ARRAKIS

One of the reason is for sure equipment measurement inaccuracy.
That time shift is quite obvious. Why? I explained it earlier.

My 0,02$ regarding
http://www.mak.ru/russian/info/news/...m_101_pic1.jpg

As was proven by Sergiei Amielin from Smolensk forum, that terrain profile is wrong. On the profile above, 1200 m from the rwy the terrain is descending to around 190 m, which is contrary to GE, Siergiei's own measurements and Russian military topographic maps. The lowest point of the valley on the flypath is around 200 m, approx. 1700 m from the rwy. End of story.

In my opinion, the scale on the left is wrong. It should be every 10 m and not 20 m. If you switch it, MAK's profile comes close to GE, etc.. excepted the 1200 m point.
There is something else.
1100 m from the rwy on the original profile the terrain is slightly above 220 m mark. This is where the plane hit the first tree, 10.8 m from the ground and flying 15 m below the rwy elevation (according to preliminary report). That doesn't match. Obvious error.

Now, 258 m (rwy elevation from MAK's profile) -10 m - 15 m gives 233 m (on the profile)...
but
rwy edge elevation is 258 m according to MAK's profile and 253 m according to GE/Sergiei's measurements.
1100 m from the rwy the terrain is around 243 m (on MAK's profile, after switching the scale) or 237/238 m according to GE/Sergiei's measurements. In every case there is a 15 m difference between the runway and the terrain (1100 m mark).
I think the terrain 1100 m from the rwy edge lies 15 m below the rwy, which means 101 was flying approx. 5 m below rwy and not 15 m when it hit the first tree.

Arrakis

BOAC

-which is what everyone here is doing. That is what happens on this forum.-oddly, no I do not know which, oddly, is why I asked! It seems no-one else posting here does either, so what do were have here Flt simmers? Political activists? Obviously no-one who knows diddly-squat about flying a military approach in Russia. I certainly don't, but I DO know what I need to land safely.

It seems to me that 'SadPole' has accepted the most likely cause also.

Why don't you tell us why you think there was a PAR/GCA what-you-will in use?

RetiredF4

I did it already, just read my post http://www.pprune.org/5751671-post463.html . And i stated there also, that it might be some kind of PAR or it might be not. I cant make up my mind concerning that issue.
Nothing fits.

franzl

FlightDetent

BOAC: From my experience in CIS, it is very common that approaches are monitored by ATC. Even during ILS, you will be given information on distance, crosstrack and your glidepath error. DME equipment is few and far between, I clearly remember a NDB procedure to one of our destinations where for 2NDB approach the FAF was noted as "final descent point provided by approach controller". Here's one similar:


It seems that the ill fated (and executed) APCH to Smolensk was not a PAR approach; hence the resposibility for profile flown rests solely with the crew and you are indeed correct to re-itarate so.

Given the fact that in CIS final approaches are routinely monitored, controllers are trained for the task and most probably also required to issue instructions during final if the profile is incorrect (this authority does not extend over our EU registered, civilian operations still it happens so frequently) an additional safety layer exists. This is one more barrier breached during the accident. I believe that's why people with more understanding/exposure to CIS/Military ATC-to-Crew procedures keep digging at the ATC aspect so vigorously.

Yours sincerely,
FD (the un-real)

dukof

Arrakis,

I would be very interested to hear your explanation of how a time shift of any significant magnitude can exist on ATC radar display. Would you be kind to provide the link to your previous post, or to rephrase it, for the benefit of all readers? I'm sure I'm not the only one interested in it.

As for the terrain discrepencies:
Yes you are correct. The errors you talk about is in the image you provide, but has nothing to do with the plots I have posted. They take these things into account.

Both charts I posted indicate a height of flight profile at approx 5m below rwy at 1100, and terrain at about 15m. This is exactly what is also your own assumption..

Sorry, I thought you post was to point out an error in the plots I showed. But this means we agree, yes..?

vakakaaa

Russian generic approach types are listed in pictorial file: ”ApproachTypes.pdf” (sometimes loadable)...:

Рассмотрим 10 типов захода (хотя их можно придумать и больше)...

1. Заход по КГС в режиме ПСП. (typical minimum: CATI – 60x800 or 60x550)
2. Заход по КГС в директорном режиме. (CATI – 60x800 or 60x550)
3. Заход по КГС в автоматическом режиме. (depends on cat, can be CATIIIB – 0x50)
4. Заход по ОСП. (120x1500)
5. Заход по ОСП с использованием ОРЛ-А. (120x1500)
6. Заход по РСП. (Radar APP, 60x800)
7. Заход по РСП + ОСП. (60x800)
8. Заход по ОПРС. (one separate NDB) (200x2000)
9. Заход по VOR/DME. (100x1000 or 250x2500)
10. Заход визуальный. (Visual) (200x2000)

ОСП = 2 xNDB (non-directional beacons, LF/MF) (DPRM + BPRM) - 2xARK (= ADF) required.

*********
Smolensk-Severnyj (XUBS) IAC-chart RWY26 (dated 12Apr2005), most probably obsolete but gives:

ОСП РСП РМС 15п
РСБН 13н

which means there is (have been at least):
-- 2xNDB plus radar (#7 above)
-- RSBN (ch 13) for positioning in “Krug” (rectangular circuit), to be coupled with PRMG (ch 15) for precision electronic course + GP
(these both are Soviet UHF type systems now in big problems internationally as they are conflicting with mobile phones - PRMG is pure a Mil-type landing system, seldom even directly mentioned).

РМС in this case is a special way to introduce a “radiomayachnaya” landing system.
No mention in IAC chart of ОРЛ-А -- Airport Surveillance Radar (part of РСП?).

*********
Mention of “markers” in this case is hardly appropriate, since marker ground antennas seen in Amelin et al photos most probably are part of PRMG (not any “ILS” type). While with carrier fq of 75 MHz, PRMG markers are differently audio modulated: outer MKR = 3000Hz dashes, while middle MKR = 3000 Hz dots. So, using Jeppesen type LMM & LOM not very appropriate.

********
In “Stenogramma 101” the “beep sound” 845 Hz (10:39:50,2) = DPRM id (OK 310), while 800 Hz (10:40:56,0) = BPRM id (O 640).

Several typing and other errors corrected ... dont wish to interfere nice discussions in any way....

BOAC

Thank you FD, at last a useful post. In fact the procedure of monitoring and advising errors is common here as well - most self-interpreted approaches (including visuals) are routinely radar monitored, certainly in the UK, and similarly warnings would normally be issued if a major error was seen (as has happened at LGW a few times!) The problem here is that we really have no idea when precisely the 'dirty dive' happened or when the controller might have been realistically expected to recognise what was happening as an imminent accident - or merely as this apparent 'scud running' as described earlier which appears to be 'accepted'. Perhaps he was used to the heroes coming in under the crud at tree-top height? When to shout?

Alice025

The times flown btw various kilometres away, and the resulting speeds, and basically everything :o) looks of course very weird to all. The plane rushes on, then suspends :o), flies at speed 187 km/hr at which it should drop but instead it is gaining height again, cutting tree tops higher away off from the ground (like, beginning from bushes' cutting and ending up by high tree tops).
Until this technical part is published there is no way to figure out more it seems.
Possible glidepaths' charts in abundance and one looks weird-er than another.

In those computer simulators chaps do various options of those weird routes and speeds and various altimeters' application. Only one found the way I'll ask him what is it, he doesn't crash in the Northern for the second week in a row already :o) Says that "without a word from the ground and without GPS, by markers only".

Technical data is said to be promised to public in Poland after 20th when the elections will be over. Hilarious scheduling sure. But they say by normal ways MAK would only say something in half a year or in a year.

And with these political games within Poland and between Poland and Russia all is unhealthy.

FlightDetent

Spot on! There's a system with task(mission) oriented crews and mission management/asessment/control by ATC, we can call it military/Soviet style, but it works. Once you take out the ATC responsibility and authority out, the system loses one leg and all breaks down. ATC knows when to stop an approach but as this is not their authorisation under "civil/foreign" rules any longer they keep quiet too late.

Ironically, if the ATC did excercise the mil style authority (forbidding the start of the approach because of sub-minima weather, commanding a go-around once below safe profile) and the crew would have be ready to accept such, the safety layer would work.

Instead, we have landing-minded pilot with some peer pressure and less than 100% authority (sub-ordination) with no last line of defence against his errors, both unseen and intentional. Needless to say, the apparent scud-run was poorly planned, miserably executed and surely very illegal under Polish AF own procedures in first place.

Yours,
FD (the un-real)

BOAC

Yes, classic 'Polish Cheese' as they say. - out of interest, that does not make any sense to me - after all, on an beacon approach the descent point is marked. Do you think it is a failure of translation and should be "final descent clearance provided by approach controller".?

Alice025

"Let me mention my thoughts concerning pressure from the general in the cockpit. I think there was none. I´ve flown with generals myself (as instructor pilot), there is only one commanding authority in the cockpit, and a general having flown himself will respect this. Thed reason him being in the cockpit might just be due to the fact, that he liked the company of an aircrew more than the company of the presidential entourage. The CVR gives no hint at all on any kind of pressure. "

franzl, this was also discussed over yonder :o)
Many reasoned an experienced commander is only of help, as a professor, kind of, lending a helping hand in complex meteo conditions. Besides, indeed, no info that he would have "pressed", so only good and useful things could be had of his presence.

But the military pilots available there said two of them one and the same their saying: "There are no friends in the landing". "Na posadke tovarischey niet". Meaning no professors no nothing the pilot should rely on himself and everything else is wrong extra-s.

In this case - if they didn't activate go-around - which we don't know - it could be the 2nd pilot said "Go around" but did not execute it, waiting for Capt. decision (which he shouldn't do. If the capt. not answering - 2nd pilot must activate go-around. In Russia.) Waiting for Capt. decision because he knew it may be career-related landing for his Capt. /yes or no/
The Capt., in his turn, could have been waiting for the Air Force commander in this case to confirm go-around.
Thus they all waited upon each other at 100 who will say the No and time flew away.
May be.

Alice025

Anyway in this case the Commander had less flying hrs than Protasiuk!
But others reasoned that as the Commander didn't carry presidents etc to far destinations, but flew military planes, nevermind flying hrs, he'd have had far more landings.

Tagron

Alice, that is a very interesting theory. It should not happen, of course, the captain should have made that decision to go around and activated it immediately. But it could "fit". Because of the very high descent rate it is possible to view the few seconds delay as critical. In other words, indecision rather than deliberate risk taking, and perhaps lack of awareness of the significance of their descent rate. I suspect it is another question to which we may never have final answers.

BOAC

Another very strange thing about the way this crew operated is that there appears to be no communication between them below 80m apart from a radalt 'countdown' by 'Nav'. No call of 'visual' or 'I am continuing' or anything. Most unusual.

kubag

Sorry for loggin in a profi forum, but I found something about habits of Polish military pilots that no one had spotted before.
Good read:
Jak wyl?dowa? Jak-40? Specjali?ci badaj? incydent z ko?ca kwietnia - Polska - Fakty w RMF24 - naj?wie?sze wiadomo?ci

Translation:
Google T?umacz

FlightDetent

Definitely not. The configuration is beacon-locator + radar, vakakaaa describes in detail. Check the Perm plate I posted (I hope it displays correctly), the only way to fly it with ADF equipped aircraft - there's no DME installed anyhow - is to leave intermediate apch altitude when instructed by radar controller and work V/S against timing. It is not a NPA without FAF based on turn/timing. It is a radar/NDB approach.

While this technolgy is getting even more obsolete as we speak through commisioning of VOR/DMEs and GNSS procedures, I wanted to demonstrate that under classic steam gauge + blip screen system the precision controller is integral part of the final descent to land and hence why the Smolensk ATC role is being reintroduced to the debate over and over again.

BTW, there's no cleared for approach 2:30 flight time east of my base; you will be advised of your position against the final apch trajectory and instructed to continue.

Yours,
FD (the un-real)

BOAC

Your image was too small to zoom up enough, but why 'radar' is required is a mystery! It looks just like a 'standard old-fashioned NDB approach. Are you saying that the 'approved descent' might not be over the NDB? It seems bizarre to have a 2 NDB approach with a functioning precision radar following. Why on earth not just fly the PAR? Does it mean that if the radar fails you cannot fly the approach?

Even with my very 'rusty' engineering Russian, vakakaaa's post was too much to follow

Why, in Smolensk, do we not 'see' any ATC approach descent instruction on the CVR transcript?

Your last para lost me - what happens after you 'continue'?

RegDep

You can get a bit better picture from a MAK report, but in Russian
http://www.mak.ru/russian/investigat...bko_report.pdf. It is also somewhere in the English translation of this report, which you should find in the AAIB website, but I cannot get the url right now. RD

Tagron

FlightDetent, you are providing a welcome new insight into this forum. Can I confirm with you the implications of your description of the Russian procedures..

The approach is flown as a conventional NDB approach after ATC identifies the descent initiation point. The precision controller watches the glidepath but does not provide glidepath information to the pilot. He lets the pilot sort it out for himself and only intervenes to command a go-around.

The NDB approach at Smolensk North should have been flown at an average descent rate of 3.9m/s (780ft/min) from the 10km point assuming 280km/hr/140 kts. According to the analysis we have seen so far it would appear that they crossed the OM 100m too high having only achieved approx. 2m/s. Then they increased the descent rate to 6.8m/s (1350ft/min) which would have quickly corrected the profile if they readjusted their descent rate back to 3.9m/s. But they maintained this high rate for too long, and we may take a view on whether this was deliberate or inadvertent.

Throughout this apparently badly flown procedure, the controller was telling them “on glidepath”. So does “on glidepath” mean something like within a band of parameters which the controller judges to be satisfactory for a landing ? Whereas in the western world, “on glidepath” means strict adherence to a predetermined glideslope, e.g.3 degrees.

Please feel free to correct me if you think I have this wrong.

BOAC

Thank you RegDep, but I found the chart difficult to read (and the report horrific...). None of my (somewhat old - 2003) USSR 2xNDB plates have the 'ATC descent' bit.

I need to rewind here:
Where is the evidence for their being 100m high at the OM?
Where is the evidence for 6.8m/sec?

Do we have the FDR?

What if they WERE 'on glidepath' until the fatal dive into the valley?