The flightcrew of the Polish air force Tupolev Tu-154M that crashed at Smolensk, Russia on 10 April had ignored repeated warnings that the visibility in fog was well below minimums for the approach, according to an initial factual report released by the Russian Interstate Aviation Committee (MAK).
There was nothing wrong with the aircraft, its engines or the navigation aids at Smolensk North aerodrome, the report says.
The accident was a tragedy for Poland because the flight was carrying President Lech Kaczynski and a large delegation of senior figures from the country's government and institutions, to attend a remembrance ceremony for Polish lives lost in the Katyn massacre at the end of the Second World War. All 96 people on board were killed when the aircraft hit trees on the approach and crashed.
The report says that the cockpit door was open at the time of the crash, and that there were two non-crew people on the flightdeck, one of whom has been identified but is not named in the report.
Despite being warned that the 400m (1,311ft) horizontal and 50m vertical visibility was insufficient to land, the Tu-154 crew requested permission to carry out a trial approach to the decision height of 100m, and was cleared to do this.
The type of approach guidance the crew used is not stated in the report, but a trial flight on the same route three days before had found the airport's precision approach radar serviceable, and the weather minimums provided to the crew on the day would have been appropriate for precision approach radar.
The report says the approach was initiated with autopilot and autothrottle engaged. There was a "pull up" warning from the terrain awareness warning system 18s before the aircraft's first collision with an obstacle, and the pilot initiated a go-around just before impact with a tree at 8m height about 1,200m from the runway threshold. The aircraft then suffered more damage from trees and the fuselage hit the ground inverted.