Background
A local training flight was being conducted at Vitebsk. The aircraft was crewed by seven personnel.
Accident Description
On approach to the airport, a technical problem occurred involving the left flap. The flap retracted without command. Subsequently, the aircraft banked to the left and then dove into the ground, crashing approximately 12 kilometers from the airport. All seven crew members on board were killed.
Probable Cause
Official findings determined that a cog-wheel on the left flap broke during approach, causing an uncommanded retraction of the flap. Due to the resulting asymmetric flaps deployment, control of the aircraft was lost.