Airport (less than 10 km from airport)

The investigation concluded the probable cause of the accident was that the aircraft lost control on final approach to runway 33 as a result of flying with asymmetrical power.

The pilot's failure to lower the landing gear before landing. Contributing to the accident was the examiner's failure to check that the landing gear was extended.

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 investigation determined that the accident was caused by the following probable cause(s):
- Loss of in-flight control as a result of slowing below Minimum Control Speed and drag, generated by the failure of the right engine (No. 2).
- Failure of engine No. 2, due to lack of lubrication, possibly caused by oil leakage through an 11.5 mm fracture, found in one of the sides of cylinder No. 2 at the height of the intake valves.
- Inappropriate application by the crew of the emergency procedure for landing with an inoperative engine, by not declaring the emergency, not feathering the propeller of the inoperative engine and configuring the aircraft early for landing (with landing gear and flaps) without having a safe runway, making it difficult to control the aircraft and placing it in a condition of loss of lift and control.

Contributing Factors:
- Failure of the operator to emphasize in the crew training program the techniques and procedures to be followed in the event of engine failure, among others, the declaration of emergency to ATC, the flagging of the propeller of the inoperative engine, the care in the application of power to the good engine so as not to increase yaw and not to configure the aircraft until landing has been assured.
- Lack of emergency calls by the crew, which denotes deficiencies in the Operator's Safety Management System, and which prevented the early warning of the aerodrome support services and deprived the crew of possible assistance from other aircraft or from the same operator.

The accident with the Boeing 737-500 VQ-BPS aircraft occurred during the landing as a result of a collision of the aircraft with a snow parapet 1.1 m high at a distance of 32 m to the runway threshold (within the paved section of the runway), which resulted in damage to the main landing gear and their subsequent "folding" in the process of moving along the runway.
The accident was caused by a combination of the following factors:
- the presence of contradictions in the Federal Aviation Rules for flights in the airspace of the Russian Federation, the airline's radio control system and the aircraft operational documentation regarding the need and procedure for introducing temperature corrections to the readings of barometric altimeters at low ambient temperatures;
- Failure by the operator of the Usinsk aerodrome to comply with the FAP-262 requirements for the maintenance of the aerodrome, which resulted in the presence of snow parapets on the paved section of the landing strip;
- the operator of the Usinsk aerodrome did not eliminate the shortcomings in the winter maintenance of the aerodrome, noted based on the results of the inspection by the Rosaviatsia commission on January 22, 2020;
- lack of risk assessment in the airline associated with the execution of approaches in the baro-VNAV mode in the presence of factors that impede such approaches (low ambient temperatures, snow-covered underlying surface, drifting snow (snowstorm), significant changes in the relief in front of the runway end, lack of PAPI-type lights), as well as appropriate recommendations to the crews on the specifics of such approaches, including after the transition to visual flight, and crew training;
- insufficient assessment by the crew during the preparation of the existing threats (hazard factors) and making an insufficiently substantiated decision to perform an RNAV (GNSS) approach (under the control of the autopilot in LNAV/VNAV mode) without introducing a correction for low outside air temperature in altitude overflying waypoints, which led to a flight below the established glide path;
- performing a flight along the "extended glide path" after turning off the autopilot and switching to manual piloting without attempting to enter the set glide path;
- the PIC may have had a visual illusion of a "high glide path" due to a snow-covered underlying surface, a snowstorm and the presence of a ravine directly in front of the runway end in the absence of PAPI type lights, which led to an incorrect assessment of the aircraft's flight altitude after switching to manual piloting, lack of reaction to timely and correct warnings of the co-pilot and exit to the runway end at a height significantly less than the established one.

A total loss of engine power in both engines due to fuel exhaustion, which resulted in a landing short of the runway.

The Aircraft Accident Investigation Board determines that the probable causes of this accident were the pilots’ failures below, resulting in a runway overrun:
- Poor decision-making for acceptance of the risk of high-speed landing;
- Un-stabilized approach against the normal flight profile;
- Poor CRM in the cockpit; and
- Poor judgment and not accomplishing go-around while performing an unstabilized approach.

Contributing Factors:
- Loading of 5 tons of extra fuel, which increased the landing distance required.
- Decision to make a landing on RWY 13 with tailwind.
- Inability of the copilot (PM) to take control of the aircraft and proper action to execute goaround.

A total loss of engine power due to a combination of mechanical engine anomalies. Contributing to the accident was inadequate maintenance that failed to identify the engine anomalies.