Thanks, Kulverstukas.

I see the flaps are fully retracted on that wing, which cannot happen post the accident (presuming screw-jacks, like all other aircraft). So it is looking like early an inadvertent flap retract could be the problem.

:ok:, again, many thanks!

silverstrata, I noticed too, that they were retracted but that in itself is not, for the moment, evidence of anything other than "retracted flaps".

Collaborating evidence would be time-stamped slat/flap position, (both left & right, which may not be available parameters), airspeed, pitch, AoA & correlated CVR recording.

Kulverstukas do you have any information on the leading edge slats, such as flight deck location in relation to gear, flap and minimum speed for retraction. Any cockpit warnings/alerts for t/o without deployment. Are they linked to flap settings.

NOT T/O READY warning light and sound.

http://i053.radikal.ru/1612/23/9dc25e8a44a0.jpg

According to foreign news sources (interfax),combination of technical malfunction with pilot error led to inadequate lift to maintain flight is reported as the cause.

Not quite. On the CVR we have a "speed" call, and then a surprised exclamation about "flaps". I would say that is prima face evidence that there was something unusual or unexpected about the flaps. One possible unexpected flap condition is the flaps being retracted early, with insufficient speed. Another could be asymmetry, but most aircraft will lock automatically before an asymmetry develops.

Unexpected early flap retraction is the front runner, in my opinion. And it happens. As I relate above, there was a UK Io-co who had an acceleration call of "flaps up speed", which predictably resulted in a couple of inadvertent early flap retracts.

Thanks for the screw-jack image, Kulverstukas - that is an impressive array of hanging ironmongery. A most informative collection of pictures.

in my opinion the accidental flap instead of gear retraction alone does not explain it.

on the one hand it should be, even when it is of course bad airmanship and a dangerous situation , finally manageable by an experienced crew since the flaps and slats retract slowly while the reduced drag lets the plane acclerate quickly to its minimum clean speed. keep the nose slightly below stall angle, let the speed build up and then start to climb away. there were no obstacles ahead because they immediately were above the sea so no need to build up altitude at this moment .

on the other hand - even when not manageable - the "gear up" command comes shortly after liftoff and when the pilot instead of the gear lever operated the flap lever to "0" flaps resulting in a stall and crash it would have occoured in very close vivinity of the runway. i do not see a scenario where the plane struggels several miles out to the sea and even makes an u turn due to early flap retraction.

Excactly my experience and thoughts as well.
There has to be more or this accident would be off the end of the runway.

Even if the mods like to pull my comments. The two main gear pictures indicate that the main gear was retracted, especial the bent oleo on the first picture. It got a lot of load on impact, but asymmetrical as the oleos are not bent the same. The impact speed was quite high and the damaged oleos show that the impact was not flat but at a relative high angle of attack.

FDR or CVR recovered first?
 

I have a question.

Initially, it was reported that the FDR was recovered.

Then there were reports purporting to be flight deck conversations.

Only after the first of these appeared was it announced that a second recorder was even located.

Were the initial reports mistaken, and it was actually the CVR that was recovered first, or are all the flight deck transcripts actually fake news amplified by the internet echo chamber?

On the picture that Kulverstukas posted, there is a righthand maingear. It is interesting that first pair of wheels are torn off. Quite a force. Normally first pair of wheels hit the ground first, as gear is angled and they are lowest. Could these missing wheels indicate, that gear was not retracted, when plane hit water? First pair of wheels hit water, probably a wave, which at that speed is as hard as a concrete wall.
But then again, hydrocylinder is extended and bent, which means that gear was retracted during impact.
Here is a short video about how Tu-154 gear works:
https://www.youtube.com/watch?v=HhupJGUZYLQ

That's incorrect data. According Tu154 SOP in case of T/O with flaps 28:
- configuration change 28-15 - at speed 330-340 km/h
- from 15 to clean wing - at not less than 350 km/h
- 380-400 km/h (depending on weight) must be provided at the end of transition
So if they had 300 with clean wing.....

Are these data recalculated from Knots, or is the manual and SOP for Europe in SI units ?

It's actual data from SOP without any cut. I think it's hardly to find TU154B SOP in other language version than Russian

All USSR technical data is in metric units.

Looking into this one
Sergey Bainetov, the Russian Air Force's deputy head of flight safety
Minister of Transport, Maxim Sokolov

Latest press conference reports
https://sputniknews.com/trend/tu_154...cue_operation/

Also - sorry, but all talk of flaps may be premature - a single 'leak' and 'assumptions' in an echo chamber vacuum?

The following is all speculation.

If they had a slat and/or flap misconfiguration that resulted in a too high AOA they could wind up in a deep stall, those T-tails are prone to. It is mostly unrecoverable even at high altitudes.

http://www.aviationtoday.com/regions/ca/3011.html

Lots of folklore about T-tail deep stall to find on the web. The FDR data should give an answer about that armchair hypothesis soon.

Press-conference of Investigation Commitee

No explosion. Diversion or terrorism doesn't ruled out.

Time of flight ~ 70 sec, 10 sec of catastrophic situation.

Max height 250 m

Max speed 360-370 km/h

https://www.rt.com/news/372130-tu154...h-malfunction/