Polish President and wife killed in Tu-154 crash

[Peter_K]

Clear to me Vanghell. The high AoA would be a good explanation. With you on that.

Another question from a non-pilot to the experts here. As a pilot, wouldn't you make yourself familiar with the environment of the destination airport before or during the flight? And if so, wouldn't they know about the 'valley' (I'd rather call it a small depression) just prior to the runway? Or would the Jeppesen maps used for the approach typically only highlight large obstacles?
This said, I believe that the same pilot flew the prime minister to Smolensk just days before the accident.

Yes, the same crew has been there just 3 days earlier with the official delegation and apparently flew there several times in the past years. Mind you, the conditions were much better allowing for something that could be called a semi VFR approach. In that case they would have been looking out front perhaps without even noticing the valley bellow just as it can not be distinguished on the satellite pictures. I saw the approach plate for the airport, if you can call it that. Very little information, it doesn't mention the differences in the terrain elevation ahead of the runway threshold, of course approach plates concentrate on obstacles, not depressions. One should not descend bellow the runway elevation.

[Evan]

One should not descend bellow the runway elevation.

Perhaps under the stress, they were mixing up AGL with AFE altitude. I don't know about the pilots experience with radar altimeters. I think they are rather rare on the TU-154.

If there was truly no comm in the last minutes, I've also considered the surface weather conditions hovering around freezing. If they picked up ice coming through the final descent, they might have got some stall buffet and were forced to decrease AoA/increase sink rate to avoid stall, thus dropping below the "glideslope", and couldn't get power on soon enough to clear the rise preceding the runway. It they were dealing with something like that, they probably wouldn't be responding to ATC warnings. But I suppose the CVR would reveal that... also, witnesses would have heard the engines spool up and nothing like that has been reported in the press.

Do you actually have a plate for this aerodrome?

[Gabriel]

Maybe I'm splitting hairs, but please stop saying that they descended below the glide slope. It was a non-precision approach in solid fog, so there was no glide slope to follow, be it ILS (instrument landing system) or visual.

In non-precision approaches you fly steps: past this point you are allowed to descend (as quick as you want) to this altitude and stay there until you pass this other point and are allowed to descend even more to this altitude and stay there, and so on. After the last point you are allowed to descend to the minimum descent altitude (MDA) and stay there until you either see the runway and land or reach the point of go-around.

With GPS non-precision approaches, there are GPS systems that coupled with the FMS can generate a 3D navigation that emulates a glide-slope of constant angle, to guide you as to reach the decision point exactly when you reach the MDA. While this approach is flown similarly to a precision approach, the minimums are still those of the original non-precision approach. But anyway I very much doubt that this airport has a GPS approach or that this airplane was equipped with this modern GPS/FMS.

And still, even if they were following a glide slope (and I'm quite sure they weren't) the real problem is not that they went below the glide slope, but that they went some 400ft below the minimum altitude that they were allowed to descend without seeing the runway. Even if you are flying a precision approach with a glide slope and even if you follow the glide slope perfectly, you are neither supposed nor allowed to descend below the decision altitude unless you have the runway in sight.

[Gabriel]

I saw the approach plate for the airport, if you can call it that.

Please a link, post a photo, or something! I want to see it too.

[Evan]

Maybe I'm splitting hairs, but please stop saying that they descended below the glide slope. It was a non-precision approach in solid fog, so there was no glide slope to follow, be it ILS (instrument landing system) or visual.

Hence the quotation marks around the word. I guess irony is out of fashion.

And still, even if they were following a glide slope (and I'm quite sure they weren't) the real problem is not that they went below the glide slope, but that they went some 400ft below the minimum altitude that they were allowed to descend without seeing the runway. Even if you are flying a precision approach with a glide slope and even if you follow the glide slope perfectly, you are neither supposed nor allowed to descend below the decision altitude unless you have the runway in sight.

Under those conditions, how are you going to expect to have the runway in sight unless you are low on the approach, below MDA. My point is, this was a non-standard approach to begin with, executed out of pressure I'm fairly certain, so the rules really don't apply. Suicide missions have their own rules.

[Evan]

Gabriel, let me ask you this:

If you absolutely HAD to execute this landing, and the standard VFR approach obviously isn't going to work, how would you go about it?

[Gabriel]

Hence the quotation marks around the word. I guess irony is out of fashion.

I had not seen your post yet when I posted mine, so it was not in response to you. In fact, it was just a general comment aimed at none in particular because "descended below the glide slope" was used over and over in this thread (including today by other than you).

The bottom line is that what they busted was not a glide slope but the MDA which is a flat floor you should not trespass unless you see the runway.

Under those conditions, how are you going to expect to have the runway in sight unless you are low on the approach, below MDA (and below the runway, how are you supposed to spot a runway from beneath?). My point is, this was a non-standard approach to begin with, executed out of pressure I'm fairly certain, so the rules really don't apply. Suicide missions have their own rules.

Exactly. You are supposed not to even try that.
(my comment added in bold)

[Gabriel]

Gabriel, let me ask you this:

If you absolutely HAD to execute this landing, and the standard VFR approach obviously isn't going to work, how would you go about it?

That's a tough question because "I wouldn't" doesn't work with "absolutely HAD", but let's play.

- I'd check with the tower the QNH when in final, in case there was some pressure drift.
- I'd check and double check the altimeter settings, and airport elevation, and make sure that wer are talking about QNH and not QFE.
- From the posision of the NDB antena, it looks like it was the MAP. I''d descend to the MDA short of the NDB/MAP and, when crossing over it, I'd start a 700 fpm descent (typical vaule for a precision approach).
- I'd have a second "own" minimum, never below 200ft AGL (typical for precision approaches).
- The moment I'm below 200ft AGL (or the RadALt goes below 200ft) and haven't seen the runway, Mr President you are screwed and I am a coward and fired but alive. I ain't landing. Or do you really want me to say how would I fly the plane to 0 ft AGL with no visual contact of the ground???? Where is the limit where I can say STOP?
- Ok. If a gun was put against my head to go on until we either land or crash, and I had the strong feeling that it was going to be used if I refuse (which would be really stupid to kill the pilot with the plane at 200ft AGL and descending in solid fog) I'd go on with the 700fpm descent hoping for the best and accepting that it was my fate that I was going to die today, be it from a bullet or a plane crash.

Satisfied?

[Gabriel]

Oh, Evan. By the way. I lack an instruments rating.

[Evan]

Satisfied?

No, because you still haven't told me how you would find the runway early enough. Let's say you have a horizontal visibility to runway illumination of about 1500 ft (assuming there are runway lights at this Mickey Mouse airport). Is it possible, given the pilot's military experience, that they intended to get in low and contour the terrain at 200AGL until sighting the runway? This is where I see the terrain issue catching them off-guard, especially if their previous visit(s) to this strip were from the opposite orientation. And especially if the plates for the aerodrome lack that information, if they exist at all. They maintained 200AGL (RA) through the shallow ravine and then the ground came up on them.

Before they arrived a YAK-40 had made the landing successfully. That set the precedent. Typically, fog does not intensify as the day develops, but rather burns off. Then a IL-76 had abandoned the approach. That set another precedent. In the mentality expressed by Kaczynski over the past incident, the YAK-40 was piloted by courageous, capable pilots and the IL-76 was piloted by weak and fearful civilian aviators. I've lived in the slavic world and I understand the mentality behind this. There's a certain headlong bravado involved in heroism that is the measure of a man. American pilots would lack the nerve. These pilots, having suffered the insult of cowardice in the past, were probably determined to prove themselves to be as capable as the YAK pilots. This is all conditioning that influences judgment, and no actual demand to land must be issued for it to take effect. But I can also imagine that one of these officials, having learned of the IL-76's failure, impressed upon the crew the necessity of the mission. Kaczynski was a very unpopular leader, and his political survival probably depended upon not showing an undue concern for his personal safety to prevent him from attending the ceremony.

I know, it's a suicidal risk, and it seems to go against logic and professionalism, but that is a western mentality and there are more powerful forces at work here than logic and professionalism.

[Gabriel]

Evan,

1- You can't find the runway early enough if the visibility is so poor that you fly into smoothly raising terrain without seeing it early enough.

2- The lowest part of the ravine isn't 200ft below the first tree impact mark.

3- That first impact is on a small tree at a height of 8m above the ground (and about 150ft above the bottom of the ravine), just at the side of the ADF antena (which I assume is the MAP). Even if you want to bust minimums and blind scud run for the runway, there is no reason to do so before that point.

4- I strongly recomend that you read this unofficial report here. Use google to translate the site. I did and it's full of factual infromation including a top and side view of both the airplane path (determined by the impacted trees) and the terrain profile.
http://smolensk.ws/blog/168.html (go page 3)

So Ok, how do you suggest to fly this approach in those conditions in a way to minimize the chances that you kill yourself.

[3WE]

The discussion has a certain irony.

The "average" ILS will take you to 200 feet above the runway (which may or may not be 200 ft AGL) and with 1/2 mile visibility you should simply see a somewhat fuzzy, but otherwise identifiable runway and land normally

Then there is the Cat II ILS where you typcialy get 100 ft above the runway and 1/4 mile of visibility....and again, land visually.

So, if you somehow thought you could accurately descend to NEAR the runway (perhaps I should say very accurately descend to very near the runway), THEN there is no need for super-human landing skills and no need to go below the runway altitude.

I'm finding this discussion that they delibaraely and knowingly descended below the field altitudue troubling.

I guess there are always "stupid moments" where I guess they could have had visual ground conact and been ignorant of terrain, or that they locked on the Radalt and ignored the MSL altitude...but it's hard to imagine folks knowingly flying around below the runway altitude in any sort of premeditated fashion...even with the president breathing down their neck.

[Gabriel]

This accident resembles a lot to this other accident in Argentina:

http://aviation-safety.net/database/record.php?id=19880612-0

An MD-80 was making a VOR-DME approach (which is about as good a non-precision approach as it gets, and much better than an NDB approach supposedly flown here).

The crew decided to descend to 100 ft AGL (visibility was about 300ft in fog). At a point the NFP, who was monitoring the VOR indication, told the FP to turn a little to the left to go back on track. The FP banked the plane to the left and the left wing impacted the 80ft trees they were skimming. While the first impacts were "soft" they were strong enough to detach several slat segments. The asymmetric lift was strong enough that the airplane, in just 100 ft AGL, rolled inverted before fully impacting the ground.

[Myndee]

I am still having a very hard time understanding why this plane was not diverted. I know all about the alleged order to land, but isn't it a pilot's #1 duty to make sure passengers get from A to B safely? Sure, the man would have likely been demoted because those that ordered him to land wouldn't have known that they would certainly have died had he not refused, so no appreciation would be given to the pilot. I'm sure there would have been some kind of public outcry and the pilot may have been vindicated (not sure how politics work there.)

He knew he couldn't do it, as evidenced by the previous attempts. I would really like to hear the CVR...but I'm sure it will be conveniently "destroyed" or "yield unusable data."

[VANGHELL]

A clarification!

The talk about the pilots going under runway elevation, is somewhat unfounded. I personally would find it quite improbable, not to say outright impossible, to do that! A trained pilot, handling VIP's at this level, is not, under any circumstances going to put his life in danger, and others' around him to try to make an approach he/she doesn't feel comfortable with.

Just to put things into perspective on this point:

1. As far as my understanding of the incident goes there was a wave of fog about 8 km thick (weather conditions: 07:00Z (10am) Temp 1°C Dew 1°C Humidity 98% QNH 1026 hPa Visibility 0.5 kilometers Winds SE 10.8 km/h / Heavy Fog), thus resulting in CAT III ILS landing conditions. I have been in the cockpit of an airbus a 318 in such an approach and landing, and hearing the GPWS saying 100, 50, 40, 30, 20, 10 (retard), seeing the runway at this point, 5, and landing on autoland, is quite an unnerving experience, to say the least. The pilot's workload, even on a fully automated approach is extremely high.

2. How in God's name do you reckon someone, would, under such conditions try to do a semi-visual approach? It would be out of the question.

3. Mind you, it was a presidential airplane, and it had all the gismos, and knobs, and newest tech available for this type of airplane. THAT includes: GPS, ILS, weather radar, GPWS and whatnot...

4. The runway is very short at Smolensk! No one in his right mind would execute a shallow approach and miss the TDZ (because he was looking for the runway), and then deploy reversers, and stop within 2,5 km (the actual runway length at XUBS)! Landing distance of a TU 154:7874 ft=2400 m (the runway length is just 2,5 km <2500m>)!!!!!!!!!! Do you gyus see a problem? or is it just me?

Now, please, do the math!!!!!