An-2 accident at Sartan

Investigation

To investigate the incident, the Yakut Civil Aviation Directorate formed a commission of 5 people:

P. I. Yegorov — pilot-inspector, chairman of the commission;

I. G. Litovchenko — commander of the 274th Flight Detachment;

A. G. Kordova — senior navigator of the Batagay Joint Aviation Detachment;

M. S. Vasilyeva — deputy head of Batagay Airport for traffic;

A. V. Kochetkova — flight safety physician of the Yakut Civil Aviation Directorate.

When the central console was inspected, it was found that rod Sh6500-221-2 had become disconnected from the rocker of the normal throttle control lever. According to the aircraft's maintenance history, on 28 August 1985, 4 days before the incident, work was performed on this aircraft to adjust the engine idle, during which aircraft technician A. I. Blagodarny, having connected the rod to the rocker with a bolted joint, did not secure the nut with a cotter pin. It is worth noting that this connection is not involved in the idle adjustment. As a result, over the following several days the nut spontaneously unscrewed, until on the fateful flight the unsecured bolt fell out of the joint, thereby disabling the engine control system.

Cause

The cause of the accident was named as a failure in the engine control system caused by violations in the organisation of the technical operation of the aircraft (negligence and/or inattention of the aircraft technician).