steeeve where a Delta plane taking off had to abort after getting halfway down the runway due to the right engine going bad.  In this situation, the pilots had time to react.  In the case of Air India,  do you think everything just went bad just after leaving the ground or was there a possibility that something happened just before reaching the end of the runway? 

Water Vapour....       from water in the fuel system .

The cloud of dust witnessed as the aircraft rotated....  is it dust ?   It looks  whitish and seems to be faintly coming from the left engine....

Is there a clue that this is  -  water vapour .... ?  (steam)

If the engines suddenly sucked in water from the fuel lines as the plane rotated then that water being injected into the extremely hot  (like a furnace)  turbine core instead of fuel would immediately flame out the engines and be evidenced by a large cloud of steam  (water vapour )  from the back of the engine ...  as witnessed.

Why did this not happen on takeoff roll...?   The tilting to the nose up attitude changed where the fuel was being drawn from and accumulated water lying under the fuel was then sucked in instead of fuel......

 

 

 

Yeah,  looks very much like  *WATER*  in the FUEL SYSTEM brought this plane down......

 

 

 

 

https://x.com/ShivAroor/status/1933165937399648447?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1933165937399648447|twgr^|twcon^s1_c10&ref_url=https%3A%2F%2Fwww.avsim.com%2Findex.php%3Fapp%3Dcoremodule%3Dsystemcontroller%3Dembedurl%3Dhttps%3A%2F%2Ftwitter.com%2Fi%2Fstatus%2F193316593739964844

 

 

 

Edited June 15, 2025Jun 15 by aerostar

I have a very difficult time reconciling (with the knowledge I have) why without a bird strike two engines would simultaneously fail. I am beginning to lean towards a potential autothrust issue... Now, I don't know what the 787 does, but on the 73, there is visible movement of the throttle up and down as the AT is doing its work. That does not happen on the Airbus. Is the 787 still following the Boeing logic or did that go with the Airbus one? Because I would think it would be much quicker to notice AT malfunction if you could see both throttles suddenly pull back to idle. If there is NOT a visual movement of the throttle, you need to watch the instruments, so considering there are just seconds for you to resolve what is going on, it could be that AT went idle for some unknown reason, they didn't notice it, or had no time to react? So that's one of the possibilities floating in my head. 

4 hours ago, aerostar said:

Water Vapour....       from water in the fuel system .

This or some other fuel contaminant is certainly plausible.

Jet engines are pretty much self contained eco systems, the only thing they require from the aircraft is a supply of fuel. Interrupt the fuel and it’s one of the few things I can think of that would cause a dual engine failure. Either the fuel is contaminated and gets into the engines or the fuel filters get blocked and starve the engines of fuel.

There’s various filter systems that should prevent water first reaching the aircraft tanks and secondly from reaching the engine in large quantities. Presumably other aircraft operating from that airport that would have reported fuel contamination so it remains puzzling.

The incorrect flap setting, wrong engine derate or auto throttle roll back all look unlikely to me. If there was insufficient lift or thrust the aircraft would either have not got airborne or climbed very slowly at a very shallow angle, not climbed to 600ft and the descended. And non of those would cause RAT deployment.

 

8 hours ago, aerostar said:

Water Vapour....       from water in the fuel system .

The cloud of dust witnessed as the aircraft rotated....  is it dust ?   It looks  whitish and seems to be faintly coming from the left engine....

Is there a clue that this is  -  water vapour .... ?  (steam)

If the engines suddenly sucked in water from the fuel lines as the plane rotated then that water being injected into the extremely hot  (like a furnace)  turbine core instead of fuel would immediately flame out the engines and be evidenced by a large cloud of steam  (water vapour )  from the back of the engine ...  as witnessed.

Why did this not happen on takeoff roll...?   The tilting to the nose up attitude changed where the fuel was being drawn from and accumulated water lying under the fuel was then sucked in instead of fuel......

 

 

 

Yeah,  looks very much like  *WATER*  in the FUEL SYSTEM brought this plane down......

 

 

 

 

https://x.com/ShivAroor/status/1933165937399648447?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1933165937399648447|twgr^|twcon^s1_c10&ref_url=https%3A%2F%2Fwww.avsim.com%2Findex.php%3Fapp%3Dcoremodule%3Dsystemcontroller%3Dembedurl%3Dhttps%3A%2F%2Ftwitter.com%2Fi%2Fstatus%2F193316593739964844

 

 

 

That is dust kicked up from the wingtip vortices at rotation. Pilots familiar with this airport have posted on PPRUNE that this often happens when wide bodies take off there, because the wing tips extend beyond the edge of the runway with larger aircraft.

While water can certainly be a fuel contaminant, it will collect at the lowest point in the tank due to being heavier than jet fuel. That is also the point where fuel is extracted from the tank by the pumps. If there was so much water in the fuel as to affect engine performance it would have manifested well before takeoff.

Old airliners like the original 707 actually used water injection ahead of the combustion chambers to increase takeoff thrust. It produces a dirty black smoke, not white steam.

1 hour ago, JRBarrett said:

That is dust kicked up from the wingtip vortices at rotation. Pilots familiar with this airport have posted on PPRUNE that this often happens when wide bodies take off there, because the wing tips extend beyond the edge of the runway with larger aircraft.

While water can certainly be a fuel contaminant, it will collect at the lowest point in the tank due to being heavier than jet fuel. That is also the point where fuel is extracted from the tank by the pumps. If there was so much water in the fuel as to affect engine performance it would have manifested well before takeoff.

Old airliners like the original 707 actually used water injection ahead of the combustion chambers to increase takeoff thrust. It produces a dirty black smoke, not white steam.

 

 

1 hour ago, JRBarrett said:

affect engine performance it would have manifested well before takeoff.

The aircraft took longer than normal to rotate according to airport personnel report...

The aircraft rudder was being input left,   as if loss of thrust to right engine on takeoff run.. hard to tell with the video quality but does seem to be.  There was a 4 knot crosswind right to left across nose,  rudder should have been right input if any.

The aircraft did not reach  V2 + 15 knots  at any time, which was  calculated at around 184knots (need verified)  Did the aircraft reach proper VR speed.....  in that case?

If the aircraft was carrying bunker fuel then it would be at close to max TakeOff weight...

If when the plane was level on the runway fuel was being sucked into the pumps.... then there would possibly be no sign of any problem,   until rotation, when the pump suction pipe would then be angled  in the fuel/water....  (or rather the liquid level would be angled to the pipe) and then start drawing water instead of fuel.. from the accumulated water level lying under the fuel.

 

 

1 hour ago, JRBarrett said:

ahead of the combustion chambers to increase takeoff thrust. It produces a dirty black smoke, not white steam.

The water was being injected along with the dirty burning fuel  ...  any sign of steam would be lost in the fuel smoke in that case.

Fuel was not being injected along with the water in this case.. pure water....   no dirty black smoke.  In fact no flame after a few seconds just cold steel...

 

------------------------------------

 

If the aircraft was carrying bunker fuel (ie: Full fuel tanks) then the high additional perrcentage of water added to tanks that may already have water in them could possibly raise the water in the bottom of the tanks to the level of the fuel pump suction pipe....

 

PS - on the subject of dust...  how could we ascertain if this is dust , vapour, a mixture or something else...

I have tried to find a video of a 787 8 taking off under similar conditions to have a compare.....

... anyone help ?

 

 

 

 

Edited June 15, 2025Jun 15 by aerostar

Among the many videos online of take-offs made by 787-8s, I have not seen "anyone" using the entire runway before taking off.

It is the software that for take-offs, after entering the data into the FMC, calculates the speeds V1 and VR and the pilots must comply with this procedure which also requires that, "within V1", there is a length of the runway remaining sufficient to stop the plane in the event of a failure.

It is the length of the runway that determines whether the take-off of an aircraft can take place regularly in safety to comply with the procedures and regulations in force to the point that if the length of the runway does not guarantee this, in many airports you do not see planes that need longer runways to land/take off and it makes no sense to use the entire runway before taking off to have more speed than VR, considering the danger of obstacles or houses near the runways such as, for example, at VAAH.

Among the many videos on the 787-8 I chose this one that shows what happens from the pre-flight briefing to the configuration of the flight in the cockpit and the take-off.

This TUI flight between EHAM and TNCM has some similarities with the tragic VAAH and EGKK because the distances of the flights are about 7,000 km for both and the length of the runways used at EHAM (the 24) and the one at VAAH are both about 11,400 feet.

From the pre-flight briefing, the pax are 255 +8 crew, total 263. After a discussion, it is decided that the fuel for the flight will be 55 tons.

The total weight of the aircraft at take-off (aircraft + pax + crew + cargo + fuel) is 201 tons.

Subsequently, on the FMC Take off page, it reads: Flap at 5, V1 155 and VR 158.

During the cockpit configuration, the Captain asks the first officer what are the possible failures "within V1" that will have to interrupt the take-off.

Also on this video you can see that, after V1, the rotation occurs well before the end of the runway while you can see at what height the plane reaches the end of the runway which should have also happened at VAAH.