PZL-Mielec AN-2

The cause of the accident was the collision of the airplane, which was excluded from the state register of civil aircraft of Ukraine, with the earth's surface, which led to the destruction of the aircraft and the death of the person piloting the plane ; the landing by an unprepared person at night on an unprepared and unequipped plot of land, which resulted in the person piloting the aircraft losing its spatial position and colliding with the ground.
The following contributing factors were identified:
- Failure to release the flaps into the landing position.
- Landing at high speed.
- Admission of a large left roll before landing.

The accident with the An-2 RA-71276 aircraft occurred as a result of a collision with a mountain at an altitude of 2,780 metres above sea level perpendicular to the direction of the ridge with its minimum height of 2,960 metres conditions of limited visibility and the closure of mountain tops by clouds.
The following contributing factors were identified:
- The crew took the decision to perform a flight over a mountainous area with predicted closure of the mountains by clouds and unfavorable wind conditions,
- The crew took the decision to return to the landing site through the mountain range along an unexplored and previously unused route,
- Operational fatigue of the crew due to the significant duration of working hours on the day of the accident (more than 12 hours),
- The airplane falling under the influence of descending air currents on the leeward side of a mountain slope.

The cause of the accident with the An-2 RA-40851 aircraft was the collision of the aircraft with a reinforced concrete support and power transmission lines in a controlled flight while performing the aerial application at an extremely low altitude.
The contributing factors most likely were:
- Field processing when the sun is less than 15° above the horizon and the sun's heading angle is less than 30°,
- Insufficient prudence of the PIC when performing a VFR flight for aerial application,
- Failure of the pilot to take into account the presence of artificial obstacles in the flight area,
- Lack of marking of power lines.

The aircraft stalled during initial climb because its total weight was above the MTOW and the CofG was well beyond the aft limit. The crew failed to prepare the flight according to procedure and, failed to proceed with a mass and balance calculation and the passengers and lugages were incorrectly placed in the cabin according to the CofG.

The accident was caused by the fact that the PIC did not maintain a safe flight altitude in mountainous terrain, which led to the aircraft getting into strong downdrafts while flying over the leeward side of the ridge, uncontrolled descent and collision with the top of the mountain.
The contributing factors of AP, most likely, were:
- insufficient analysis of meteorological conditions and the possibility of the formation of strong ascending and descending air currents in the mountains;
- Failure of the PIC to take safety measures when flying in the mountains and to act in case of falling into downward air currents when crossing a mountain ridge;
- the use of motor gasoline with an octane rating of less than 95, which led to a decrease in engine power;
- performing a mission on the An-2 aircraft without the procedure for restoring skills and admission to flights on this type after a significant break in flights (about 15 years).

The immediate cause of the accident was a forced landing caused by a loss of engine power on unsuitable terrain. The most likely cause of the loss of engine power is the use of a low quality A-95 motor gasoline.