Since this airport would undoubtedly be used by foreigners for this special occasion maybe the pilot thought the airport had it.
You don't assume anything. You have charts, and you plan your approach before you take off.
The gunshot clip from earlier.
youtube.com/watch?v=-v59q5Vyp8o
Obviously clearing up, but still way too low for an NDB approach.
This shows some pretty thick soup as well.
Also how long did it take for the Polish journalists to get to the crash site after the crash?
No clue, but they were in Katyn, so they probably had access to a window. Are there any reports by Polish eye witnesses that the weather was good?