Russia

The aircraft collided with the wires of an overhead power line, which had no night markings, with subsequent collision with trees and ground.
The following contributing factors were identified:
- Inadequate experience of the pilot in night flying conditions,
- Violation of the AN-2 flight manual, which prescribes instruments night flights,
- Decision to fly at night to a landing site without adequate light equipment,
- Flying at an altitude lower than the prescribed altitude of unlit obstacles, of which the pilot was aware,
- Decision of the pilot to perform the flight in a reduced crew configuration (without a copilot).

It is believed that the double engine failure is the consequence of a fuel exhaustion.

Controlled flight into terrain after the crew continued to fly under VFR mode in IMC conditions.
The following contributing factors were identified:
- Unreasonable flight decision taken by the flight crew,
- The forecasted weather on the declared route did not ensure compliance with ATC,
- Failure of the pilot-in-command to take timely measures to return to the departure airfield or to take other actions to change the flight plan.

The accident probably occurred as a result of its entry into subcritical angles of attack and stall mode after a takeoff with the maximum permissible weight and reduced power of the propulsion system. Most likely, the reduced power was due to the installation of a magneto switch prior to the PM-1 magneto switch to position “1” instead of position “1+2” as required in the flight manual.
The following contributing factors were identified:
- Long flight interruptions of both crew members before the emergency flight,
- Deficiencies in the training and interaction of crew members,
- Insufficient level of flight training, which resulted in a loss of control of the flight speed.

The cause of the accident was that the airplane was flying over the radio beacons of runway 05R of Khabarovsk-Novy) Airport in instrumental meteorological conditions (IMC) at an altitude of 600 metres QFE, which was significantly lower than the established minimum safe altitude of 1,200 metres QFE in the sector where the accident occurred, which led to a collision with the mountain slope and resulted in a controlled flight into terrain (CFIT).

The following contributing factors were identified:
- Lack of current regulatory documents governing the conduct of flight inspections of ground-based flight support equipment, avionics, and civil aviation lighting equipment systems, including for airfields whose topographical features do not allow inspections to be conducted according to standard procedure;
- Unreasonable establishment of a continuous exclusion zone from 0 m to 6000 m by altitude within a radius of 99900 m from KTA for the function of signaling aircraft descent below the minimum safe altitude (MSAW), which excluded issuing a corresponding warning to a DPC dispatcher;
- Absence of the ATC Dispatcher's Work Procedure at the ATC and other documents of the ATC of EU ATS (Khabarovsk):
- procedure for ATC specialists when flying over the aerodrome's RMS;
- procedure for practical training of ATC specialist performing direct ATC under the control of ATC instructor, including their interaction and responsibility for ensuring flight safety.
- Making a decision to combine two sections of trainee navigator training without the necessary risk analysis and risk mitigation measures;
- Insufficient preliminary preparation of the crew for the overflight, including failure to take into account the terrain features (presence of zones with considerable elevation) and geographical features (proximity to the state border) of the airfield, as well as the presence in the crew of a trainee navigator not admitted to independent flights and to this particular type of work;
- Insufficient cooperation between the crew and ATC specialists when preparing and performing the overflight, including coordination by the crew and ATC specialists during the flight of the maneuver with violation of the established minimum safe altitude when performing a flight under instrumental weather conditions;
- Interference of the instructor navigator in the flight procedure (route change) without assessing the relevant risks in the absence of the pilot's control;
- Failure of the trainee navigator to comply with the operating procedures in terms of comprehensive use of aircraft equipment for precise piloting, maintenance of safe altitudes and timely informing the crew about turns, as well as lack of proper control over his actions on the part of the instructor navigator;
- Lack of control over the aircraft flight by the trainee controller and instructor controller at their minimum workload (controlling only the aircraft which had suffered a crash).
- The Operator's Flight Operations Manual lacked standard operating procedures for crew operation regarding the EGPWS Mark VIII system installed on board the aircraft. There were no warnings of this system during the flight. Probably, the system was not activated by the crew prior to the flight, maybe to avoid frequent activation during the flight. Due to the complete destruction of the system as a result of the crash, it was impossible to determine the cause of its failure. A proper use of this system may have prevent the accident.

The accident was the consequence of the crew's non-compliance with the rules for visual flights at night, which was expressed in making an approach to land with visibility below the established minimum values, leading to a collision with natural obstacles and resulting in a controlled flight into terrain (CFIT).
The following contributing factors were identified:
- The discrepancy between the coordinates of the runway thresholds at Kazachinskoe in the GPS receivers of the aircraft commander and the co-pilot and their actual values, which led to an incorrect calculation for landing ;
- The failure of the aircraft commander to make a timely decision to divert to an alternate airport despite having information about the meteorological conditions not meeting the established minimum values. The individual psychological characteristics of the aircraft commander allowed him to make leadership decisions, but in the case of their erroneousness, he did not possess the ability to correct them and was inclined to unjustifiably risky, dangerous decisions ;
- The crew's use of the autopilot in the final stage of flight, which did not comply with the Flight Operations Manual. The autopilot modes selected significantly reduced the crew's situational awareness. In fact, the descent was carried out significantly to the right of the extended runway centerline over an area that lacked light landmarks ;
- The lack of proper interaction within the crew and insufficient monitoring of flight parameters.