Polish Government Tu154M crash

[robdean]

Would a TU5 or any similar sized a/c (727, 737) remain controlable at landing speed on right aileron and rudder after losing a left wingtip and aileron?

Missing an aileron means all 3 hyd. sys. are opened.
Means NO PRESSURE ---> NO CONTROL, AT ALL!!!

Presumably hydraulic pressure wouldn't go to zero instantaneously even if open circuited. The intended time to landing here was of the order of seconds. Go-around would be inadvisable...

ST27's highlighting of the leading edge slats on the Tupolev is salutory: one wing with inevitable acute lift and control impairment, many metres missing and possibly stalled by the resulting turbulence/config. The other wing maybe relatively intact and in ground effect. I begin to intuit the resulting axis of rotation...

...which still begs the question of whether a heavy jet has ever mislaid an entire aileron en route. I can't believe it's impossible, given that total hydraulic failure has been survived.

[Elberoth]

Thanks for that pic.
I couldnt tell (by going to the site) whether the photo is:
A. The accident aircraft, or its squadron partner, and
B. Before or after the December upgrades.

Does ayone have that info?

This info is down below the photo:

Aircraft Poland - Air Force
Tupolev Tu-154M - #101

Taken at
Newburgh - Stewart International (AFB) (SWF / KSWF)
USA - New York, September 24, 2008

Clearly, it represents the a/c BEFORE the Dec 2009 upgrade.

[grizzled]

Thanks Elberoth

I was unable to open that link so I appreciate your input on that.

So, we know the photo was taken before the modifications on the accident aircraft. So, if that photo is of the accident aircraft -- and not it's partner -- we still don't know the flightdeck configuration of the aircraft since December last year. Correct? Anyone have any specific info on the equipment fit / cockpit configuration from Polish sources?

Also I would be very interested to know the differences (if any) between the squadron's two 154s.

grizz

[Bahrd]

One thing is clear IMO: it is profoundly irresponsible for a politician or other public figure to threaten or criticize a pilot for exercising professional judgement in conducting a safe operation, as the Polish PM did in 2008. It is also extremely foolish, as his family and friends perhaps now understand when they are honest with themselves. Not to mention the family and friends of the other dead. I daresay a very bitter lesson has been learned about the need to comply with procedures - pretty sad.

I dare to say that even this is is not clear. The flight to Georgia took place almost two years ago.
Since then the President flew dozens of times (likely - in different weather conditions) without incidents. Since then - I'm sure - both sides (the President and the pilots) learned from that lesson.

[Ptkay]

I'm sure - both sides (the President and the pilots) learned from that lesson.

I don't think so.

The PIC on the accident flight was the FO on the flight in 2008.
He must have had a clear perception of wht was happening then,
and what kind of pressure was put after this flight on the PIC.

[Elberoth]

Also I would be very interested to know the differences (if any) between the squadron's two 154s.

The second (remaining) one is beeing upgraded right now in Russia.

[grizzled]

Elberoth

Thanks so much for your input.

So, this means that for the past 3 or 4 months the two aircraft had different equipment and configurations. Do we have any info on how many hours the crew (particularly the Captain) had on the accident aircraft since it's upgrade? And how many hours on the other aircraft since the upgrade (which, as I understand it, would equate to total time since then, as he would have been flying only those two aircraft).

grizz

[ARRAKIS]

101 made around 140 flight hours after the upgrade. The second machine is being upgraded now.

Arrakis

[MartinS]

To me, the only real question is "why were they so low?".
Form the recent Polish media reports, these pilots were known to be very "by the book" types. The idea that they were trying to duck under the fog to find the airport is absolutely unacceptable, especially that they were fairly familiar with the airport and its topography - they must have known about the valley before the runway threshold.
However, the early indications are that they were in a rush. This leaves room for mistakes, especially when using a language foreign to them for communication, perhaps they thought they were given QFE while actually it was QNH? Perhaps they misunderstood one of the digits and their mistake was not caught by the controller? The controller claims they were not fluent in Russian, especially numbers, their superiors claim the opposite. Perhaps in a rushed situation there was a misunderstanding. I am no expert here, but could someone post a likely descent profile if the wrong setting was used? Would it be at all similar to what we have seen so far reconstructed? How much of a difference is there in the QNH-QFE settings at Smolensk?

[grizzled]

MartinS

If you search this thread (using QFE and/or QNH as search terms) you'll find the answers to your questions.
Well... not the answer to "why?" of course. Hopefully the answer to that omni-important question will be answered by MAK's investigation.

[On_Finals]

Question for TU-154M pilots -- how long do the engines need to come up to full thrust from approach settings if you find yourself a bit low?

According to the AOM - 5 seconds.
According to a friend who spent 20 years as a flight engineer on the Tu5 - pretty much the same, but give a second or two depending on engine state and hours

[yaw_damper]

From 40%~12 sec. from 70% 8sec.

[Bahrd]

Ptkay - my opinion was based on the recent interviews with Lt. Grzegorz Pietruczuk (the "Georgia PIC") and Col. Grzegorz Kułakowski from 36 SPLT.
They both didn't consider "the VIP pressure" as a possible cause.
Let's wait for the official report then.

[andrasz]

I recall 8 seconds from flight idle to T/O thrust, but those were B-2s with different engines.

To me, the only real question is "why were they so low?"

To me that's just a minor detail in the full picture. The real questions still remain to be answered:
- Why was this approach commenced at all with all numbers firmly below legal minima?
- Why was the airport not formally closed, when clearly the criteria for continued safe operations were not met? (a stark contrast to the mass hysteria over Europe at present )
Plenty of speculation on both, but still no official word...

[ARRAKIS]

I think that the answer to your questions will be pressure. On both sides. Little chance someone will admit it officially.

Arrakis

[robdean]

It's needn't be brute pressure to keep the facility 'open', it could be simple diplomacy. If you have a foreign head of state overhead, on a sensitive official trip, aboard his national equivalent of 'Air Force One' (very likely a vehicle with some formal 'ambassadorial'/'embassorial' status in the circumstances), it's quite natural to gently but firmly suggest that His Excellencies' pilot accept a cordial recommendation to divert. In the event, the transaction seems to have been along the lines that 'You are warmly esteemed guests, and whilst we urge you to avoid a mindbogglingly hazardous approach, we are disinclined to cause offence by parking tanks on the runway lest you be nuts enough to continue.'

[DJ77]

From MartinS:

How much of a difference is there in the QNH-QFE settings at Smolensk?

Based on the picture in a previous post (#650), I understand that the threshold altitude is 254 m. If correct, the difference QNH - QFE is about 30 mb.

Based on this same picture, when passing abeam the inbound NDB where it struck the first obstacle, the a/c was about 85 m below the normal flight path. This can be due to a 10 mb difference in the altimeter setting relative to the real pressure.

I share the view that the real question is "why where they so low" but so far I can't believe it was intentional.

[criss]

Why was the airport not formally closed, when clearly the criteria for continued safe operations were not met?

My aerodrome is CAT with min 350m/100ft. We never closed, even with RVR 100ft. It's a decision of CPT - there's a reason why he's called pilot in command.

[PaleBlueDot]

Sorry can't find it somehow, there was a large photo and comment that the airport should cut all trees in approach. As they nearly made it, managed to get sharply up, out of the ? that hole pre-road, made it over the road, but hit the trees again the other road side. That's of course, after this tragedy, absolutely. Still, if you look at the reconstruction aerial maps, of the Smolensk chap who stubbornly works on them (it's easier for him, he is local. can take a drive, look up, after all), they were 15 metres above the road, not 2.5 m above the ground, as they started it, the lowest point, in the hole. May be not the trees on the other road side were the problem for them at that point, but that they were already half turned over, above the road.

The forum over there concluded that if not that turn over they would have made it, they gained their height, got out of the hole. And at least would have landed on the trees the other road side heavy, but not with so many casualties. And that even that they were not on the glissade but slightly leftward -their route, factually taken - the red line - was still bringing them right onto the runway, not bad course, they would do the runway.

I have written that post because spin was not pilot error, as was suggested, but merely the effect of collision with the trees and partial wing loss. Without the trees, they would have find themselves above the runaway and aligned with its left edge. Pilot would than have the chance to try landing, or to continue with climb which he started in the valley. Either way, they would probably still be OK, in spite of all previous errors. It is easy to see that they were in perfect horizontal position during the controlled part of the flight. Look at these pictures.

This one is new. Vertical fight profile aligned with satellite image from Smolensky forum:

Vertical Profile & Sat Image

At the first tree they were 4m above the ground. And a moment later maybe only 2-3m. That is completely impossible if you are not perfectly horizontal. And on picture 7, after the first serious tree collisions, here, you see that the tree cut was higher, but still horizontal. That is the tree before the first road. Pilot lost control probably moment before that, and begin to spin immediately after that. By the next road he was already inverted (picture 9).

In high-resolution satellite photo, here, we can see that the trees were not cut even exactly on the runaway axis. So, whatever errors have led to this situation, they might have had some chance even after all of them, if only the aproach was clear of high trees.

[Alice025]

I'll translate a bit, though the same was said here.

- ... using head of the policeman in the photo :o) as an object of known size, my rough estimation is the wing piece was torn off in the area of 32 "nerveure", count the length of the torn away piece yourself. The drive RP-55 is attached to that side of the aileron nearest to the wing, btw 37-38 "nerveures". Which means the drive RP-55 flew away together with the aileron and the hermeticity of all the three hydro-systems was violated. The plane became un-manageable.
- In 5 seconds a critical amount of hydro-substance through three tubes of thickness of one finger will not have time to pour out away, even at the pumps working at full capacity, and in this case this capacity was not requested as the mechanization/the wheels? were let out which means the major part of the liquid was in the tanks.
_____
I thought measurements indicated the first tree was cut at 8 m height.
Certainly saw a photo of the second tree cut, there was a measurement tape, let down off from the cut place, to the ground, and a close shot at the measure by the ground. Haven't seen such a photo, with a tape measure of the first tree, though.
_____
There are still no recordings' transcript released, in Poland, I mean. As far as it's known "around".