dvv

20m? Interesting… It looks very much like the TCH for RWY26…

EMIT

Just started reading this thread, overall it is kept fairly clean of sensationalism.
Translations provided by Alice seem pretty good, Here and there a couple of question marks point to lack routine with respect to aeronautical matters, that’s all.

From some of the initial posts, the exclamation “what, on autopilot, without ILS?”
Yes, it is possible to fly any approach with autopilot on, only the landing has to be made manually. (Autoland is only possible on an autoland approved ILS approach). Modes used could be (the equivalent of) Heading Select or Lateral Nav for track following and Vertical Speed for descent. As stated before, baro altimeter to be used for managing the vertical profile, radio altimeter not (although of course it will be on continuously).

Also from somewhere in the beginning: “what effect would radio altitude have on autothrottle?” Nothing. Only in case of autocoupled ILS approach followed by autoland, will radio altitude have influence (pull back thrust during flare maneuver).

(I don’t fly Tu 154, but some autopilot basics are universal).

In sound bites from radio or TV interviews, it is very hard to know exactly what was meant, by interviewer and interviewee.
Example – around post #75, Question - about the “warnings” were they based on Baro or Radio altitude?
Well, EnhancedGPWS uses True Altitude (=GPS) plus position and GPWS uses Radio Altitude (and rate) and both provide WARNINGS, or was it solely the “warning” related to the alleged Russian procedure to set a Radio Decision Height even for a non-precision approach?
So what did the investigator mean with his answer that radio altitude seemed to be involved?
(I know my quotes are not literal, just meant to convey the idea).

So, overall, like said by many before, don’t jump to conclusion too quickly, but in general, let the translations keep flowing.

ARRAKIS

Well, from what I understand, they have to set that DH on RA regardles of the kind of approach they are doing.

During their approach to Smolensk, they should have used barometric altitude and barometric altimeters and not the radar altimeter.

Arrakis

Alice025

Asked Amelin got a reply.
1./ His original map of heights is not his and is not from paper topography Smolensk data. Those detailed topographic heights' maps are still national secret LOL. Honest, in 1950-s they secreted them all, and these are issued on state demand/order to "those trusted to be knowing" only. So, sorry, Russia and her topography are still loaded with surprises :o)

2./Surprises aren't big; on seeing his map and MAK's map differ greatly btw 1,100m and 1,300m away off from the runway, Amelin went to the place and crawled it in various directions :o), taking photos down from the local hills and all, trying to figure out real angles and bends and heights. Got confused, can be this can be that. Still, vaguely thinks his original map of heights is better. But can't prove it.

3./ His map of heights he took at another forum of inquisitive minds, intellectuals bothering about this and that, and when he saw the MAK map differs, went back to them after explanations - where was their map from.
Answer: Shuttle Radar Topographic Mission SRTM, what shuttle did in Feb 2000, with the help of 2 radio-location sensors SIR-C and X-SAR that the shuttle carried on board. Result of that flight is a digital model of Earth surface (85% of it) (Smolensk in).
NASA worked on the data obtained in 2000 for 2 yrs and came up with intermediary /preliminary version "Version 1, 2003) and final version (Version 2, Feb 2005).

There exist also two formats, in 1 "ange second net" - SRTM-1 (for the US territory) and in 3 "angle second net" (for the rest of the world) - SRTM-3.

NASA

Всего в результате съемки было получено 12 терабайт радиолокационных данных, которые в течении 2 лет проходили обработку специалистами NASA.
Данные SRTM существуют в нескольких версиях: предварительные (версия 1, 2003 г) и окончательная (версия 2, февраль 2005 г).

The shuttle radar topography mission. / Farr Tom G., Hensley Scott, Rodriguez Ernesto, Martin Jan, Kobrick Mike. // CEOS SAR Workshop. Toulouse 26-29 Oct. 1999. Noordwijk. 2000, с. 361-363.
About SRTM data and their import with the help of Arcinfo Workstation. http://gis-lab.info/qa/srtm.html


So, that's where they guys from who Amelin took his original map took it from.

What TAWS uses and MAK uses no idea.

Alice025

Correction: Amelin's source is guys from another blog who used SAS Planet who uses that Shuttle data of the year 2000 flight.

TAWS, acc. to the description of it - also uses that Shuttle data of te year 2000 flight; quote:

TAWS stands for Terrain Awareness and Warning System. It is an avionic that is installed aboard the aircraft and it makes visual and sound warnings if detects that the aircraft is in a dangerous path towards terrain.
It bases his alerts on a GPS Receiver to retrieve position and other navigation information. It uses DAFIF to identify airports/runways and SRTM 3 as terrain database
__________

From which Amelin concluded that TAWS on board Polish airplane when it was screaming Terrain Pull up and etc. - was using the same SRTM-3 and therefore the Polish plane idea of the terrain will be equal Amelin's original map (that uses SAS planet that uses SRTM-3).

So, Amelin is in accord with the Polish plane.
But MAK isn't.

MAK's map differs - and Amelin believes MAK's is original paper secret Russian.

The question is :o)))) which is exact - shuttle's 2000 (TAWS, SAS Planet, Amelin mapping) OR MAK's own.

Alice025

http://s54.radikal.ru/i146/1005/37/2766f125873e.jpg

Amelin writes at 1,100m away off from the runway the difference btw 2 maps is 20 meters, and at 1,300m away off from the runway the difference is already nearly 40 metres.
About the height from the sea level of the runway itself both sources (MAK and shuttle) though agree. At least, something.
So, how deep is the hole in its deepest point is a mystery.

Alice025

PS Just in case - nobody excavated any holes in that ravine, all, how to say, grown over with trees, old as hills.

probes

Well, it's as crazy as a thing can get? A ravine should be an easy thing to get the 'measurements'?? and that 3-4m (the top of the birch tree) should make the difference btw life and death for people on a TU...

deefer dog

Arrikas, thank you for your valued contribution to this thread....

I appreciate that it is still the practice in Russia to land using QFE as a reference rather than QNH which has of late been adopted by most other nations. It may be argued that the advantages of one are half a dozen, and the other has benefits of six, but provided one is aware of the procedural differences and the reference being used at the time, I accept that there is little difference between the two. Either wy I am sure that the crew in question were familiar with both methods.

Irrespective of whether one carries out an approach using QFE or QNH, both references are generated by the same BAROMETRIC instrument - the Altimeter, of which there should be three available to the crew (assuming it is an aircraft equipped for RVSM)..

As has been discussed, in the case of a non precision approach (which was apparently being conducted at the time) the primary aid in respect of vertical navigation with which to judge the minimum descent altitude (QNH approach) or minimum descent height (QFE approach) should ONLY be a barometric Altimeter, and not a RAD ALT indication.. The reasons for this are now perhaps clear for all to understand.

Regarding the quotation above, am I to understand that despite a recent avionics upgrade, the aircraft had no means of alerting the crew when a specific BAROMETRIC height (QFE) or altitude (QNH) was reached during the descent? Are you therefore stating that the only means of alerting the crew to DA or DH was by means of on a pre-set Rad Alt indication and alarm?

Ptkay

Alice, once again thank you for your support.

It is very interesting, how MAK will explain the difference
in the depth of the ravine.

chuks

If you are doing a normal Category I ILS approach, flown to a DA (decision altitude) of 200 feet above threshold elevation with QNH set (for example, threshold elevation 190 feet AMSL [Above Mean Sea Level], DA 390 feet barometric altitude for a DH [decision height] of 200 feet), then you may well set the "bug" on the radar altimeter to "200" for an additional alert to reaching your DH. That radar altitude of 200 feet is not actually part of the Cat I ILS but just an additional thing you may wish to use, if it is available.

Approaching over uneven terrain the RA will, of course, be fluctuating and so not be of much practical use.

ARRAKIS

If you look at the cockpit pictures, you will see, that PIC himself has 4 altitude/height indictators. There is one RA (in m), there is one standard barometric altimeter (below RA). Left to it, there is an electronic barometric altimeter (ft, m, mmHg, kPa - whatever you want) and right to it there is another altitude indicator which I don't know. My guess, it was part of the upgrade and is used to input QNH to the FMS system (so, another barometric?). If someone could help identify it? QFE setting for approach/landing and QNH for FMS.
It's just the beginning of the list.

As we already know, TAWS generated no less than 20 aural warnings, but Smolensk airbase is not in the database, so no TCF. We don't know, what kind of information was feeded to the system (FMS / TAWS), how it was connected to the original Russian avionics, and how the crew was trained to use it.

Arrakis

BOAC

This whole discussion of Rad Alt involvement is a waste of time. Rad Alt DH's are NEVER used for anything other than a Cat II or III approach UNLESS they are published for a different aproach, and that would NOT be the case in Smolensk. It would be utter madness, perhaps SUICIDE would be a better description, to use it on that approach . I have only seen 2 or 3 airfields in Europe where a rad alt DH is even published for Cat I

Also the 'depth of the ravine' is a waste of time too. It matters not whether it was 100 m deep, 20 m deep or 1000m deep. THEY SHOULD NOT HAVE BEEN THERE.

I still believe it was case of a mistaken visual acquisition - building or road lights or whatever - that caused the increase in rate of descent into the wrong place. As to why they even tried, heaven only knows.

ARRAKIS

They were counting from 100 m down to 20 m (voice recorder). On RA. You can call it the way you want, but it was confirmed yesterday by the head of the Polish investigation body.

Alice,
thank you for your information. I saw that someone on Smolensk forum published yesterday a small topo map. There is a 180 m area on that map in the valley, but it looks like its left to the flight path.

Arrakis

dvv

BOAC, I don't see much harm in trying. With a fast changing weather, it's only natural to try to fly down to minima and see how it goes. And it doesn't look like I'm the only one — I readily remember a couple of cases like that when I was a passenger on a commercial flight: a Comair into KDCA (holding for about an hour, making three landing attempts down to minima in the process, then diverting due to low fuel) and whoever was flying regional for Continental into KEWR (they landed on the second attempt). Of course, the key here is flying to minima (i.e. by the book) and not „let's see if we can make it to TCH and land from there”.

ARRAKIS

There was a video recorder onboard, allowing to record outside view and to display it in the president's cabin
Interesting. Did it survive the crash or no?

YouTube - Tu 154M 101-go around

Arrakis

vovachan

With the important general present in the cockpit I expect there could be some confusion abt who was calling the shots. Who was actually supposed to give the go-around order? As a result of which no-one did ((

MartinS

With the chief of the air force in the cockpit until the very end, obviously busting minimums was done with (at the very least) the implicit permission of the highest authority, if not at the request of the higest authority. Even if the "buck stops" with the captain, he was under immense pressure with the chief of the airforce behind his back. The structure of military aviation in Poland is fundamentally flawed, and this is not the first crash to prove it. Hopefully the price of this one was high enough to warrant fundamental changes. There is already talk of leasing two LOT Embraer 175's for government use in the near future, with LOT crews.

mbar

That's right:

TBSC

Skyliner - aviation news & more

"This ERJ-175 (along with SP-LIH to be painted soon) will be operated by LOT exclusively on VIP duties on behalf of Ministry of Defence in Republic of Poland livery and crewed by LOT."