To stick to facts I will try to sum up a little what the Polish and
Russian media are reporting (witness, briefings):
1. the ac was on approach way to low, on the "antenna", as described
by one witness (probably NDB), instead of 60m they crossed at 8m alt.
It has been not confirmed, that they hit the antenna. They ignored the
ATC (PAR???) orders to pull up. The a/c banked.
2. They then hit a 8m tall tree, clipped it with the wing, lost half of the wing,
eventually hit the ground and disintegrated.
3. Experienced pilots knowing the airfield comment, that the approach is "tricky"
because of the "invisibly" climbing terrain. Shortly before the NDB there is
a gentle slope of a valley app. 40-80m deep. (Compare the google map with
the net of traversing roads on this "slope").
From here on, my speculations:
4. When in doubt about PAR directions to pull up and about the altitude
readings of GPS and ALT, they may have used the radar altimeter readings.
Those showing them the bottom of the valley instead of alt. above threshold.
5. When the altimeter reading started to rise quickly, it was too late.
6. It is possible the approach maps were not precise or non existing.
It is a Russian military AF Base, so some data could be classified.
And now the question:
Why were they too low and ignored the pull up orders (which is fact)?
The possibilities are:
1. Following altimeter readings of the valley,
2. Some kind of engine malfunction and loss of thrust,
3. Controls malfunction.
As I mentioned before the Soloviev engines did malfunction before,
taking into consideration their position, uncontained failure
meaning also possible tail controls failure.
It happened before, see my earlier posts.