Background
The first prototype of the AN-70 aircraft departed Kiev-Gostomel Airport for a test flight aimed at evaluating stability and controllability as part of the certification program. The aircraft carried seven crew members. An Antonov AN-72, registered UR-72966 and operated by the Antonov Design Bureau, also departed from the same airport to participate in the same control flight.
Collision
While cruising at an altitude of 3,200 metres, the crew of the AN-70 maneuvered to approach the AN-72. They misjudged the distance between the two aircraft, resulting in a collision. The tail of the AN-70 struck the fuselage of the AN-72.
Aftermath
The crew of the AN-72 was able to return to Kiev-Gostomel Airport and complete a safe landing. All crew members aboard the AN-72 were uninjured, but the aircraft sustained severe structural damage and was deemed beyond repair. The AN-70 lost its left stabiliser and part of its tail upon impact. Subsequently, the aircraft entered a dive and crashed in a wooded area in Veliky Lis, approximately 45 km northwest of Kiev-Gostomel Airport. All seven occupants of the AN-70 were killed.
Probable Cause
The official investigation determined that the collision was the consequence of errors by the AN-70 crew, who misjudged the distance between both aircraft and initiated a hazardous maneuver without knowing the exact position of the second aircraft. Contributing factors included the collision occurring while both aircraft were facing the sun, failure of both crews to use appropriate radio communications, loss of situational awareness, loss of the left horizontal stabiliser and part of the tail, failure of all four hydraulic systems, and loss of controllability.