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-   -   TU154 out of Sochi is missing. (https://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing.html)

Kulverstukas 6th Jan 2017 14:43

BTW
max gears - 400 kmh
max HS stab move - 425 kmh
same for max slats
max lights - 340 kmh

APU
max height 4000m
max start height 3000m
Vmax - 525 kmh

aerobat77 6th Jan 2017 14:50

the indicated airspeed indicator is left of the attitude indicator showing 200-1000 kmh (2-10) , both pilots and the flight engineer are equipped wirh this. remember all is metric . so e.g "5" on the vertical speed indicator ist not 500 ft/min but 5 meters / second .

Kulverstukas 8th Jan 2017 10:32

http://s61.radikal.ru/i174/1701/3d/5d9aba7697da.jpg

http://s018.radikal.ru/i506/1701/11/9f0b3270812b.jpg

Machinbird 8th Jan 2017 15:58

Thank you for posting the wing picture Kulverstukas.
Trailing edge flaps up.
Leading edge flaps mostly torn off although there is a section of the leading edge profile present.

Is that a fixed LE section or is it a section of LE flap that might have been held in place by an actuator? Anyone know?:confused:

guadaMB 8th Jan 2017 16:21

Looking into the pics reciently uploaded by Mr. Kulverstukas appears a new CERTAIN data:

THE AC DIDN'T IMPACT IN A STALL POSE.

Machinbird 8th Jan 2017 16:41

guadaMB, can you explain your reasoning?

In general, the entire aircraft is not going to enter the water at the same time, and depending on sink rate, the first part to enter the water (generally the tail) can impose sufficient force on the reminder of the airframe to significantly change its attitude or actually break off the contacting portion from the rest of the airframe.

My initial guess from looking at the wing wreckage is that the aircraft impacted upright with the wings being nearly wings level, and again, only a guess based on the damage that the fuel load did to the wing structure.

klintE 8th Jan 2017 16:57

I don't think there is a such thing as "stall pose" at impact
Stalled a/c can get into a spin, flat spin or can just mushing down in horizontal position (like AF447). And impact attitude for each case could be different.

Chronus 8th Jan 2017 18:38

The photo of what appears to be a section of the port wing shows a fairly uniform separation of its bottom midsection together with all its leading edge slats. I understand fuel tanks are carried in the wings. Assuming this to be the case, I would suggest that the damage exhibited is resultant from a fuel tank separation and ejection from the wing taking with it all the leading edge high lift structures. Such scenario would involve high speed and large deceleration forces. The outward bending of outer wing skin panels are possibly caused by hydrodynamic forces entering the wing box following the ejection of the fuel tank. All suggesting a fairly laterally level trajectory high speed collision with the surface of the water.

Kulverstukas 8th Jan 2017 18:43

There is no "fuel tanks", wing itself is filled with kerosene. This pink stuff you can see inside is hermetic cover.

Machinbird 8th Jan 2017 19:06


The photo of what appears to be a section of the port wing
That has to be the starboard wing. Look how the stringers decrease in quantity toward the left of the top side image.

Chronus 8th Jan 2017 19:12

I was going by the part of a letter, which may be "C " visible on the photo. But I think you may be correct.

Kulverstukas 8th Jan 2017 19:15


Originally Posted by Chronus (Post 9634334)
I was going by the part of a letter, which may be "C " visible on the photo. But I think you may be correct.

http://s019.radikal.ru/i634/1701/f5/5d089db6e1d7.jpg

It starboard wing laying top up, leading edge first. The same one seen on the night photo lifted from water and turned bottom surface to us.

More photos of the wing:

Wingtip

http://s19.radikal.ru/i192/1701/ae/bd68667f304f.jpg

Close view

http://s018.radikal.ru/i504/1701/a5/4b6a311b4e4c.jpg

Chronus 8th Jan 2017 19:33


Originally Posted by Kulverstukas (Post 9634305)
There is no "fuel tanks", wing itself is filled with kerosene. This pink stuff you can see inside is hermetic cover.

Thank you Kulverstukas. So it`s got wet wings, nevertheless it would still be housed in a box structure within the top and bottom outer wings skins. As can be seen on the photo the bottom skin panels are gone. This suggests the vector of forces acting must have been forward of the bottom of the wing, but at a fairly large angle of attack. I believe the result would still remain the same. Fuel would act as a ram in its continuing forward travel whilst the wing has rapidly decelerated.

TURIN 8th Jan 2017 19:48

Sorry to digress, but "wet wings"?

In 35 years working around aeroplanes I have never heard this expression before. Just curious where it comes from.

If you mean "integral fuel tanks" then standard construction of a wing is a front and rear main spar with ribs between the two and upper & lower skin to create the fuel void. Depending on type the void may have baffles between the ribs or the ribs act as baffles to stop the fuel sloshing around and acting as a 'ram'.

Hope this helps. :ok:

guadaMB 8th Jan 2017 20:15

@Machinbird and @klintE

An AC crash impact in a "stall pose" means TAIL FIRST (as a tail strike in TO or landing).
This is "in the moment of impact".
IF an AC begins a stall -say at FL300- and THEN it spins or flat spin or whatever makes and the impact is in another position, then it isn't a crash in "stall pose".

In this case, being for the action of the load of fuel, being for the contact with water, it's clear the wings touched waters FRONTALLY, flaps retracted. This could be a "nose first" crash with some lateral inclination. This because damage in wings aren't equal. One shows a frontal impact and the other as if touched water (hard as stone) more paralel to the surface.

DaveReidUK 8th Jan 2017 20:28


Originally Posted by TURIN (Post 9634367)
Sorry to digress, but "wet wings"?

In 35 years working around aeroplanes I have never heard this expression before. Just curious where it comes from.

If you mean "integral fuel tanks" then standard construction of a wing is a front and rear main spar with ribs between the two and upper & lower skin to create the fuel void. Depending on type the void may have baffles between the ribs or the ribs act as baffles to stop the fuel sloshing around and acting as a 'ram'.

It's pretty common usage, in my experience (which includes crawling inside them).

Even Wikipedia manages a defiinition:

"A wet wing is an aerospace engineering technique where an aircraft's wing structure is sealed and used as a fuel tank. Wet wings are also called integral fuel tanks."

lomapaseo 8th Jan 2017 20:30


An AC crash impact in a "stall pose" means TAIL FIRST (as a tail strike in TO or landing).
This is "in the moment of impact".
IF an AC begins a stall -say at FL300- and THEN it spins or flat spin or whatever makes and the impact is in another position, then it isn't a crash in "stall pose".
Now i'm getting confused. I'll admit that I have read the words "wet wing" but I have never read the words "stall pose" in an accident description.

Are you saying that even though the pilot couldn't lift the nose using aerodynamic controls as it flew into the ground that it wasn't stalled at the time because the nose was pointing down?

guadaMB 8th Jan 2017 21:07

Yes, sir.

I THINK the AC went down nose first. Or almost.
I'm not a fortune teller, but worked in SAR all of my life and the damage showed in the wings pics say (to me) the AC dived in the sense of movement, nose first.
Unfortunately we haven't more data (i.e. the cockpit section, which is TOO strong in the Tu-154) but the flaps 100% retracted and the short time of flight tell me the PiC couldn't do much to keep the bird in a rather normal order of aviate.
I suppose that in SECONDS (because the bird was seconds airborne) the commander and FO could do little to correct the possible mistakes (if were mistakes, of course). I don't discard a technical failure, but those flaps...

guadaMB 8th Jan 2017 21:20

ABOUT FLAPS:

AFAIK, the flaps selection (in the whole calculations for TO procedure) in this bird is very variable, depending -mainly- on weight, runway lenght, wind, temperature and other parameters.
It would be good if anybody could tell specific experience and opinion about this subject and if it's POSSIBLE the crew had selected FLAPS 15 in this TO.
Provided flaps were deployed, it's almost impossible to have selected 30º and crashed in a matter of seconds after TO with flaps 0º...

TURIN 8th Jan 2017 21:28

DaveReid, thanks, everyday is a school day. I shall add it to my repertoire.:ok:


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