TU154 out of Sochi is missing. [Archive] - Page 2

guadaMB

2nd Jan 2017, 17:41

Yesterday, arriving in Barajas Airport (MAD) met a Russian old friend, pilot now retired.
Taking a coffee, asked him about his glances in the TU-154 crash out of Sochi.
Besides he was an IL (Ilushin) specialist, he's been formed in Soviet (jet-era) air-industry so he's used to the construction philosophy that aimed those decades (mainly the 60s and 70s).
First, he's been very DIRECT on one subject: that is very "complicated" to misconfigure a Russian old bird for the TO protocol. He insisted on this: there are lots of procedures, one linked to the other that makes a couple of professionals make a stound mistake of fatal consequences almost impossible.
And added: "take a look at some crash record of Russian ACs and see how many crashed on TOs and how many the further investigation determined it was caused by an erroneous configuration for TO".
BTW: TU-154 is NOT my favourite plane to fly -as passenger, I mean- but have to admit it looks elegant and strong in its rather "old" lines.
So I took some time to investigate about TU-154 stats.
Registered out of the production line are +/- 1030 units during the almost 40 years of prod.
Is one of the fastest civilian jets ever made (up to 990 km/h at cruise level)
Important accidents involving this AC: +/- 30.
This meaning: the qualifying as "accident" vary with interpretations.
First conclusion: it's a very safe bird, with a rate of -3 to -4 %, which is NOT BAD. Same safety figures shared with European and American ACs.:ok:

Now come some interesting details.
- I've found ONLY ONE accident developed in TO procedure. Was due to possible windshear & thermal currents which led to an early stall in an extremely hot environment (Aeroflot 4225).
- One went down due to RADAR FAILURE.
- ONE after ATC went asleep and pilot didn't know there were maintenance vehicles on the runway.
- One after a severe ENGINE FIRE.
- One on approach due to cargo overweight and further disbalance.
- One hijacked andc then "shot-up-to-swisscheese" after a "regular" landing.
- One that stalled at FL380, followed by bad crew operations due to a very scarce instruction by the builder/airline (Aeroflot 7425)
- One on approach, found severe winshear and failed the horizontal stabilizer.
- One with a severe electrical failure (no crash, no injuries).
- One after TO (yes, but...) the crew IGNORED warning ligths telling problems to eng #2 believing the SYSTEM WAS WORKING BADLY and decided to take-off. Period.:=
- One run out of fuel. Crashed in bad-foggy weather in Libya.
- One "in flight" due to a FIRE in the tail section followed by a lack of control.
- One (another) during TO, but... This is Cubana de Aviación, Flight 389 from Quito to Guayaquil. After TWO rejected TOs, the stone-headed PiC decided for a third intent in which the crew FORGOT to select the hydraulic valves switches, with the result of a failed TO, runway excursion and a general disaster in a close to the airport neigbourhood. Avoidable and :ugh:
- One crashing during approach, possible bad maintenance of the whole AC.
- One "in flight" due to AP malfunction after a sequence of strong vibrations during more than 15 minutes.
- One in flight with no causes found.
- One down after an unrecoverable spiral while in cruise at FL380.
- One that caught FIRE before TO (only two dead of a total of 160)
- One possibly gunned close to Lebanon coast.
- One made a bad approach under extreme Wx conditions (Polish AF plane near Smolensk).
- One that supposedly was flying above recommended cruise-ceiling, had a stall, then a flat spin. Possible crew overlooked the controls of the AC.
- One down after a blast (explosives, intentional) on board.
- One shot down by a military S-200 (Ukraine).
- One "destroyed" on landing. Had a strong tail strike but were no injuries, no dead.
- One deployed very bad approach procedures with the following crash. No survivors.
- One stalled fatally on approach.
- One crashed on a mountain top after a sequence of crew's small navigation errors.
- One crashed after TWO ENGINES failed after TO, then the THIRD. Possibly bird ingestion by fans.
- TWO TU-154s went down after MID-AIR collisions.
.......

And now we come back to present: my Russian friend told me that's not very understandable that a professional and experienced military pilot and his FO (supposedly also experienced and skilled enough to co-fly this bird) make a BAD CONFIGURATION FOR TAKE OFF in a Tu-154.
Asked if was a possibility the mentioned confusion of levers (flaps/gear), he doubted energically.

MrSnuggles

2nd Jan 2017, 18:18

All of this talk about lever confusion...

I googled "tu 154 cockpit" and found the following. Images are too large to insert here I think, so I'll link them instead. Maybe someone wants to educate the plebs about what lever is where...

Slovak Gouvernment Tu154M OM-BYO interior, modernised:
http://www.airlinereporter.com/wp-content/uploads/2014/05/IMG_7488-2.jpg

Photograph from Aleksandr Markin of a Tu154M, featured on Wikipedia:
https://www.flickr.com/photos/33104187@N04/3926436610/sizes/o/
https://upload.wikimedia.org/wikipedia/commons/1/12/TU-154m._Cockpit._(3926436610).jpg

Here is also a video from a Tu154M takeoff in 1991 operated by Malev. Various levers can be seen at 0:28:
https://www.youtube.com/watch?v=1izgC0FMHiw

Kulverstukas

2nd Jan 2017, 18:36

what lever is where...

Flaps: overhead panel, center
Gears: overhead panel, right hand.

http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-7.html#post9621956

https://img-fotki.yandex.ru/get/172017/6154164.29e/0_bb224_a970fc6f_XL.jpg

up_down_n_out

2nd Jan 2017, 18:36

Excellent post, thank you.
It was almost exactly what I previously said, "something doesn't add up".

I think I flew on that Malev a/c in 1988 from CDG.
It was the 1st time on a TU154B,- quite unforgettable.

With respect, you omitted the various accidents with the TU134,which is an extremely similar a/c albeit with only 2 engines, somewhat smaller, but also good safety record.

The most recent disasters which stick in the mind,

UTAir flight 471 Samara, landed 400m short of runway, failed to communicate/compensate for poor weather+ATC failures, 6 killed.
Pilot error

20 June 2011 Flight 9605, Petrozavodsk - CFIT landing. 47 dead. - ?mistook road for runway.
Pilot error

28 December 2011 OSH hard landing (over 2.5G!).
Crew not competent.

Kulverstukas

2nd Jan 2017, 18:42

you omitted the various accidents with the TU134,which is an extremely similar a/c albeit with only 2 engines

Tu-134 was ancestor of Tu-104 which was Tu-16 converted into passenger jet. Tu-154 was designed from scratch.

guadaMB

2nd Jan 2017, 19:29

"With respect, you omitted the various accidents with the TU134,which is an extremely similar a/c albeit with only 2 engines, somewhat smaller, but also good safety record."

When made the list of Tu-154 crashes selected the most "significant", just to make it readable-non-bothering. And to remark the almost nil presence of "immediate-to-TO" crashes.
And the stats ARE about Tu-154. If I had to add "precursors" and "similars", list would be endless.
As far as I remember, Tu-154 wasn't a follower of any type.
It was drawn from the beginning after a B-727 "inspiration", but from zero... There are many tales about some blue-prints that went from Seattle to Basmanny...:p

And, BTW, the accidents you mention (3), AREN'T during TO procedures.

I agree with you. It's difficult to make a configuration mistake in a so "analogic" AC.
Time and investigation will tell us...

Chris Scott

2nd Jan 2017, 21:10

Hi Kulverstukas,
Did you mean to say that the Tu-104 was an ancestor of the Tu-134? But they seem to a casual observer like me to have little in common.

Thanks for the drawing of the Tu-154 centre-overhead panel to back up the photo in post #128. Here's the link again, as we're on yet another page:
http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-7.html#post9621956

The gear and slat/flap selector levers, in addition to being in a position unfamiliar to crews of western jet-types, are smaller. But they are well apart and look (and feel, presumably) different from one another. Any crew mis-selection would involve either total lack of familiarity, or extreme fatigue.

One feature of the gear selector is that, like many 1950s and 1960s types, it has a neutral position (centre): probably to de-pressurise the up lines after gear retraction. (On later types, this is done automatically.)

Where are the gear-position lights/indicators?

A graphic I found on the X-PlaneReviews website by Felis Planes appears to show the slats/flaps position-indicator at the forward end of the centre pedestal, visible to both pilots:
http://xplanereviews.com/uploads/monthly_2016_05/574cddc35fab0_tu154_Panel4.jpg.466336a9da95a7f00e0087bcc0e69 f55.jpg

Kulverstukas

2nd Jan 2017, 21:57

Did you mean to say that the Tu-104 was an ancestor of the Tu-134? But they seem to a casual observer like me to have little in common.

Tu-16 -> Tu-104 -> Tu-124 -> Tu-134

Where are the gear-position lights/indicators?

Top right of the middle pilot panel, next to it is flaps indication.

http://russianplanes.net/images/to173000/172175.jpg

Kulverstukas

2nd Jan 2017, 22:10

http://russianplanes.net/images/to12000/011758.jpg

Chris Scott

2nd Jan 2017, 22:17

Thanks, Kulverstukas, that is in roughly the same position as most types with which I'm familiar. But the surprise is the fact that the selector is not located where might be expected: below the indicator lights. (Great photos, BTW.)

On the possibility of fatigue-related error in selection, not detected immediately by the rest of the crew: to state the obvious, 4 a.m. is a particularly bad time of day.

aerobat77

2nd Jan 2017, 23:54

andrasz

3rd Jan 2017, 05:47

in my opinion this is not and simply cannot be the reason...

Completely agree. However there is one more mental trap that could hav been the case:
If they were taking off with Flaps 15 due to the relatively light load, but the mental picture of the PF was Flaps 28 (the more common setting), retracting flaps one stop would have an entirely different outcome due to the huge speed gap between 15 and 0.

DaveReidUK

3rd Jan 2017, 06:29

how does the plane continue out to the sea and even makes an u turn back before crashing

Correct me if I'm wrong, but the location of the wreckage relative to the runway suggests that it didn't.

Chris Scott

3rd Jan 2017, 09:45

Even if the aircraft was airborne for the entire 70 seconds quoted, which is unlikely, it could not have completed a u-turn in such a short time.

HansBerlin

3rd Jan 2017, 10:50

but again for those who assume that the copilot simply selected flaps up instead of gear up as the reason of the crash : how does the plane continue out to the sea and even makes an u turn back before crashing in a scenario of "positive rate, gear up ( but instead of this flaps up ) " . common sense dictates that they would crash at the end of the runway. in my opinion this is not and simply cannot be the reason.

Assuming a long take off roll (heavy plane per pilot), flaps up instead of gear up 3-4 seconds after lift off -- wouldn't the remaining flight time/crash location be consistent with the time it takes to retract the flaps?

aerobat77

3rd Jan 2017, 11:58

Snyggapa

3rd Jan 2017, 12:11

Would it be a clean configuration though - in this scenario the gear would still be down.

aerobat77

3rd Jan 2017, 12:29

well , in the scenario there was nothing wrong with the aircraft beyond wrong lever operated by fo i bet the tu154 has more than enough power to climb away from minimum clean speed even with the gear still down.

and again : when the current info is correct he made it to minimum clean speed !

andrasz

3rd Jan 2017, 12:30

Someone more current please correct me if I'm wrong, but according to my memory of many jump-seat rides in TU5 with 3 crew cockpit it is the PF who selects the flaps on callout from PM (speed check), with the FE adjusting throttles on verbal command (PF only handles throttles on final approach). The flap lever can only be moved one stop by compressing the two side clamps, another stop requires a release of the hold and compressing the clamps again.

I see mentally confusing original flap setting and believing to move the lever from 28 to 15 while in reality it was from 15 to 0 a plausible scenario. In either case, were it flaps instead of gear, the FDR will tell as gear/flap position parameters are recorded.

guadaMB

3rd Jan 2017, 14:32

I always dislike to make guesses, but...

Looking into this video:

https://www.youtube.com/watch?v=8qTiR7hraf0

We can see the FLAPS CONFIG IS CLEARLY 15º for the entire TO procedure, the AC does all correctly and arrives into destiny airport (Minsk) in perfect shape.
Gear is retracted about 6 secs after being airborne and 15º flaps are retracted to 0º about 115 secs later.

If this AC can TO with this configuration, why not the Sochi one?
So why many say a 28º (then retract to 15º) was the "regular config"?

There is a certain data: FLAPS WERE RETRACTED when crashed after a clear photo of a wing taken when washed off from Black Sea waters.
If there was an order of flaps-up, provided they were settled 15º, the only possible next position was ZERO DEGREES.

And now, what about the confusion of levers or its sequency (which I see too difficult for an experienced crew)?

There is the slight possibility of a confusion (flaps-up instead of gear-up first), but the TU-154 is a very powerful bird. If it reached +/- 300 km/h at about 250 m (800 feet), even with the gear DOWN and FLAPS 0º would push-up with no problem until things were cleared and the cockpit people calmed enough to settle things to "regular".
As far as I know, throttles on a TU-154 are FE (flight engeneer) commanded. They're not a responsibility of the two in command, so it's very difficult to think in a loss of thrust due to a "cockpit mess".

And also confusing is the RIGHT TURN. If the AC is doing nonsense (whatever the reason) why the hell any PiC would like to make a turn in such a conflictive scenario? This puzzles me...:rolleyes:

HansBerlin

3rd Jan 2017, 15:25

Kulverstukas

3rd Jan 2017, 15:26

And also confusing is the RIGHT TURN. If the AC is doing nonsense (whatever the reason) why the hell any PiC would like to make a turn in such a conflictive scenario?

There is no evidence of right turn except poorly drawn draft of a/c route, presented at the first press-conference, when rescue operation just started.

Hotel Tango

3rd Jan 2017, 15:48

There is no evidence of right turn except poorly drawn draft of a/c route, presented at the first press-conference, when rescue operation just started.

More to the point, planned route, based on the SID (I presume).

Pali

3rd Jan 2017, 16:28

well , we can only discuss currently available data but when only the published speed of 350-360 kmh is correct the flaps up theory as only reason cannot be valid.

why ? because when he was able to reach 360 kmh with a fully functioning aircraft and all engines developing rated thrust he would get away with this even when the fo selected flaps up since 360 kmh starts to be sufficient to stay airborne even in clean configuration. so this accident would never happen but it happened.

there is surely more in this than the fo grabs the wrong lever after takeoff.

If flaps were retracted too soon and a/c lost lift it may be that they reached 350kmh nose down but it was not enough to arrest descent before hitting sea surface. Out of height, out of options. But the poor souls were maybe closer to salvation than we may think.

guadaMB

3rd Jan 2017, 17:11

There is no evidence of right turn except poorly drawn draft of a/c route, presented at the first press-conference, when rescue operation just started.
Oooppsss...
I thought it was something confirmed.
Sorry to include it in my guesses...

If flaps were retracted too soon and a/c lost lift it may be that they reached 350kmh nose down but it was not enough to arrest descent before hitting sea surface. Out of height, out of options. But the poor souls were maybe closer to salvation than we may think.

This could happen if things went "the simpler of mistakes the bigger the problem".
The AC took off with flaps 15º, once airborne PiC commanded "gear up" and the FO made THE mistake: flaps up.
Normally the retraction of gears is in the region of 5 to 8 seconds after being airborne.
As far as I could chronometre, flaps from 15º to 0º take 18 secs.
It's VERY possible all in the 70 seconds (is this timing confirmed, Mr. Kulverstukas?) because once the flaps retraction begins, also begins the lack of lift, in geometrical progression, hitting waters at 300+ km/h and destroying the AC.

Kulverstukas

3rd Jan 2017, 17:19

is this timing confirmed

70 second and "10 second of catastrophic event unfolding" are from official press conference after CVR/FDR readout, but not clear what this 70 sec are counted from.

aerobat77

3rd Jan 2017, 18:37

we will see and come back to this gents, but i do not think so - it was not nose down but up till the stall angle , i think he had some massive drag either by speed brakes / spoilers extended , a reverser unlocked or he had lack of power by the engines. the flaps were put up intentionally as soon as possible to reduce drag and he aimed for minimum clean speed , the words "damn flaps" was either false translation and he meant spoilers or a last desperate word when he realized he is down to a speed he will stall for sure without flaps.

raising flaps immediately after takeoff will result in an crash very close to the airfield or a none event , depending on the mass, crew action , power of the engines and the design how critical the wing is.

i would not blame the fo he grabbed the false lever because i,m sure its not the cause.

Chris Scott

3rd Jan 2017, 18:47

Quote from aerobat77:
"raising flaps immediately after takeoff will result in an crash very close to the airfield or a none event "

Sadly, the aircraft did indeed come down close to the airfield. Flaps and slats do not retract instantly.

Fortunately for the investigators, loss of thrust or any other fault leading to loss of performance (other than structural failure) should be recorded. A severe nocturnal tailwind-sheer seems improbable, but if applicable could also be inferred from the flight data.

BluSdUp

3rd Jan 2017, 20:56

Were they both captains on such an VIP flight.?
Experienced, but not lately? and NOT from right hand seat?
Anyway, never seen anyone ever do the flaps before gear, but this fits the profile perfect as we know it.
How:, Cpt in f/o seat , not instructor or used to fly from that side.
Nearest Flaps
Far lever, Gear,
ooops.
Gear and Flaps retracted in wrong sequence, not flyable, end story.
Unlikely, but simple,
And with a normal gear flaps sequence they would hit 2 miles and not 1 mile after liftoff if somthing else happened just at flaps up.
Hit me ,
May their music live on.
Cpt B

twb3

3rd Jan 2017, 21:13

Is there any indication that there may have been a split flap condition on retraction? Is a split flap malfunction plausible on this type aircraft?

TWB

BluSdUp

3rd Jan 2017, 21:43

We have next to no info, but flap asymmetry is a non event as far as control is concerned . On Boeing it locks with a diff of .4deg. no roll even. No cure.
Yes all aircraft can have it, and all are protected.
Complete flap assym not likely.

WBryanH

4th Jan 2017, 05:24

Originally Posted by guadaMB http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-13.html#post9627745

not very understandable that a professional and experienced military pilot and his FO (supposedly also experienced and skilled enough to co-fly this bird) make a BAD CONFIGURATION FOR TAKE OFF in a Tu-154.
Asked if was a possibility the mentioned confusion of levers (flaps/gear), he doubted energically.

guadaMB, thanks much for your list in your 2 Jan post. I wondered too how rare flaps/slats/gear errors on TO. Seems very rare indeed.

I also worked up that list. I spreadsheeted Tu-154 incidences from ASN:

https://aviation-safety.net/database/types/Tupolev-154/database

It gives 118 incidences total out of 1026 Tu-154 produced, 69 hull losses. Hull losses come to under 7%, comparable to the 727. Only 20 of these losses occurred during TO (14) and Init Climbout (6). Most of the TO probs due to overloaded planes with shifting cargo, and engine fails. Not clear if ANY due to flaps/slats/gear errors. Could be, some of these notes clearly not complete. Only one clearly tied to control surfaces, deployed spoilers on CCCP-85030 in 1973.

guadaMB

4th Jan 2017, 08:15

At 195 kts it would normally have kept flying much longer (or to its destination) even with the flaps taken in by then. But it seems to have fallen like a rock when the flaps were brought to zero.
We can't discard a bit of confusion inside cockpit once the problems begun.
And this is fatal within seconds under these (supposed) conditions.

klintE

4th Jan 2017, 12:42

Last words from CVR (We are falling, sir) in explicit way suggest loss of control. However, it still could be from many reasons like stall, upset, structural failure, etc. We know nothing at the moment about critical event.

And, IMO, its very unlikely that they retracted flaps instead of landing gear just after airborne.
Should be an audible alarm noticed then. But it wasn't.
And finally, Head of the russian FAA said clearly that except last 10 seconds everything was pretty normal in that flight.

DaveReidUK

4th Jan 2017, 14:44

Important accidents involving this AC: +/- 30.
This meaning: the qualifying as "accident" vary with interpretations.

ICAO Annex 13 defines what is and isn't classified as an accident.

There is very little scope for "interpretation".

WHBM

4th Jan 2017, 15:24

For those describing the Tu154's considerable power/weight ratio, bear in mind this was a Tu154B with the original Kuznetsov engines, rather than the later Tu154M variant, the only one in airline use for the last 15 years or so, with substantially improved Soloviev engines, which much recent documentation refers to.

If we take the inadvertent flap retraction line, there is of course a timelag between selection of retract and the achievement of that, which does vary from airframe to airframe dependent on the state of the hydraulics. When first selected the aircraft would still be accelerating, until the progressive loss of lift overcame the speed.

I can believe the FO still thought they had retracted the gear, and the commander was too absorbed with maintaining flying into unexpected conditions to scan all the controls. I wonder what the FE was doing during this time; are gear and flap indicators repeated on their panel ?

peekay4

4th Jan 2017, 15:40

ICAO Annex 13 defines what is and isn't classified as an accident.

There is very little scope for "interpretation".
Well, that's not completely true. Many organizations have their own definitions of what is / isn't classified as an accident, although ICAO definitions tend to be used as a starting point.

Most notably, in the airline industry much of our safety statistics are based on IATA definitions, which are more restrictive than the ICAO definitions. I.e., many events categorized as accidents by ICAO are excluded from IATA's definition.

Hence ICAO accident statistics can't be compared directly with IATA statistics. The Global Safety Information Exchange (GSIE) was created in part to facilitate exchange of data between the two organizations.

Similarly many researchers (e.g., from Flight Safety Foundation) may use their own modifications of the basic ICAO definitions depending on the study -- usually because the ICAO statistics tend to be over-broad.

It's perfectly fine for guadaMB to include / exclude data for specific purposes as long as it's clear to everyone what were the intentions behind them.

Propduffer

4th Jan 2017, 15:52

bear in mind this was a Tu154B with the original Kuznetsov engines, rather than the later Tu154M variant
All the more reason to think the aircraft was overloaded. But until we find out basic things like the location where it impacted the water, and confirm what the highest airspeed / altitude obtained were, we are just gossiping about this crash.

I also don't put a lot of faith in the accuracy of the snippet of cockpit dialogue put out by RT news, if they're going to release anything, why not release the whole transcript? What's the point of releasing the incoherent snippet that RT gave the world?

If no more hard information is released, this one will have to go into the history books as "the unexplained TU 154 crash." Or perhaps as the TU 154 that crashed in the fog on a perfectly clear morning.

Kulverstukas

4th Jan 2017, 16:17

cockpit dialogue put out by RT news

It was not RT but Life.ru

Machinbird

4th Jan 2017, 16:59

To those considering selecting flaps instead of gear as the possible cause for this accident, consider instead this scenario:
1. Gear raised as per normal procedures.
2. In the process of selecting flaps from 28 to 15, the control was mis-handled or defective (depending on the original design concept) and was inadvertently selected to full up.) PF would not initially note much of a problem until the LE flaps began to retract and then all h*ll would break loose.
There isn't much handle travel between flaps 15 and UP. In the dark cockpit, it would be difficult to see the the mis-selection of flaps up until it began to cause problems.

If the flap handle design was intended to prevent direct selection to up from flaps 28, then wear or failure of some part of a mechanical interlock could be considered a system problem followed by the aircrew not realizing in time what they had (inadvertently) done wrong. This is essentially what is being reported, isn't it?
https://img-fotki.yandex.ru/get/41340/33837834.108/0_174b2d_d755b6b8_orig

This image was originally posted to this thread by Kulverstukas.
The origin of this image appears to be a Russian language blog by 'Denokan' on safety matters.
A google translate link to the blog is here:
https://translate.google.com/translate?hl=en&sl=auto&tl=en&u=denokan.livejournal.com%2F167530.html&sandbox=1
As an aid to interpretation read harvest=retract and chassis=landing gear
The thrust of this article is to move cockpit controls slowly and deliberately and to avoid rushing procedures.

DaveReidUK

4th Jan 2017, 17:45

If the flap handle design was intended to prevent direct selection to up from flaps 28, then wear or failure of some part of a mechanical interlock could be considered a system problem followed by the aircrew not realizing in time what they had (inadvertently) done wrong.

This is essentially what is being reported, isn't it?

Where have you seen it reported that inadvertent flap selection was the cause of the accident?

WBryanH

4th Jan 2017, 18:18

About the CVR text bits leaked to life.ru, “the flaps, b*tch!” ("Закрылки, с*ка!") and “Commander, we’re going down!” ("Командир, падаем!"), the flaps leak is wide open to interpretation. Did "one of the pilots" try to say what to do or not do with the flaps, e.g. 15-->28, 28 -->15, 15-->0? Or that he perceived a fail with them? Or maybe he said another word entirely? E.g. instead of "flaps" ("zakrylki") he said some similar-sounding word like "closed" ("zakrito")? Point is, this provocative life.ru leak gives min info and max plausible deniability.

This isn't like the Yak-42 crash in Yaroslavl, in which the private charter could take the blame for the loss of the beloved Lokomotiv team. This is the Russian AF, so maybe more potential direct govt accountability and embarrassment. With that in mind, we should question such a quick CVR leak, two days after the crash, via life.ru, an outlet well connected with Moscow authorities. This leak could be in part distraction, in part trolling for info/ideas. To tease Anons out of the woodwork who might know something.

That said, very many folks helped to recover crash remnants, and a few of you are posting some great high-res shots of some of it here. So making stuff up will have limits. But I'd be asking as much what we *don't* see as what we do see.

Chronus

4th Jan 2017, 18:56

The overhead panel photo in Machinbird`s post shows that there are no detents for intermediate flap selections. Accordingly selection appears to be reliant on visual confirmation of setting. So in terms of speculation, Machinbird`s would seem credible. Kulverstukas had earlier told us that the gear lights were located on the instrument panel. So in the visual, head down scan these will be easy to confirm. Is there anything similar for the flaps. Could someone with knowledge of the aircraft please offer some comment about the white band and the rider above it on the left side of the flap selector shown in the photo.

Kulverstukas

4th Jan 2017, 19:03

http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-14.html#post9627959

To the left of gear light you can see flaps indicator (round one with two dials) and further left HS position indicator. Slats control light is under gear lights.

guadaMB

4th Jan 2017, 19:42

Mr. Machinbird

You state as certain a flaps config for TO:

In the process of selecting flaps from 28 to 15, the control was mis-handled or defective (depending on the original design concept) and was inadvertently selected to full up.)

In Tu-154 -AFAIK- TO procedures are very variable, depending on several factors. It's a fully "analogic" design of the 60's.

Previously (post # 276) is shown a TO -from zero- with a 15º flaps config.

There are two certain data to the moment:

a.- flaps were at 0º at the moment of impact
b.- we ignore the preferred configuration selected by crew.

Karel_x

4th Jan 2017, 19:47

My attempt of translation radio comm with TWR:

TWR: 85572 write down: meteo at 2:00, RWY 24, wind... 5 m/s, RVR more than 10, QFE762/1016, friction 0.7
Tu-154: I wrote ....(repeating)
TWR: 85572 write down departure procedure: according flight plan, the path BINOL2A, FL 100, at 300 m work with Sochi APP 135.8, squawk 2444
Tu-154: ...(repeating)... Sochi APP 125.8...
TWR: 85572 Sochi APP 135.8
Tu-154: Sochi APP 135.8, 85572
TWR: 85572 tell me from where you plan T/O?
Tu-154: 85572 from the beginning of RWY, heavy
TWR: from the beginning...
Tu-154: ...
TWR: go on behind Follow-me car at RWY06 until crossing then at RWY02
Tu-154: ...RWY 02 ...
TWR: 85572, plane approaches RWY06, speed up taxi
Tu-154: 85572
TWR: 85572 behind Follow-me by TWY P, clear for ...., RWY24
Tu-154: (repeating)
TWR: 85572, report when ready for T/O
Tu-154: 85572 ready for T/O
TWR: T/O 85572, RWY24, wind 20 degrees 5m/s, clearence for T/O
Tu-154: 85572
TWR: 85572 Aproach 135.8

Maybe somebody Russian native can correct, add or improve :-)

DaveReidUK

4th Jan 2017, 19:54

The overhead panel photo in Machinbird`s post shows that there are no detents for intermediate flap selections.

Post #275 would suggest that there are, though they're hard to make out on the photo:

The flap lever can only be moved one stop by compressing the two side clamps, another stop requires a release of the hold and compressing the clamps again.

I can't imagine a complete lack of any detents making it past certification.

WBryanH

4th Jan 2017, 20:04

Karel thanks for this, I've been looking for it. Can you include the hh:mm:ss stamps?

Then I hope we can synch this, the ATC transcript, with the verified CVR transcript, if we ever see that latter transcript.

Kulverstukas

4th Jan 2017, 20:57

Its ATC (from post #15) not CVR transcript

AAKEE

4th Jan 2017, 20:59

Translation = from radio comms with TWR.

"Damn it" is supposed to be from CVR(If true).

WBryanH

4th Jan 2017, 21:04

Machinbird, in the cockpit pic in your post here: http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-15.html#post9629847 in between the two controls you circled in red, the black-handled flaps deploy control labelled закрылки (flaps) and gear control labelled шасси (gear), we see another control also labelled закрылки (flaps).

Anyone know what that middle flaps control does?

Mora34

4th Jan 2017, 21:14

Post #275 would suggest that there are, though they're hard to make out on the photo:

I can't imagine a complete lack of any detents making it past certification.
In this construction the "detent" is having to release and squeeze the side buttons of the lever when moving up/down a notch.

brian.crissie

5th Jan 2017, 18:15

“Commander, we’re going down!” ("Командир, падаем!")

OK, why was my very sensible question of whether "Commander, we're going down" might not be a mistranslation of "Commander, they're going down" (referring to the flaps) pulled?

I use 'падаем' casually for "let's go"

Chronus

5th Jan 2017, 18:34

In this construction the "detent" is having to release and squeeze the side buttons of the lever when moving up/down a notch.
Are the side mounted release buttons spring mounted, operating a mechanical gate lock/ lever link to an actuator. Are there any schematics or reference source on the flap/slat system.

Quadamp says :
"There are two certain data to the moment:

a.- flaps were at 0º at the moment of impact
b.- we ignore the preferred configuration selected by crew."

Karelx has quoted from ATC transcript :

"TWR: 85572 tell me from where you plan T/O?"
"Tu-154: 85572 from the beginning of RWY, heavy"

Taking the above on board, would it not be reasonable to assume some flap and slat would be expected for "heavy" t/o.

Kulverstukas

5th Jan 2017, 19:28

Translation is without any doubts "we are falling down". Period. Please stop speculate.

Kulverstukas

5th Jan 2017, 19:33

WBryanH, it's a switch under a cover with 3 position - On, Auto and Off. Don't make any guess from it - it's definitely not a/c in question and IDK which modification of 154 - M, or B, or B-2... You can check how different cockpit layout of this birds can be: Tu-154 cockpit/salon at russianplanes.net (http://russianplanes.net/f!b1!t1!a!c!d!l200!g2!m!s4!u!r!k!v!h!i!p1!reg!ser!n)

Ocean Person

6th Jan 2017, 04:06

Kulverstukas:

Thanks a lot for a most interesting gallery of interior pictures of the TU 154. I learnt more from them than any half a dozen written manuals. The flight deck appears rugged but functional and I found myself thinking I could have been quite at home in that environment. Your efforts are much appreciated.

gonebutnotforgotten

6th Jan 2017, 10:04

Does the Tu154 have a speed baulk or any other device to prevent retraction of the slats at too low speed?

Kulverstukas

6th Jan 2017, 10:40

AFAIK there is not. Except T/O configuration warning.

Kulverstukas

6th Jan 2017, 10:43

BTW good source of cockpit photos of 154M and B

1) Dokumentace obrazov?ho charakteru - Tupolev TU-154M detailní fotografie cockpitu (http://letadla.eleferno.cz/foto-index.php?galid=11)

2) russos | Tu-154B-2 CCCP-85327 (http://russos.dreamwidth.org/93341.html?thread=1173405)

3) Tu-154M electrical equipment manual (http://www.studfiles.ru/preview/2584158/page:11/)

kontrolor

6th Jan 2017, 12:29

Kulverstukas, is it possible that they selected flaps, but they didn't deploy and this went unnoticed? What would be the take-off run in this case?

EDLB

6th Jan 2017, 12:36

The IAS 'steam gauge' in the panel can hardly differentiate between 350 and 400km/h but the V2 and Vref speeds are given with 3 digits. So either the PF give it a good margin or there is another clue on IAS I overlook. If the scan of the PF uses this IAS instrument as reference for TO then I can hardly imagine that they give margin to the low side operating the flaps. A TO mostly over water is routine and not very demanding as long as all donkeys work. The tower RT transcript sounds relaxed and not busy at all.
Has anyone the max. speed limits for the 15 and 28 degree flap settings at hand?

Kulverstukas

6th Jan 2017, 12:49

they selected flaps, but they didn't deploy and this went unnoticed

Highly improbable.

What would be the take-off run in this case?

I'm not a pilot of Tu-5 but mostly everybody agree that in case of T/O without flaps they will end their flight in the fence instead of Black Sea.

Has anyone the max. speed limits for the 15 and 28 degree flap settings at hand?

http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-13.html#post9626860

Kulverstukas

6th Jan 2017, 12:57

Press conference (https://www.youtube.com/watch?v=QXjyt6o4VIw) of state committee of investigation (29/12/16):

Q: "You have just said that it is obvious that there was a technical malfunction, can you please clarify this point, I mean, now, according to the investigation, you realize that it was a technical failure in the plane..?
A: "Yes, but these issues will be clarified in the due process of technical investigations. As soon as reliable data, as well as the results of examinations, will be clear, they will be immediately presented to the public through the media..."

EDLB

6th Jan 2017, 14:27

Thanks for the info on the IAS gauges. That makes much mores sense. The pictures give the impression that only the right hand seat has the detailed IAS indicator and would therefore be the one calling/operating the flaps/slats.

@Kulverstukas thanks for your very helpful contribution. I was asking for the max. speeds allowed (Vfe) with flaps/slats in the 15 and 28 degree detention. That is the speed your instructor tells you that they will fall off if exceeded. In the table are the nominal speeds V2 and Vref.
Vfe is of interest to get an impression about the timing of normal procedures during TO.

Kulverstukas

6th Jan 2017, 14:41

the max. speeds allowed (Vfe) with flaps/slats in the 15 and 28 degree detention

15° - 420 kmh
28° - 360 kmh
45° - 300 kmh

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 wingThat 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

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

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

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

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:

gonebutnotforgotten

8th Jan 2017, 21:53

Mr K you are going to have to help us with that picture of the right wing - is there any portion of the movable leading edge (slat) visible? If so where is it and is it up or down?! Seems to me it's missing completely, which is interesting but not very informative. Thanks.

peekay4

8th Jan 2017, 22:16

I THINK the AC went down nose first.

Guada just because an aircraft may have crashed nose down, that doesn't mean it wasn't (still) stalled -- especially at low altitudes without enough time/space to recover.

(As example here was Colgan 3407 in accelerated stall with extreme nose down position, 2 seconds before impact, stick shaker & pusher activated, from NTSB analysis):

http://i.imgur.com/FlsxWVf.png

Machinbird

9th Jan 2017, 06:28

is there any portion of the movable leading edge (slat) visible?
Isn't there is a piece of the leading edge flap visible & retracted.
First look at Kulverstukas' pictures of the wing here: http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-17.html#post9633883 (http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-17.html#post9633883)
and look to the left of the large hole in the leading edge. The airfoil profile seems to be complete there.
Next, look at this TU-154 picture to see the leading edge flap configuration.
(Note: It is a realllly big image, so I am just linking it) http://www.airlinereporter.com/wp-content/uploads/2013/02/DSC_1345-15.jpg

gonebutnotforgotten

9th Jan 2017, 08:26

Machinbird

I've been studying all the pics of the 154 I can find and it's not obvious to me that the length of leading edge to left of the hole isn't just the fixed section behind the slat. It seems possible that the whole of the slat disappeared as one piece. If it did is it more likely that it was extended or retracted at impact? What does the left wing look like?

guadaMB

9th Jan 2017, 12:47

@peekay4 # 344

I meant a stall position after an excess of angle of attack.
Note: I don't think could happen in this unfortunate case, in which I guess the AC went straight to water with an angle just opposite.
But this is MY GUESS. Time to investigators (if made public what happened, thing rather difficult being a military Russian AC).

Chris Scott

9th Jan 2017, 13:50

Hola guadaMB,

Like lomapaseo I have never heard the expression "stall pose" in relation to an aircraft impact. I am thinking this may be used by personnel in your SAR work? Every profession has its own jargon. Did you mean "nose up"?

In case you do not know: in aeronautics there is a specific difference between "pitch attitude" and "angle of attack" (AoA, also known as "alpha"). When AoA is too high, the wing is stalled. As peekay4 and others have pointed out, an aircraft wing can be stalled even when the pitch attitude of the aircraft is nose-down. In that case, the rate of descent will be very great, but the aircraft will still have forward airspeed.

Hope this helps. :ok:

guadaMB

9th Jan 2017, 14:01

@Chris Scott #348

Did you mean "nose up"?

And I meant AoA in excess (this is not the case, as I think. The entire AC appears absolutely torn, washed off in pieces, besides it's a strong bird. Had to happen what you say: nose down, the rate of descent will be very great, but the aircraft will still have forward airspeed).

Chris Scott

9th Jan 2017, 14:05

Quote from Machinbird:
"Isn't there is a piece of the leading edge flap visible & retracted.
[...] look to the left of the large hole in the leading edge. The airfoil profile seems to be complete there."

I see what you are looking at, but I think we need a closer look to tell if it is merely the leading edge behind the slat, as gonebutnotforgotten suggests, or a small length of retracted slat.

Kulverstukas

9th Jan 2017, 14:09

Photos from Sochi (http://radikal.ru/users/0DarkAngel0#alb=85572)

Port wing?

http://s020.radikal.ru/i705/1701/0b/4af9382df226t.jpg (http://radikal.ru/fp/vrexd8hbft6vy)

Chris Scott

9th Jan 2017, 14:24

Thanks again Kulverstukas,

Is that trailing-edge flap fully retracted? :confused:

Kulverstukas

9th Jan 2017, 14:38

No, it's around 15° I think

EDLB

9th Jan 2017, 14:54

The leading edge slats seem to be in the deployed position on this side if that's not a result of impact damage. The trailing edge flaps is more difficult to say. On the far right end they look retracted, on the other side it is not as clear. The investigators will have more clues from the ballscrew positions. This wing has much less damage. The surf was higher as in the Hudson river and the impact was more violent, with no survivors left. The airplane was in any case too slow for a clean wing, so the investigators have to answer the question, how it came into the configuration indicated on the crashed remains.

guadaMB

9th Jan 2017, 14:56

In #164, @xeque asks laconically: Asymmetric flaps?
In #173, @Kulverstukas shows a wing with flpas fully retracted
In #351, @Kulverstukas shows the other wing with flaps "around 15º"

Could this asymmetry be the -not necessarily the only- cause of the tragedy?

aerobat77

9th Jan 2017, 15:00

the flap drive mechanism might be torn off by impact forces and the flaps lowered just by gravity on this photo, especially because on the first photo when the wing is lifted out of the sea in inverted position the flaps appear to be up.

i do not think we can learn much about the actual flap position at impact from these photos

guadaMB

9th Jan 2017, 15:24

It's almost impossible to move/loose flaps even if after a strong crash like this.
And if a section was left on the loose, the other ones would stay as when impacted.
Repairings are made with special wrenches attached at the motorized end of the screw mechanism.
And i think it's not the same wing...

aerobat77

9th Jan 2017, 15:53

good question , i would say the pictures on post 325 and 351 all show the same part of the starbord wing - in inverted position at the night photo when its lifted out of the sea. what do other here think ?

Chris Scott

9th Jan 2017, 16:11

Kulverstukas,

With the photo of the back view of a wing in your post #351, you refer to it as the "sideboard wing". Excuse me asking, but do you mean the "larboard" (port) wing, i.e., the left (L/H) wing? If I had to guess, I would say it was the starboard (R/H) wing, but I am not sure.

I agree with aerobat77 that the wing on the ship re-posted on #325 is probably also the R/H wing. But we agree that the quay-side photo first posted in #325 seems also to be the R/H wing.

What are your thoughts? Have we seen the L/H wing yet?

Kulverstukas

9th Jan 2017, 16:27

Post #351 - seems port i.e. left wing top up faced us with trailing edge. (flaps cowling bigger right to left).
Post #325 - seems starboard wing i.e. right, at the far top side visible place of gears cowling torn off

Kulverstukas

9th Jan 2017, 16:37

Or if we agree that this is preliminary placement of lifted parts, it's still the same right wing just seen from other angle...

http://s019.radikal.ru/i614/1701/e9/000f9336b714t.jpg (http://radikal.ru/fp/p0b8lrd8vhp4y)

guadaMB

9th Jan 2017, 17:27

The wing showed in post #325 (night scene) is NOT the one in the BIG PICTURE.
The latter seems to be longer and shows almost to the tip.
The #325 pic wing is a part closer to the hull.

comment: impressive the last pic. Shows the magnitude of the impact.

Kulverstukas

9th Jan 2017, 17:50

https://img-fotki.yandex.ru/get/49888/6154164.29e/0_bb4a3_5c9c86e_XL.jpg (https://fotki.yandex.ru/next/users/alex3saaba/album/126144/view/767139)

https://img-fotki.yandex.ru/get/43572/6154164.29f/0_bb4a4_e8690e19_XL.jpg (https://fotki.yandex.ru/next/users/alex3saaba/album/126144/view/767140)

Also RA is visible on night shoot.

aerobat77

9th Jan 2017, 17:55

it is very important to clarify if its the same wing on 325 and 351 or not.

the picture on 325 shows clearly flaps up , in 351 partially down . if its the same wing it may mean nothing beyond a torn off drive mechanism and gravity deployment by placing the wing inverted or not .

if 325 ist the starbord wing ( flaps up ) and 351 is the port wing ( flaps partially down ) we have a strong indication of flap asymmetry !

Chris Scott

9th Jan 2017, 18:13

On a completely different tack, are we to understand that, unsurprisingly, the TU-154 has a natural tendency to dutch-roll at low altitude, as apparently demonstrated in this video?

https://www.youtube.com/watch?v=XzyUIhAyfzs&feature=youtu.be

If so, I presume the rudder has one or more yaw dampers?

henra

9th Jan 2017, 18:25

Post #351 - seems port i.e. left wing top up faced us with trailing edge. (flaps cowling bigger right to left).

Looking at the other pictures of that series I would strongly tend say: Starboard wing.
???????-????: ????????? ????????????: 0DarkAngel0 (http://radikal.ru/users/0DarkAngel0#alb=&img=6145112226)
It is Right side up, and the flaps are longer on the left side of the part, i.e. left side is towards the fuselage.

Post #325 - seems starboard wing i.e. right, at the far top side visible place of gears cowling torn off[/QUOTE]
Agreed.

Chronus

9th Jan 2017, 18:37

Kulverstukas

9th Jan 2017, 18:39

Yes, if it was a question

Prada

10th Jan 2017, 00:28

it looks like right wing outer flap actuators are disconnected. There are two of them and the are located at the both ends of the flap. Thus, position of the flap on the picture does not refelect their position right before accident.

Kulverstukas

10th Jan 2017, 18:18

Flaps

https://cdn.aviaforum.ru/images/2017/01/820771_4e5fe9eac765c41f6b95ab29ac882495.jpg

Kulverstukas

10th Jan 2017, 18:19

Main gear lock(s)?

https://cdn.aviaforum.ru/images/2017/01/820788_e9c63b46a747c9b345c7b9f26b76510e.png

https://cdn.aviaforum.ru/images/2017/01/820789_7692ba915872da3c853d455dab171bd9.png

https://cdn.aviaforum.ru/images/2017/01/820821_4d6fb4e86a664850147c1ce677ddbdbe.jpg

Chronus

10th Jan 2017, 19:04

Yes it was, thank you Kulverstukas. That being the case it would expect that for ease of access, it would be retained by means of the usual quick release fasteners. It does not appear to be greatly deformed and not folded back, almost neatly peeled off. Cannot see the other side of it but it appears from what can be seen to have in the main, retained its form. In considering the possible impact trajectory it may provide some clues. Such as a break of the tail section with a high AoA on impact.
The hydraulic hoses shown on the gear pictures are curious. Are they sleeved, they seem to be lacerated, what are those marks around the circumference of the top hose. Are they some sort of binding or are they tear marks. Difficult to tell from the photo.

Kulverstukas

16th Jan 2017, 10:32

http://images.vfl.ru/ii/1484549906/5fbb29ed/15693689_m.jpg

HarryMann

16th Jan 2017, 13:45

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."

Yup... agree entirely DaveReid.. incl. crawling inside :)

Chris Scott

16th Jan 2017, 18:17

Good evening Kulverstukas,

In the latest picture you have posted (in #372), is that the R/H (starboard) wing again?

If so, is the L/H (port) wing missing, or in small pieces?

Kulverstukas

16th Jan 2017, 18:25

If so, is the L/H (port) wing missing, or in small pieces?

I think so.

Chronus

17th Jan 2017, 18:19

Kulverstukas photo no 373 shows the pax terminal in the background. Is all this debris and wreckage strewn all over the apron in view of the travelling public.

Kulverstukas

17th Jan 2017, 18:25

It's cruise ship terminal and it's closed for winter.

buttrick

24th Jan 2017, 03:16

We can't really say this or anything else with the facts we have now. Therefore it would be helpful to know what this ATC tape really says after the take off.

Fuel stop is what the consensus seems to be. Planned stop.
Probably so they wouldn't have to upload fuel in Syria

megan

24th Jan 2017, 04:37

the TU-154 has a natural tendency to dutch-roll at low altitude, as apparently demonstrated in this videoChris, was apparently caused by miss wiring of some element of the flight control system.

Barely controllable Tu-154 - another UA232 [Archive] - PPRuNe Forums (http://www.pprune.org/archive/index.php/t-450293.html)

Chris Scott

24th Jan 2017, 11:20

Hi megan,

You've misquoted my question as an assertion! := For the benefit of any newcomers, this was my question:
"...are we to understand that, unsurprisingly, the TU-154 has a natural tendency to dutch-roll at low altitude, as apparently demonstrated in this video?"

Admittedly my assumption was and is that it does have the tendency, which necessitates a yaw-damping system, and that it was a major malfunction of the system that caused the videoed incident. That malfunction apparently involved cross-wiring, which may have exaggerated the tendency. Thanks for the link.

I'm wondering, however, if a simple absence of yaw damping, due to a spontaneous failure of the system, might itself render the aircraft difficult to control after take-off. Presumably, in this case at Sochi, the system was working normally on the previous sector. But even that is conjecture.

megan

25th Jan 2017, 08:18

Kulverstukas, are you aware of any formal finding on the TU-154 dutch roll incident mentioned by Chris Scott?

XzyUIhAyfzs

Kulverstukas

25th Jan 2017, 17:02

It's military, so no public acess to investigation papers.
Except this short notice: https://ria.ru/inquest/20110513/374115628.html
And this pathetic article (summarized rumors, leaks and some forum discussions): Tu-154 (http://www.kompravda.eu/daily/25689/893510/)

Translate with Google.

In short, there was some wrong wires connection at EFCS which cause inversion of pitch and roll compensation signals.

PS: A bit reminds this one: https://en.wikipedia.org/wiki/China_Northwest_Airlines_Flight_2303 and this: https://ru.wikipedia.org/wiki/%D0%9A%D0%B0%D1%82%D0%B0%D1%81%D1%82%D1%80%D0%BE%D1%84%D0%B0 _%D0%A2%D1%83-134_%D0%B2_%D0%94%D0%BE%D0%BD%D0%B5%D1%86%D0%BA%D0%B5

Chris Scott

25th Jan 2017, 18:32

Thanks for those links, Kulverstukas. (The Google translations are hilarious...)

Regarding the videoed dutch-roll incident, you mention crossed-wiring in the EFCS. We can presumably rule-out that being done at Sochi.

Re EFCS, I think this aircraft design predates fly-by-wire flight control systems, so we are simply talking about a dedicated yaw-damper system. Most if not all western swept-wing airliners have had yaw dampers - certainly since the 1960s. No doubt some need them more than others. The anhedral of the Tu-154 is said to reduce the tendency to dutch-roll, but it would be interesting to know how the aircraft behaves in the absence of yaw damping.

Karel_x

26th Jan 2017, 19:54

In short, there was some wrong wires connection at EFCS which cause inversion of pitch and roll compensation signals.

There are pictures of wrong terminal connection available on the internet.

Correct connection:
http://cdn.fishki.net/upload/post/201502/15/1429291/5_10.jpg

Actual connection at RA-85563:
http://cdn.fishki.net/upload/post/201502/15/1429291/4_11.jpg

Herod

26th Jan 2017, 20:41

There are pictures of wrong terminal connection available on the internet.

Now THAT is an accident waiting to happen. Murphy's Law and then some.

GotTheTshirt

27th Jan 2017, 09:25

Herod I don't know if your age is correct but when I was a lad all electrical connections were like this !!:)

Kulverstukas

27th Jan 2017, 10:07

I think he means color codes. I saw same way of engineering at color coding power connections for submersible Grundfos pumps, leading to same (albeit less deadly) results.
Back to Tu-154, if I recall correctly, it's power wiring of damping motors and they must work in antiphase to input signals, so they used cheap solution. IIRC there was a Tupolev's bulletin to remark them after this "dance".

Herod

27th Jan 2017, 10:37

Thanks, Kulverstukas. Yes, the colours "connect the green terminal to the red terminal, and the red terminal to the green one." Somebody a bit tired, or rushed, and we can see the result.

Chris Scott

27th Jan 2017, 16:09

I still don't understand this fully. Did the transposition of the wiring also stop the crew from simply turning the yaw damper off?

Is there an ON/OFF switch? Failing that, is there a CB?

Kulverstukas

27th Jan 2017, 21:48

There you absolutely right, but is's a case of be wise after the event. There is the switch.

Kulverstukas

28th Jan 2017, 13:38

http://images.vfl.ru/ii/1484550020/4010521e/15693700.jpg

Chris Scott

28th Jan 2017, 14:21

Thanks K,

So that's the starboard-side and fuselage wreckage laid out within a rough outline of the aircraft. It would be interesting to see what they've got on the port side.

Karel_x

29th Jan 2017, 10:19

Concerning dancing plane - the plane was stored for almost ten years. My experiences allow me to imagine a scenario that from time to time somebody went to "borrow" spare parts from the plane. They could return it to the cannibalised machine after original part came. It is very dangerous moment, non standard operation, without checks.

The colour code surely has its logic for electric engineers.

Machinbird

30th Jan 2017, 13:45

The colour code surely has its logic for electric engineers. If that is supposed to be phase wiring for 3 phase power, then the correct sequence is not at all logical..

Speaking from experience, cannibalization of an aircraft greatly increases the risk of maintenance error, even when a serious attempt is made to control the resulting maintenance.
Once an aircraft is perceived to be a wheeled parts bin, it is easy to create an attitude that permits uncontrolled removals of equipment thus creating colorful experiences for the crews flying the aircraft when an attempt is made to return it to service.

Chris Scott

30th Jan 2017, 14:23

Hi Machinbird,

Unfortunately, we still have no information on the dutch-rolling characteristics of the Tu-154 with the yaw damper system simply turned off. I was hoping a Tu-154 pilot might comment.

Machinbird

31st Jan 2017, 02:16

There is a month old report that appears to hint at a specific failure that we have not been discussing:
Preliminary Findings Point to Flap Problem in Tu-154 Crash | Defense News: Aviation International News (http://www.ainonline.com/aviation-news/defense/2016-12-28/preliminary-findings-point-flap-problem-tu-154-crash)
There is a background statement that may be relevant:
An SPZ-1A sensor device is used to monitor whether the flaps move symmetrically; if they do not, it de-activates the hydraulic actuator and issues a warning to the crew to assume manual control. The Tu-154B-2 flight manual and other documents prescribe using an electrically-controlled stabilizer and control yoke to offset the diving force that the flaps generate should they have not retracted. Crews are required to perform simulator training to deal with such a situation. If the failure of the flaps retraction mechanism is discovered in a timely manner, the pilots are instructed to land at the nearest airfield while maintaining a relatively low speed. They are also instructed to keep the throttles at a low setting so that the engine thrust does not further complicate the issue of aircraft stability and controllability.So what would be the result of overspeeding extended but deactivated trailing edge flaps? Could that be a reason the aircraft did not climb significantly?

Chris Scott

31st Jan 2017, 10:02

Hi Machinbird,

To be fair, I think other posters have previously speculated on both slat/flap asymmetry and premature retraction of slats and/or flaps.

I'd be interested to hear your opinion, but it seems to me that the paragraph you quote was written by someone with limited knowledge - probably a journalist doing his/her best. It's partly incoherent.

However, I'm guessing that, in the event the crew detects asymmetry during retraction, there may be a way of freezing the surfaces in their present position. That could explain the extra switches on the overhead panel shown in this photo posted by Kulverstukas:

http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-7.html#post9621956

I refer to the switches just to the left of the L/G lever. Perhaps Kulverstukas will comment.

To take an admittedly distant example, and IIRC, the B707 has override switches for the inner and outer T/E flaps that freeze the flaps hydraulically, but enable them to be moved electrically.

Obviously IAS has to be limited if slats and/or flaps remain partially extended. That in itself should not compromise initial climb performance, but the stated necessity to limit thrust certainly would.

Heathrow Harry

31st Jan 2017, 10:38

I'd just like to say thanks to kulverstukas

Without his/her pictures and measured commentary this thread would be the usual wandering conspiracy theory post-fest

Kulverstukas

31st Jan 2017, 12:25

Chris, switch left of gears lever (partly crossed by red circle) is auto/manual/off switch for flaps. Far left cluster is landing lights.

@Machinbird, figures from this article (like 500 kmh) were dismissed later by officials. Also last joint report from IAC-Defence commission states that there was no malfunctions found at flight data.

Karel_x

2nd Feb 2017, 18:26

Hi Machinbird,
...However, I'm guessing that, in the event the crew detects asymmetry during retraction, there may be a way of freezing the surfaces in their present position. That could explain the extra switches on the overhead panel shown in this photo posted by Kulverstukas...

Yes, it is correct. The flaps retracting is interrupted automatically if the asymmetry exceeds safety limit. I think 15%. After it, the crew can switch it manually for starting automatic resymmetrising procedure.

Kulverstukas

7th Feb 2017, 13:17

CVR and FDR readouts doesn't help much with investigation of the accident. Defence ministry doesn't agreed yet with version about crew error (particularly flaps instead of gears retraction) as the case of crash. MAK and Central Aerohydrodynamic Institute (TSAGI) will make mathematical model of the flight, which will help calculate two still unknown figures - TOW and centering, source told "Kommersant" newspaper.

https://ria.ru/incidents/20170207/1487313165.html

Karel_x

10th Feb 2017, 21:17

CAGI was not reportedly asked to do any expert works concerning the disaster. Near the CAGI, south of Moscow at Zhukovky, also Gromov Flight Research Institute (LII) is located. Analysis of FDR and CVR did not help to find the reason of disaster, no system failure was found.
At this moment, LII specialists work on computer model of fatal flight. They use mathematics model of Tu-154B and recorded flight parameters from FDR (hight, IAS, angles, controls...) and they are trying to find the set of factors (TOW, CG, flaps falure etc.) that is fully compatible with actual data from FDR. For this reason they may be trying to do some special test in wind tunnel of CAGI (partly retracted gears, flaps..?).

In parallel, mechanical analysis of debris are provided to find any track of in-flight failure.

Chris Scott

10th Feb 2017, 23:41

Thanks Karel_x,

I may be missing something, but so far I still did not recognise any debris from the left wing in any picture I have seen.

Kulverstukas

11th Feb 2017, 09:52

I think it's shredded in such small parts that is not interesting for journalists to photograph.

Also JFYI reports are constantly published since daily or weekly that rescue operation continues and N a/c pars and M body fragments rescued from the sea floor.

Karel_x

11th Feb 2017, 19:04

Few days ago there were non-confirmed information in media. Based on FDR record, events reportedly developed as follows:

- in 3rd minute of the flight, Tu5 was at 450mASL
- first warning event was a signal from sensors of directional stabilising system (some kind of plane asymmetry?)
- Tu5 begun a sharp descent (supposed flaps problem)
- AoA exceeds limits
- The crew tried tu do a turn for a return to the airport
- First high speed contact with water had a tail part, immediately followed the right wing

It is not clear how certain this rumour is.

AN2 Driver

11th Feb 2017, 20:35

signal from sensors of directional stabilising system

Would that be another description for the Yaw Damper?

Kulverstukas

12th Feb 2017, 11:37

Few days ago there were non-confirmed information in media.

It is not clear how certain this rumour is.

I'd like to check where it came from as it's doesn't adds up to any info we have now from other sources... :(

Karel_x

12th Feb 2017, 13:50

Would that be another description for the Yaw Damper?
Yes, I suppose that the sensor is one of three axis gyroscopes. I used the original wording.

I'd like to check where it came from as it's doesn't adds up to any info we have now from other sources...

The original source maybe Life.ru:
https://life.ru/t/%D0%BD%D0%BE%D0%B2%D0%BE%D1%81%D1%82%D0%B8/953166/pieried_krushieniiem_tu-154_srabotal_datchik_prievyshieniia_ughla_ataki

You can find it at many sites (all in Russian):
??????????? ??????? ??????? ?????????????? ??-154 ? Pzik (http://pzik.ru/?p=18508)
Ìèíîáîðîíû: Òó-154 óïàë èç-çà îøèáêè âòîðîãî ïèëîòà » Svopi.ru - Íåçàâèñèìûé èíôîðìàöèîííûé ïîðòàë Ðîññèè è Áåëîðóññèè (http://svopi.ru/proish/149184)

Kulverstukas

12th Feb 2017, 16:07

Sorry, Karel, all this is crap is outdated and based at speculations which were not backed by any "official" or reliable evidence (such as debris photos, press releases and briefings of Def Ministry or MAk, or even "first hands leaks", not reprints through long chain of sites).

PS: Life mentioned AoA warning (which is consistent with their "leak of CVR recordings") and other two are just perfect example of brainless journalie (http://images-cdn.9gag.com/photo/a3YBZE3_700b_v3.jpg) where they tried paraphrase it in their own words and failed.

Karel_x

13th Feb 2017, 06:40

:) OK Kulverstukas, it may be fully journalistic speculation or fantasy.

Nevertheless I think that they must hear somewhere the sentence about "directional stability sensor signal". I don't suppose that they can fabricate it by themselves. It is too concrete and too specialised. But it is not clear what exactly it means. So, IF it is true, the plane had to do some kind of rotation movement around vertical axis. Maybe because of some aerodynamic asymmetry. Flap asymmetry, gears retraction asymmetry, some cover? We can find possible relation with the information that some additional aerodynamic research may be done in the wind tunnel of CAGI.

Leaked CVR record was never confirmed, but they started investigation about the origin of leakage. So I believe that it is more or less actual. There are the two acoustic warning signals recorded. One of them can be AoA warning. I am not sure that Tu5 is equipped with TAWS. Have you any idea what the second signal is?

Kulverstukas

13th Feb 2017, 10:17

OMG, Karel, both links you posted as example are just mindless reprint of some equally doubtful source with even wrong spelling of Lubertsy (Lubentsy ? :E) where Airforces Institute is located and picture too stupid to even laugh about. If you make Yandex search of "Directional stability sensor signal" (in russian, exactly as they put it in the articles) all results are just from traffic-baiting cites and third grade "news consolidator" web sites.

Karel_x

13th Feb 2017, 19:32

Kulverstukas, I am surely not an advocate of life.ru.

I commented it: "Non-confirmed information in media....not clear how certain this rumour is."

You wanted to investigate a credibility of it, so I gave you the links and wrote that the origin source is probably life.ru. I explained what piece of information looks interesting for me. Yes, it is poor speculation, so I introduce it: "IF it is true..." That's all.

You evaluate it as nonsense. Probably you are right :).

PS
I am sorry, I found now that link to the original source was not correct. It should be:
https://life.ru/t/%D1%8D%D0%BA%D1%81%D0%BA%D0%BB%D1%8E%D0%B7%D0%B8%D0%B2%D1%8B/967874/nie_khvataiet_dannykh_prichiny_padieniia_tu-154_vyiasniaiut_s_pomoshchiu_truby

Kulverstukas

14th Feb 2017, 06:22

Karel sorry if my answers looks a bit rude, but we are just fed up here with nonsense published in any media by brainless attention seekers.

Your last link it seems is full of hints and leaked info, if you strip it from usual misinterpretations and imagination. Not that there is something new in it, everything was published before but in this article they managed to consolidate what was said up to date. However, I'd totally dismiss last part with "Directional stability sensor signal" because until now it's not backed up with any other confirmation from independent "leaked source".

Karel_x

22nd Feb 2017, 19:07

After computer modelling, investigators plan to provide several real flights with identical plane with test pilots in cockpit and engineers aboard. First of them will be provided in daylight for good orientation. They will try to repeat most of conditions of fatal flight and record data from sensors. It should be done at Zhukovsky Intl Airport, from the longest RWY 12/30 (5402mх120m).

At the crush site, divers are continuing their work.

Karel_x

27th Feb 2017, 15:50

Air photo of the fragments collecting site:

http://bloknot-krasnodar.ru/upload/iblock/4a7/n3vplwmsocg-2.jpg

The left wing is much more fragmented, it looks that she has a left roll in the moment of high speed (510 km/h) water impact.

(In the original article its author speculate about explosion)

HighAndFlighty

27th Feb 2017, 18:33

Is it just me or is the right horizontal stabilizer pretty much missing?

Kulverstukas

8th Mar 2017, 19:15

https://cdn.aviaforum.ru/images/2017/03/831337_77347ec8033b6ab28eca32900f6606ff.jpg

Kulverstukas

14th Mar 2017, 05:06

archae86

14th Mar 2017, 13:58

This story (https://themoscowtimes.com/news/russian-military-pilot-in-fatal-black-sea-crash-was-in-full-control-of-plane-reports-57412) posted (in English) at the Moscow Times appears to stem from the same source as that posted by Kulverstukas, though it is much shortened.

Karel_x

15th Mar 2017, 21:46

Today Kommersant (http://www.kommersant.ru/doc/3241365) newspaper printed sensational article that until last second flight was under pilot control an that accident was CFIT possibly because Cpt lost orientation.

UPD: Somathogravic illusion...
Lady speaker of Investigation committee, Svyetlana Petrenko, declared that the hypothesis ... are not based on facts and are only personal meanings of its authors.

Kulverstukas

26th Apr 2017, 18:29

Latest update posted today (https://www.gazeta.ru/army/2017/04/26/10645469.shtml#page1) as another "leak from the source inside investigation body". Plane was overloaded - instead of 98 t it takes off in Adler with TOW=110 t. Plane was overloaded at Chkalovsky, but it was fueled in Sochi/Adler and presumably crew was not aware about real weight of the cargo, so they ordered top filling.

Chronus

26th Apr 2017, 19:46

+12T ? That would a bit over the top. But if the load was the same at previous then how come they did not to hit the deck earlier.

Kulverstukas

26th Apr 2017, 19:50

Article claims they flew from Chkalovsky having TOW=99,6 with 24 t of fuel. At Sochi they topped it to 35,6 t.

Prober

27th Apr 2017, 08:02

Five months to produce credible loadsheets? Surely not!:E

andrasz

27th Apr 2017, 09:08

@Prober,
IF the claim has any relation to the truth, one would presume that the LS prepared & presented to the crew did not reflect the correct payload.

While the TU5 is a forgiving bird with a lot of overengineering and probably you could achieve a successful planned takeoff at 10 tons over MTOW, same cannot be said if speeds and flaps settings are based on a lower weight. The table presented by Kulverstukas (http://www.pprune.org/rumours-news/588730-tu154-out-sochi-missing-13.html#post9626860) shows a 15-20 Kph difference in reference speeds for every 10 tons of weight increase.

Herod

27th Apr 2017, 10:05

If they were false loadsheets done without the crew's knowledge, someone deserves a very long prison sentence. What a stupid, and tragic, waste of lives.

andrasz

27th Apr 2017, 10:25

@Herod
With some insights into soviet and post-soviet aviation, I would not assume wilful falsification, simply a math error or ommission that went unnoticed by the crew. Probably the LS was done manually, while the layout and workflow is well designed (I used to instruct how to prepare those many moons ago) errors can still be made.

Still, the quoted numbers would imply a payload of 24 tons, (OEW is ~51 tons), that sounds unrealistically high given the known number of pax (83), so I would hold my breath on this one for the time being (unless of course there were also some undeclared long heavy olive-green wooden boxes on board, but if that was the case we will not hear about it...).

EDLB

27th Apr 2017, 12:40

Andraz has sure more insight. However it does not make sense to keep the overload, if for some olive stuff reason or whatever, from the pilots. On that sea level takeoff they would have gotten away with adjusted speeds. At least that they made it over the fence proves this. Why endanger the people and plane?

Chris Scott

27th Apr 2017, 13:53

Quote from andrasz:
"...and probably you could achieve a successful planned takeoff at 10 tons over MTOW, same cannot be said if speeds and flaps settings are based on a lower weight."

Agreed. And also the speed schedules for flaps and slat retraction, and minimum clean speed...

gonebutnotforgotten

27th Apr 2017, 16:05

Assuming an overload of 12t, Kulverstukas's table (post 246) would suggest Vref(0) should be 24 km/hr higher, call it even 30 km/hr or 15 kt. But presumably (?) Vref = about 1.3 Vstall, so the stall margin would be nearer 100km/hr, and a 30 km/hr error shouldn't spell disaster. What am I missing? None of these recent revelations seem to fit the leaked voice recorder exclamations, do they?

Kulverstukas

27th Apr 2017, 19:06

Latest "leak" was dismissed by Investigation Committee. Exactly like previous time when "leaked" story was about somatogravic illusion.

andrasz

28th Apr 2017, 05:40

Expected so, 24 tons for 83 pax would translate into nearly 300kg per pax, you'd need all the empty seats filled with bags to achieve this.

Kulverstukas

28th Apr 2017, 09:10

Something small but heavy in cargo compartment? More so, it's almost unbelievable that crew doesn't get a feeling of the load at the first takeoff and then ordered refilling to the top at the second.

HHornet

29th Apr 2017, 07:26

Kulverstukas said "Something small but heavy in cargo compartment?". What about shifting cargo ?

Kulverstukas

29th Apr 2017, 08:09

It's not 748 with cargo compartment going from nose to tail. So cargo can't shift more than couple meters.

guadaMB

30th Apr 2017, 09:53

Something small but heavy in cargo compartment? More so, it's almost unbelievable that crew doesn't get a feeling of the load at the first takeoff and then ordered refilling to the top at the second.

Is it confirmed no extra cargo added in Sochi?

Kulverstukas

30th Apr 2017, 17:55

Nothing was loaded, nobody boarded and no one leaves the plane.

atakacs

3rd May 2017, 20:52

You mean that as a fact ?

No fuel ?

Hotel Tango

3rd May 2017, 21:20

Fuel was taken on but there was no additional extra weight in terms of passengers and cargo.

atakacs

3rd May 2017, 22:15

Understood.

Presumably the aircraft initially departed with full tanks?

grizzled

4th May 2017, 00:21

Understood.

Presumably the aircraft initially departed with full tanks?

atakacs: We aren't sure at this point but see kulverstukas post #423.

Kulverstukas

4th May 2017, 16:33

Understood.

Presumably the aircraft initially departed with full tanks?

Planned route was Chkalovsky - Mozdok - Syria. En-route they was diverted to Sochi. So presumably crew recalculated fuel and ordered refueling. Also there was some indication that crew was aware - in the leaked audio recording from radioscanner at the plane-tower communication Cptn added "heavy" to callsign. They also decided to takeoff from the treshold which is quite unusual for this rwy.

gonebutnotforgotten

4th May 2017, 17:16

TU 154 Heavy??

How odd that the crew should add 'Heavy' in their ATC comms. The lower band of the ICAO Heavy category is 136t so what did they mean as the 154's MTOW is around 100t isn't it?

andrasz

4th May 2017, 18:24

Yes, certified MTOW of the B-2 is 98t (the newer M had it increased to 102)

Karel_x

5th May 2017, 18:55

The communication was little different. All was on Russian, it was an answer for ATC lady question - something like this: (We want to departure) from beginning (of RWY because we are) heavy.

Chronus

5th May 2017, 19:21

I wonder whether a grand piano or two were loaded, along with the Alexandrov Ensemble.

gearlever

6th May 2017, 15:55

Not nitpicking, just to be correct on the terminology. You can have a PTOW well below MTOW and vice versa.

BluSdUp

6th May 2017, 16:16

Ehh,, a what?
Please elaborate. And whatever it is I like to learn.
The Dutch, by the way, has a good word for Nitpicking: Miren-Nauken.
Hard to interpret without censor.

gearlever

6th May 2017, 16:19

PTOW (performance limited TOW) may be well below MTOW (structural limit).

EDLB

6th May 2017, 17:09

Folks, we talk here about a see level take off with no indication so far on any engine failure at 8 centigrade OAT. So you try to make the point that with a few percent above MTOW that plane will fall out of the sky?
That's almost Alaskan conditions where even the FAA does allow for a 10 percent overload over "normal" lower 48 MTOW.

Every 60 degrees steep turn is a 2x MTOW maneuver. Never done in your life?
So don't set the rumor mill for any non flying jurno on high gear.

Karel_x

6th May 2017, 19:55

We should keep on mind that Svyetlana Petrenko, the speaker of investigating committee, declares previous month that the overweight theory doesn't correspondent to established actual conditions.

gonebutnotforgotten

6th May 2017, 22:35

The communication was little different. All was on Russian, it was an answer for ATC lady question - something like this: (We want to departure) from beginning (of RWY because we are) heavy.
Thanks, that makes a lot more sense.

andrasz

8th May 2017, 14:45

To lay all these overweight rumors to rest, I checked my old notes (all figures metric tons, for TU5 B-2 model):

OEW ~51.5 tons (depending on cabin configuretion, number of crew, etc.)
MAX FUEL 37.6 tons (meaning all tanks full)
MTOW 98 tons

This means that with full fuel tanks the permissible maximum payload is ~10 tons, that is exactly what you would expect for 98 passengers and their baggage (an orchestra's instruments in their protective cases are bulky but not particularly heavy, the luggage would fill the holds to maximum volume leaving room for little else). The ATC communications confirms that the crew knew they were at/near MTOW.

Kulverstukas

8th May 2017, 17:04

98 passengers and their baggage (an orchestra's instruments in their protective cases are bulky but not particularly heavy

Don't forget that except the ensemble there was couple TV crews with their equipment and Dr.Lisa (Russian F. Nightingale) with unknown amount of humanitarian aid.

OEW ~51.5 tons (depending on cabin configuretion

This particular a/c has it's first passenger compartment converted into saloon which reduced it's seat capacity.

Harry Wayfarers

10th May 2017, 18:13

Tail heavy?

andrasz

11th May 2017, 05:43

...unknown amount of humanitarian aid

Ah, I did forget about that...

Tail heavy?

Very difficult to achieve with the kown loads. I remember that even if you had the rear cabin full (~100 pax) and loaded all the bags that could fit in the rear hold, the bags that remained (~50%) loaded in the front brought the CG to within limits. It only started becoming tricky with a full payload and a light fuel load, where CG was getting close to the front limit, and with the graph being V shaped it moved even closer as fuel was used up.

Kulverstukas

24th May 2017, 12:12

Defense Minister Sergey Shoigu blamed those who "spread unverified information and speculations" and said that investigation results will be published "soon".

Kulverstukas

30th May 2017, 21:44

Latest update.

Totally and fully human factor.

4 pages in russian of final report are available. Must I publish them?

atakacs

30th May 2017, 22:12

Can you summarize it?

Kulverstukas

30th May 2017, 22:20

It's bit longish and there is deep night here. In short - cpt lost orientation and CFIT plane into the sea :(

damirc

30th May 2017, 22:50

Loss of situational awareness by the captain.

- They took off at 05:25:10 with 4 deg pitch up and with 300 kph speed.

- After gear up the pitch increased up to 15 deg pitch up at which point the captain started pushing the yoke away from himself.

- at 05:25:29 at an altitude of 157 meters flaps up was selected (although during the briefing this was to be at an altitude of 500 meters). During this the captain was still pushing the yoke away from himself (ie: less pitch)

- Due to the actions of the captain, at an altitude of 231 meters, and at a speed of 360 kph the aircraft started descending.

- At 05:25:39 they were at an altitude of 218 meters, speed 373 kph, pitch down 1,5 deg and vertical speed -6-8 m/s when the SSOS (horn and indiciation light warning "Danger, ground")

- During this the captain "energetically" (sic) turned the yoke from 10.7 deg right to 53.5 deg left within 1 second, after which he pressed the left foot control by 1/2, while also pulling the control yoke towards himself

- The aircraft continued descending due to the excessive roll

- at 05:25:46 they were at 90 meters altitude, speed 464 kph, left roll 27 deg, vertical speed -20m/s, and 2 deg pitch down

- at an altitude of 67 meters with a left roll of 35 deg the light indication "Left roll angle excessive" was lit, and after 1.2 seconds at an altitude of 34 meters with a speed of 514 kph the yoke was turned to the right to it's maximum and pushed away to it's neutral position

- at 05:25:49 after 73 seconds since the take off roll started, at 1270 meters from the coastline the aircraft crashed with a speed of 540 kph, left roll approx. 50 deg, course 220 deg, -4 deg pitch down, vertial speed -30m/s

Apologies for the imperfect translation.

atakacs

31st May 2017, 05:00

These seem like very "heavy handed" control inputs. Is the report definitive about no external factor (from loss of some control surface to cargo shift).
Any mention of the CVR ? What was the other pilot doing ?

I am really having an issue with "During this the captain "energetically" (sic) turned the yoke from 10.7 deg right to 53.5 deg left within 1 second" - why would he do that ??

Kulverstukas

31st May 2017, 05:40

Any mention of the CVR ? What was the other pilot doing ?

During taxi Cpt was in trouble locating his position and takeoff course...
...
Dangerous situation starts to unfold at 05:24:42,8 after 7s of takeoff run at 70kmh when Cpt begin emotionally asking the crew about current t/o course. Using f-words and emotional pressure instead of normative SOP distracted Cptn and crew from the procedure.
...
- Due to the actions of the captain, at an altitude of 231 meters, and at a speed of 360 kph the aircraft started descending with vertical overload became less than 1g. Nav commented on exhale "holy ****"
...
- At 05:25:39 they were at an altitude of 218 meters, speed 373 kph, pitch down 1,5 deg and vertical speed -6-8 m/s when the SSOS (horn and indiciation light warning "Danger, ground") sounded, Nav calmly finished "...[flaps] came up, synchronized, ****, what the f**k!?"
...
Crew informed Cptn about warnings and descending of the plane.
...

Link to the scan of the report: https://aviaforum.ru/threads/katastrofa-tu-154-ra-85572-bliz-sochi-oficialnaja-informacija.43924/page-21#post-2051670

atakacs

31st May 2017, 05:43

So no comment nor control input from co-pilot?

Kulverstukas

31st May 2017, 05:54

This pages are not investigation report, but rather memo with the list of reasons and contributing factors (from second half of the second page on) of the accident, sent out to the air forces regiments. So unfortunately no such details.

EDLB

31st May 2017, 10:49

Holy cow. So they let a captain fly which could not even manage an obstacle free sea level take off at 8 centigrade OAT in a perfect serviceable plane?

atakacs

31st May 2017, 12:08

Avro_Arrow

31st May 2017, 12:09

PIC incapacitation followed by a CRM failure?

Kulverstukas

31st May 2017, 13:35

I guess this being operated as a military flight there will not be a formal report?

It's too important to make no open report now. Also IIRC IAC was involved.

Machinbird

1st Jun 2017, 03:33

To sum up the Captains performance:
He seems not to have been in control of himself.
This type behavior is what you might expect from someone who was drunk.:suspect:

Kulverstukas

1st Jun 2017, 05:25

31/05/17 Investigation officially announced finished by RIAN and reoublished lot of other news agencies, citing Defense ministry. Cause - crew fatigue. (I found no Defense press-release published yet except the leak I posted yesterday).

Announced at 22:00MSK 31/05/2017 at Zvezda TV (Defense ministry channel) https://tvzvezda.ru/news/vstrane_i_mire/content/201705312152-tnmr.htm

atakacs

1st Jun 2017, 05:30

Hmm

Do we have toxicology report for crew?

Did they fly previous rotations that day (would be surprised given the circumstances but one never knows)

Kulverstukas

1st Jun 2017, 05:48

1) Definitely and nothing suspicious was discovered
2) Officially they has a day off but whether they used it for proper rest or to settle their own affairs (it was daytime before night flight, don't forget) is unclear.

PS: Officially it was not regular, but "training flight".

Midland 331

1st Jun 2017, 11:04

Does anyone else see similarities with the loss of G ARPI?

- Over-dominant P1, break-down of CRM

- PF incapacitation not recognised quickly (and/or challenged)?

- No hope of recovery at the critical phase of flight.

- Aircraft particularly intolerant of poor low-speed handling.

Dan Winterland

1st Jun 2017, 13:01

The report mentions the somatogravic illusion. It's not a human error, it's a human limitation arising from the fact the human body has not evolved to cope with the sustained acceleration achieved by mechanical transport. It's more common than you would think and a real killer. As it's a function of the acceleration rate, it can affect both pilots equally.

Machinbird

1st Jun 2017, 13:33

Do we have toxicology report for crew?1) Definitely and nothing suspicious was discovered.Comment: It is my understanding that one of the decomposition products of human tissues is ethyl alcohol. Given the time to recover and identify remains, it is very likely that decomposition of the samples was at an advanced stage, and that no meaningful conclusions could be made with regard to possible alcohol consumption prior to death.

Kulverstukas

1st Jun 2017, 15:05

The report mentions the somatogravic illusion.

No it don't. It's some journalist interpretation. Also please note that there is NO official reports yet, only leaked letter.

Kulverstukas

1st Jun 2017, 15:06

Comment: It is my understanding that one of the decomposition products of human tissues is ethyl alcohol. Given the time to recover and identify remains, it is very likely that decomposition of the samples was at an advanced stage, and that no meaningful conclusions could be made with regard to possible alcohol consumption prior to death.

IIRC PIC was one of the first bodies recovered

Chronus

1st Jun 2017, 18:20

Kulver says nothing suspicious was discovered to suggest captain may have been under the influence of drugs or alcohol or a combination of both, but given that this was an aircraft and not a Akula class sub, has an intentional act been considered and totally ruled out.

up_down_n_out

1st Jun 2017, 20:40

This whole thing has echoes of Perm, Kazan and Jaroslavl all "rolled" into one.

He even came close to inverting the whole shabang before it became a submarine.
Only the Perm numpty managed to pull off that trick,while neatly jumping the transib.

More's the point most of the time the A/C were perfect working models with nothing wrong.

guadaMB

2nd Jun 2017, 14:20

The theory of a drunk PIC is a bit difficult to digest, IMHO...:rolleyes:
The AC was making a STOP to refuel.
@Kulvestukas ensured no extra cargo and no extra pax were loaded except FUEL.
The crew was piloting from Moscow and the procedure seemed to be under regular conditions. If any (or two, or the three) were drunk, things could be difficult to make a night flight under such conditions (first leg).
If the PIC (or another crew member, or all) went "wet" during the stop at Sochi, could make it possible, but apparently the nav was on duty and acting correctly.
Some old leak also told us the FO said (in a correct manner) the PIC something like: "we're falling, commander" (this read in this thread, months ago).
So it's left the PIC alone to be drunk.
Drunk enough to make a flyable AC go south? And the other two crew members went lambishly to death knowing the PIC was intoxicated? Were there any clues in the cockpit or ATC recordings to show a displeasure behaviour, this meaning something suspicious in the PIC's voice?