Johns:
Either way it smells of CFIT during the approach phase and might be one of those deals where they go just a little lower and lower trying to find the runway.
Quite possible.
Hard to believe that aircraft didn't have a radar alt/EGWS....but all that could be ignored and or warnings turned off.
See CASA accident report linked above.
Rather impossible in this case, but see also the "valley" on approach path
discussion few posts before. EGWS reacted, but to fast, to late.
I also wonder about altimeter settings, if there is a diff between Poland and Russia....
ICAO, including Poland uses QNH, Russia and Russian trained military QFE.
When doing my training with ex military CFI, he insisted for QFE,
I had to rethink and learn flying QNH.
The last but not to be disregarded possibility is sabotage...given why they plane was to be there, to basicaly get an apology from Stalinist era communists..
Please, do not even mention such possibility. It would have been the ultimate
disaster in Polish-Russian relations.