Russia

Loss of engine power following a bird strike. It was determined that the aircraft collided with a bird during initial climb and that the bird came to rest in the carburetor air intake.

Engine failure due to poor maintenance. Deficiencies were reported during investigations regarding the operator's maintenance procedures. The documentation related to aircraft maintenance was incomplete. Also, several mechanics and engineers working on the AN-2 fleet were not qualified and authorised to do so.

The crew's decision to continue the approach after the decision height without any visual contact with the ground until the aircraft collided with trees and impacted terrain. The crew failed to follow the published procedures and to initiate a go-around manoeuvre.

In-flight fire for unknown reasons.

Failure of the protection system of the elevator trim, causing a spontaneous deflection of the elevator. This caused the aircraft to enter an uncontrolled descent and the crew was unable to regain control. Violations about aircraft maintenance, flight organization and operational aspects were identified within the operator. Excessive G loads during the descent caused the aircraft to partially disintegrate before final impact.

The following contributing factors were identified:
- A possible unpremeditated entry into conditions with severe icing and late decision making by the captain to manoeuvre the aircraft away from the icing area,¨
- A loss of engine power and a subsequent loss of speed due to icing of the carburetor,
- The failure of the captain to remove ice from the propeller blades by changing their pitch mode.

The following contributing factors were identified:
- A series of negligences was noted in the operations of the company and the maintenance of the airplane,
- The flight was not properly prepared and the total weight of the aircraft was well above the MTOW,
- Due to the combination of the following factors, the pilots did not take the corrective actions to maintain a good climb path:
- Lack of seriousness and lack of documentation control during cargo loading at Chkalovsky Airport,
- Lack of rigor and non-compliance with standard operating procedures regarding the pre-takeoff check of the cargo, which led the ground personnel to load cargo with a total weight in excess of 13,6 to 14 tons,
- At takeoff, the total weight of the aircraft was estimated to be 204 tons while it was certified for a maximum weight of 191.9 tons taking into account all factors at the time of the accident,
- All crew members were unable to identify in due time the successive errors made by the captain (pilot-in-command), among others the stabilizers that were prematurely positioned in an angle of -3.9 ° while the trailing edge flaps were retracted, causing the lift to be insufficient,
- The coordination within the flight crew was ineffective and the copilot and the navigator did not pay sufficient attention to the altitude of the aircraft through flight conditions in reduced visibility,
- Lack of visibility caused by foggy conditions which did not allow the flight crew to distinguish in time the obstacles located past the runway end,
- As a result of this accident, the operator certificate was revoked.

The accident was the consequence of a crew error in the piloting technique when flying in difficult terrain conditions, which manifested itself in a loss of speed and flight altitude, which led to an unintentional landing of the aircraft and its collision with ground obstacles. The error in the piloting technique became possible due to the unstable piloting skills of the pilot-in-command and the failure of the instructor to fulfill his duties. It was reported that the pilot-in-command did not fly for about five years.