The first (outer) NDB was 6km instead of 4 km from the runway in Smoleńsk.
So after flying 4 km from the outer NDB they expected to be over the runway,
although the haven't found or got the inner (second) NDB marker.
The firat impact and 0m altimeter was 4 km from the first NDB.
So they might have expected to be over the runway there.
Also bear in mind, that due to the ravine the RA readings just
few seconds before were 100m or more, quite confusing...