RegDep

Thank you dvv.

With "they" I was referring to coordinates that are of a dubious origin in your previous message.

As to RSBN, other sources in this thread have said it was not available. I was just wondering if you knew differently, as you referred to it in your post #761.

Thank you for your help.

Reg

dvv

And one more thing — from the released CVR transcript, it does seem that the Tupolev crew used GPS to monitor their progress towards the turn to final („the 4th turn”). Which is not too bad, as they, as the transcript goes, certainly had their ADFs tuned to the right frequencies and had enough room to align the flightpath with the LOM-LMM-threshold line using that nifty dual-needle ADF dial. And there's no indication whatsoever that they had the misalignment problem the alleged interview refers to.

BOAC

From what I have seen translated, yes they were 'idiots' as dvv says, and to appear to be flying to some nebulous point on an airfield in bad weather using some blackbox wizardry with reliable ADF needles pointing off to the side....................................sheer madness - if that indeed is what was said.

The 259/261 business is totally irrelevant and already explained on this thread.

RegDep

Gentlemen: Point taken.

And the 261/259 reference was only meant relevant as a "header" of the "new" (undated) chart that Arrakis had brought up, as he was asked to.

Azrael229

I could translate the interview if that would really help (I'm in fact translator by educaton), but it's quite a lot of work and won't help much n my opinion. It's publshed by public newspaper, hence it was directed at general public and even if the actual nterview included technical information and relevant facts we won't be able to get much out of it. The only interesting fact is that clearance to 50 metres, and that could be contributing in a sense that the crew shouldn't be getting clearance that is irrelevant due to other minima, but it does not move the blame from the crew in any way.
The fact is it is now much more of political matter then aeronautics matter and this will inevitably produce lots of media clutter, can't help it.

Just to give you perspective. Jak-40 crew from 36. regiment landed some time after the crash at one military airfield in Poland, before ATC even came to work!!!!! This is the sort of practise they teach them there. Every pilot I know including MIG ones says it's nuts.

RegDep

Azrael229 - Great to have you around. From my point of view, I don't think that we need a more exact translation for now. I think your assessment is pretty good!

BOAC

Azrael - yes welcome to the thread - I'm sure you will prove very useful indeed.

Regarding this supposed '50m' clearance - that is not far away from a 'western' CatI limit of 200ft so would not be out of the question for an approach using an accurate GPS or RNav system. It should, however, be remembered that this will be a BARO minimum.

We do not know
a) What sort of approach they were flying
b) What the limits for that particular approach would be for the PAF TU
c) I'm not even sure that we have established the precise capability of the TU in this respect?

Azrael229

They probably don't have any special procedures or minima. It's unique type in the PLAF so they probably use civilian minima and old LOT procedures for these, updated to modern standards ad hoc.

I saw a post on one polish forum by AF pilot recently about procedures and standards for civilian airspace and he said there they simply got an order that from certain date they have to fly according to ICAO and other regulations. No special training, just were ordered. Probably crews from 36th regiment have more training on-on-the-job by virtue of what they do most of he time then combat pilots but it all seems a sad image. (I must admit from observation though - as I live on EPWA approach path - that polish F16's do practise flying in civil controlled airspace on regular schedule - which I can clearly hear and see , but this is irrelevant here for sure)

Anyway - I am not professional in flying but happy to help with any Polish language materials for this thread.

dvv

BOAC, I really doubt there was a clearance to descend to 50m. If there were one, it would've been registered on the CVR track that was written directly from the radio, and it hardly could have been unintelligible. Besides, it doesn't correspond to any procedures either on the field charts or even in the Tupolev manual. So until/unless we have a confirmation of such a clearance from the MAK, we can safely dismiss it as an unsubstantiated rumor.

Azrael229

What is probably relevant to this discussion is the information published couple of weeks ago that specialists in Poland managed to read much more of cabin recorder and there are works in progress on much fuller transcript. Unfortunately we don't know when this may be published and I wouldn't be expecting it very soon.

BOAC

Absolutely - I was not suggesting there had been such minima for the reasons you state, just that it would not have been unrealistic for a suitably equipped a/c - in any case, ATC do not issue 'minima' to approaching a/c as we know.

It is just another bit of confusion being thrown in for reasons I cannot understand - again not relevant to the crash. Can anyone remind me why we are talking about it?

RegDep

It was discussed in the news article that we now have written off.

ARRAKIS

Tu-154M FM page with minima list for different approaches.
minima-Tu-154M.jpg - Rozmiar oryginalny - Fotosik.pl

Even, if we don't know for sure the particular approach that was used, we can assume that the minima for the aircraft would have been between 100/1200 and 120/1800 m.
The former commander of the 36th regiment was talking a few times about 120/1800, which would mean an 2xNDB approach ("OСП"). I'm not 100% sure what should be the minima for the "OСП+РСП" approach (2xNDB plus an additional limited control from the ground). The same as for 2xNDB?

What we know for sure, in any case the weather was way below the minima.

Arrakis

BOAC

"Paging Azrael Paging Azrael"

ARRAKIS - it is not much use posting that on an English forum, is it?

ARRAKIS

Personally, I always prefer having access to source documents thus, I posted that page for anyone interested.
Key information from that page, in answer to your question, are given below. I think it's pointless to translate the entire page.

Arrakis

dvv

BOAC, it wasn't Polish, it was Russian :-) And yes, ARRAKIS reproduced all the relevant figures already. And we don't want to discuss Tu154's ILS capabilities here, now do we? ;-)

BOAC

- I've been back through his/her posts and cannot locate anything in English - can you either give me the post number OR translate please?

As one who would not know an ILS from an 'ABTOMAT-jobbie' I need some assistance. Do I deduce that the TU154 is only CATII?

Any minima for 'RNAV/GPS' known or 'not fitted'?

criss

In wx conditions from that day, there is no airport in the entire world they would have been entitled to even think about making an approach... 1 NDB or 5 NDB... this was CAT III wx, and they were not certified for it (and of course Smolens doesn't have it either).

dvv

Oh. So we are talking ILS here :-) Yes, you deduced it right — no CATIII for Tu-154. Otherwise, you can fly her down ILS using AP or FD or manually. GPS "not fitted". Well, the 101 was equipped with an FMS, and we don't really know what other mods have been made, but it's still irrelevant as there were no ILS and no GPS procedures for Smolensk North.

So. ARRAKIS just pointed out in http://www.pprune.org/rumours-news/4...ml#post5807001, that when all you have is PAR or a pair of NDBs or a combination thereof, you cannot go lower than 100-120m anyways.

Azrael229

Sorry, I do understand some Russian as we all had to learn that in school till 1990, but not enough to help with that correctly. Polish is in modified Latin alphabet not Cyrillic