Group 8 Final approach and a descent on the glide slope
a. Descent on the glide path was performed with AP controlling both pitch and bank with AT engaged. Turning off the AP in the longitudinal channel and AT occurred while trying to go around 5 and 4 seconds, respectively, before the collision with an obstacle (tree), which led to the beginning of the destruction of the airframe. Disengagement of AP in the lateral channel occurred at the time of the third collision with obstacles, which led to the beginning of the destruction of the aircraft structure.
b. The first TAWS warning “PULL UP” was 18 seconds before the collision with an obstacle, which led to the beginning of the destruction of the aircraft structure. Before this, a message TERRAIN AHEAD sounded twice.
c. The first collision of the plane with an obstacle occurred at a distance of about 1100 meters from the runway threshold and about 40 meters left from the runway centerline. Taking into account the terrain (ravine) and the tree height, aircraft was 15 meters below the runway threshold level.
d. The third collision of the left wing, which led to the destruction of the aircraft structure, with a birch trunk diameter of 30-40 cm occurred at a distance of 260 meters from the point of the first contact 80 m to the left of the extended runway centerline.
e. Time elapsed from the beginning of the aircraft destruction to the complete destruction of the aircraft fuselage structures due to collision with the ground in inverted position was about 5-6 seconds. The final destruction of the aircraft occurred at 10 o'clock 41 minutes 06 seconds.
f. Medical studies have shown that at the time of the aircraft destruction in an inverted position the passengers were subjected to overloads of 100 g. Survival in this incident was not possible.