Any idea of accuracy of UAS TAWS data/maps for the Smolensk North approach?
Looking at the Universal Avionics web site, (they are the manufacturer of the TAWS system installed in the Tupolev) they have a list of airports that are included in the TAWS database. Smolensk is not included, therefore there would be no TAWS data or maps available to the crew.
Since no data was available, the system would degrade to a more basic Ground Proximity Warning System, and since the aircraft was set up for landing mode, a number of GPWS warnings would have been disabled to avoid nuisance alarms.