Polish President and wife killed in Tu-154 crash

[Northwester]

Where did you get all this info?
Especially the "trying to pull up" and "trying to turn" parts.

From the CVR transcript. There were 3 sound alerts at F=400 Hz indicating getting out of the auto mode. They were explained by Tu-154 pilots in an analysis published in Poland.

[Gabriel]

No idea how an electrically powered altimeter works. Some kind of Klingon technology. Here's what it tells me:

UVID-15 feet altimeter. The device is not connected to the SVS (static pressure system), and has its own hotspot to set the pressure (in inches Hg) and the pressure display window. Used to set a separate pressure since in the CIS you will get the pressure in QFE (so the altimeter reads 0 at the aurport) and QNH abroad. Must be switched on separately using the switch on the overhead

Yes' I had read it in your previous post, but it doesn't say much.
And why would a non-barometric-pressure altimeter have a barometric-pressure adjustment knob?

[Gabriel]

From the CVR transcript. There were 3 sound alerts at F=400 Hz indicating getting out of the auto mode. They were explained by Tu-154 pilots in an analysis published in Poland.

The CVR transcript analyzed and explained by Tu-154 pilots?
That's too intersting to miss it!
Any link? If it's not in the net but in print, maybe you can scan it and post it? If it's on the TV, maybe you can give us a sumarized transcript?

[Evan]

Yes' I had read it in your previous post, but it doesn't say much.
And why would a non-barometric-pressure altimeter have a barometric-pressure adjustment knob?

perhaps a potentiometer simulating barometric adjustment. Perhaps Soviet sense of humor. Why feet on this one? I don't have the foggiest.

[Northwester]

...with the second pilot calling for a go-around after they had passed the decision point.

We don't know yet if the pilot said "we are leaving" or "we are doing final approach". Both expressions are one word in Polish, almost identical. And with the Russians doing the transcript, and cockpit noise, they could have missed it.

[Northwester]

The CVR transcript analyzed and explained by Tu-154 pilots?
That's too intersting to miss it!
Any link? If it's not in the net but in print, maybe you can scan it and post it? If it's on the TV, maybe you can give us a sumarized transcript?

I will see what I can do. It was printed, if I remember right.

[Northwester]

Please remember I am not "pushing" this theory or any other one. I am trying to find the most probable scenarios that can be supported by at least some facts known so far. I know that the pilots knew about the searchlights, I know there was at least one such light pointing to a patch of grass where the wheels of the plane almost touched the ground. Sure, there are big holes in this theory and it might collapse tomorrow, but at least there are some facts that support it. There are theories circulated around that have not a single fact in their favor.

Technical malfunction is still an option. Pilots error to some extent almost sure.

Again, picture of the suspect searchlight.

[Gabriel]

there was at least one such light pointing to a patch of grass where the wheels of the plane almost touched the ground

How do you get to that conclusion?

As I've said before, they hit the first tree below runway elevation, before the searchlight, and off-track.

Please refer to post #207 (I'd give the original source if I'd found it).

Be aware of the "confirmation bias".

[Evan]

- Inductive dispatching UVID-15 altimeter
- see also -
- Electromechanical altimeter UVID-15F

What is it?

I'm guessing from the word "dispatching" that this is the one that sends data to the transponder. But how does it determine altitude if not via a static port? By electromagnetic induction? By flux capacitor?

The UVID-15 altimeter uses an inductive pressure transducer.

Inductive pressure sensors are coupled with a diaphragm or a Bourdon tube. A ferromagnetic core is attached to the elastic element and has a primary and 2 secondary windings. A current is charged to the primary winding. When the core is centered then the same voltage will be induced to the two secondary windings. When the core moves with a pressure change, the voltage ratio between the two secondary windings changes. The difference between the voltages is proportional to the change in pressure.
An example of an inductive pressure sensor utilizing a diaphragm is shown below. For this kind of pressure sensor, taking Chamber 1 as the reference chamber with a reference pressure P1 coming into the chamber and the coil being charged with a reference current. When the pressure in the other chamber changes, the diagphragm moves and induces a current in the other coil, which is measured and gives a measure of the change in pressure.
These may be used with any elastic element (though, it is typically coupled with a diaphragm or a bourdon tube). The pressure reading generated will be determined by voltage calibration. Thus, the range of pressure in which this sensor may be used is determined by an associated elastic element but falls in the range of 250 Pa - 70 MPa .

I think it still must be coupled to a static pressure to function. The information I posted earlier states that is not part of the "SVS" static system.

The photo attached shows the three altimeters (on the standard TU-154). The top one is the radalt (in meters), the center one is the inductive dispatching UVID-15 altimeter (in feet), and the bottom one is the standard baro (in meters).

Confusing enough?

[guamainiac]

Gabriel: There is a marked difference between prop (non-turbine) and jet when it comes to throttle to lift times.

Honestly, take that to the bank.

This is why adherence to minimums is so much more critical in a jet. It would be nice to hear from one of the folks who are so rated.

[Evan]

This is how they sit.

Apparently, Polish TU154's normally fly without the navigator:

The crew interaction was unusual due to the introduction of the navigator. No procedures were available for that type of crew combination and interaction, as the airplane is usually flown with a 3-man cockpit (captain, first officer, engineer) and all training, documentation and manuals were set up only for a crew of three.

The navigator is apparently ШТ on the transcript (he is making all the radio calls and call backs, often in English), but the transcript key does not include a designation for 'ШТ'.

[Northwester]

When you suggest that it was either your theory or else a mechanical failure for which there is zero evidence, it does tend to sound like you're pushing your theory. I have another theory. The pilot said to himself, "We're going to put this plane down even if there's a Bolshoi rehearsal, three cows and a peasant wedding on the runway" ... once in that mindset, his judgment was impaired, and either his awareness or sense of reason were lost on the way down. However, I'm not pushing this idea on anyone either. I'm sure there are many other possible scenarios.

I never said there was zero evidence for a mechanical failure. One could easily speculate that some kind of mechanical failure occured. There is no information available NOW that would support it.

I like your sense of humor . I guess I will have to develop another theory so I am not being accused of pushing just one.

[Northwester]

The navigator is apparently ШТ on the transcript (he is making all the radio calls and call backs, often in English), but the transcript key does not include a designation for 'ШТ'.

Absolutely correct. ШТ is SHT in cyrillic and stands for "shturman", Russian for navigator.

[Northwester]

- The photo attached shows the three altimeters (on the standard TU-154). The top one is the radalt (in meters), the center one is the inductive dispatching UVID-15 altimeter (in feet), and the bottom one is the standard baro (in meters).

This is the M version. Altimeters are clearly visible.

[Gabriel]

I think it still must be coupled to a static pressure to function. The information I posted earlier states that is not connected to the "SVS" static system.

... but connected to the non-SVS static system instead.
Exactly waht I was thinking.