Posts by user "neila83" [Posts: 14 Total up-votes: 85 Pages: 1]

Originally Posted by Screamliner

maybe something we havent thought about, used the wrong zfw/tow, too much derate to make the departure, TO2 selected in stead of TO

Originally Posted by Sisiphos

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.

Originally Posted by smith

Just remembered this video of a787 with its RAT deployed. You can certainly hear it. A lot of people said you could hear it in the AI video but I couldn\x92t.

https://youtube.com/shorts/-mtK5el25...-GTp3OsDWnO6ex

Originally Posted by smith

The speculation that the pilot monitoring retracted the flaps instead of the gear is a valid one. There are a few incidents off the top of my head that I can think of. The BEA trident in Staines that stalled and crashed had had its droops retracted early, the Nepal ATR on approach, the PF called for flaps 30 and the PM pulled the props to feather and more recently when the BA 777 pilot at Gatwick pulled the power back instead of pulling on the yoke at Vr. As they say, if it can happen, it will happen.

Originally Posted by tumtiddle

Jump to 1:48 in this video (if the link doesn't automatically put you there): https://youtu.be/SbDJjgN7Xbo?si=ShNJ2oA39j46iw9M&t=108
You can't hear that RAT sound at the very beginning of the flypast?

Originally Posted by go-around flap 15

Why on earth would their speed increase if they inadvertantly retracted the flaps?! If flaps are inadvertantly selected up without the required airspeed, the nose would have to be raised to compensate for the loss of lift from the flaps in order to maintain a rate of climb/avoid a sink, which would have the secondary effect of reducing airspeed... It's genuinely frightening the level of technical knowledge on this forum.

Originally Posted by Tu.114

Here is another video.

https://www.youtube.com/watch?v=18BX9-Jeb5g

At 0:21 to 0:22, there appears to be an odd yellow flash around the #1 engine. This may of course also be due to the rather bad, filmed-off-a-screen video, but it occurs after liftoff and around a time when gear retraction would be appropriate.


https://www.youtube.com/watch?v=9Os8Xc-vsOw

Edit: here is another video showing the same scene in slightly better quality. The same flash is visible around 0:46.

This does not necessarily mean anything, of course, and it may as well be some reflection of the sun, but it appears to be about at the time a total power loss would have brought the known results.

Originally Posted by go-around flap 15

We're all shouting each other down with two main different theories on why the aircraft lost lift so shortly after takeoff.

1) Incorrect flap retraction causing the aircraft to lose lift and unable to recover the energy in time. (Not unheard of and plenty of reports where this has happened - albeit usually not to a crash).

2) Loss of engine thrust backed up two potential pieces of evidence that back up the RAT was deployed (apparent RAT sound, potential RAT seen on low res video).

It is impossible to know which of these is the case. Considering this summary of memory items is there the potential for a combination of both theories to have taken place?

Inadvertant flap retraction by PNF leading the PF to sense a sink and loss of lift. Pushes the thrust levers forward to the firewall and still the aircraft sinks. PF looking through the HUD and so very much 'outside focused' and doesn't realise that PNF has instead moved the flaps. PF defaults to memory items for loss of thrust on both engines before PNF can realise or communicate to PF what they've done, start switches are cut off which drops the RAT and from that point they're only heading one way. This would satisfy the strongly held belief that the RAT was extended, whilst also following the more likely initial cause of an action slip by PNF starting the sequence, rather than a dual engine failure.

Originally Posted by overstress

How do we \x91know\x92 that, exactly?

Originally Posted by nachtmusak

In the spirit of fairness there is another sensation that can be interpreted as "increased thrust" that a passenger is equally if not more likely to be talking about : a change in [perceived] engine noise level and/or quality.

Personally I don't hear much of the engines as the plane moves away from the cameraperson in the phone video, while the sound of impact is clearly discernible. If anyone can hear the engines well enough to tell if there is a significant change in their tone or volume, that would be valuable info, I think. Alternatively whatever increase in noise was heard started before the recording starts. In that case I suppose the "RAT theorists" would say it was the droning of the now-deployed RAT, with the assumption that it would be audible from inside the cabin (things like flap and landing gear actuation certainly are, so that isn't all that far-fetched). On the other hand, the "flap theorists" would probably say it was the crew firewalling the thrust levers in response to the inability to climb, which isn't far-fetched either.

Either way we will know soon enough what actions the pilots did or didn't take, since the various flight recorders should be found fairly easily in good condition.

Originally Posted by SpGo

Retracting the flaps would put them at the back of the power curve where drag increases with decreasing speed, causing the speed to reduce further!
The trouble seems to start at the exact moment the gear should have been raised, putting the flaps up, iso the gear, would cause the kind of loss of lift you see in the video. From there on, being at the back of the power curve, only firewalling the thrust levers and extending the flaps again could have saved them.

Originally Posted by Magplug

B787 Skipper.... No longer able to sit on my hands!

The joker that published one or other of the fictional accident reports before the dead are even identified needs stringing up by the thumbs.... Well done mods. OK, some of these theories, just bearing in mind the the flight recorder (there is only one FDR + CVR combined) was in the intact section of the undamaged tail and has been with the authorities for almost five days......

- All you guys who are rushing down the TCMA rabbit hole: If it was established that a software error drove both engines to idle without warning, after rotate.... Don't you think the worldwide fleet of B787s would have been grounded by now? Such a glaring failure would be absolutely inescapable on the FDR.

Whatever was wrong with this aircraft was present at rotate, unbeknown to the crew. The fact that no ADs or notices to operators have been issued usually means that the cause is known and the aircraft was serviceable. The statement from a prominent Indian Captain about the skill and tenacity of the crew, right up to the last minute is absolutely laudable. However, the cynic in me says that the way is being paved for some bad news and by that I mean news that will do Air India reputational damage. Expect more management of expectation in the coming days.

I'm still going with
a) Incorrect derate + low Vspeeds or
b) Low altitude capture

Originally Posted by MatthiasC172

Can someone help me with the calculations on how far from the point of our last ADS-B readout we can expect the stricken jet to fly/glide?

I am assuming the take off mass around 190-200 tons with 50 tons of fuel. For the glide phase this is of no importance, however.

Data on the Internet puts the glide ratio of a 789 around 18-21:1. Gear and flaps/slats out should have a significant negative effect. Does anyone have a good take how much? Minus 40%?

From the available data we can infer the plane never was higher than 200\x92 AAL, maybe even 100\x92. If I understood the online sources correctly, the point of impact was only about 20\x92 lower than the average runway level.

If I am not mistaken the distance from the last ADS-B point to the impact site is about 2 km as per Reuters and the Guardian. That would put it at 6,500\x92.

I just can\x92t get these numbers over each other without the aircraft producing thrust. Please help me correcting the numbers.

Originally Posted by Musician

You may be surprised to learn that aircraft sometimes need full thrust on the ground.
TCMA requires that the pilot pulls the thrust levers back to idle, and that the engine fails to spool down to idle as commanded. Only then will it shut off the engine (on the ground).
Pilots try to avoid pulling the thrust levers back to idle when they're taking off.
For that reason, TCMA has never triggered during take-off before.