Antonov AN-24

The accident occurred during landing with one engine inoperative as a result of a longitudinal-lateral rollout beyond the runway and subsequent collision with a building outside the aerodrome, resulting in damage to the aircraft structure and a fire. The landing was performed on a runway with an available landing distance of 1,503 metres that was significantly less than the distance required of 2,160 metres for the actual conditions.
Most likely, the accident was the result of the combination of the following factors:
- The decision by the pilot-in-command (pilot flying) to land without calculating the required landing distance;
- The incorrect choice by the pilot-in-command of the type and trajectory of the approach, which made it impossible to reduce the flight speed in time. Instead of visual maneuvering ('circle-to-land' maneuver) provided for in the approach pattern and agreed upon by the crew with the air traffic controller, the crew performed a visual approach;
- The absence in the airline's flight manual and the aircraft's flight manual of procedures for performing a visual approach maneuver ('circle-to-land' maneuver);
- Failure of the crew to take measures to go around for a second approach despite a significant discrepancy between the actual flight parameters and the criteria for a stabilized approach specified in the airline's flight procedures;
- Lack of crew coordination and cross-checking;
- Failure to follow a number of standard operating procedures in terms of informing the PIC (pilot in command) by other crew members about significant deviations of actual flight parameters from the published values;
- Insufficient crew resource management;
- Landing at a significant high speed (275 km/h instead of the recommended 220 km/h), which led the aircraft to land 530 metres pas the runway threshold;
- Incorrect use of the main landing gear wheel braking system by the crew, resulting in premature compression of the brake pedals (in the air), which, upon repeated contact, led to landing on the braked wheels of the right main landing gear with destruction of the tires and, subsequently, to the aircraft rolling sideways;
- Increased psychological and emotional stress on the part of the captain, compounded by his particular mental characteristics, contributed to the adoption of unreasonable decisions in the situation that had arisen.
- The left engine failed in flight due to abnormal operation of the fuel control system, probably the ADT-24. Due to the high degree of destruction of the system due to fire, it was not possible to definitively determine which unit failed and the cause of the failure. The abnormal adjustments of the left engine and deviations in the operation of its fuel control system manifested themselves long before the day of the accident and could have been detected by both flight and engineering personnel.

It was planned that an instructor should perform the flight with the crew but he did not show up, so the captain decided to do the flight without him. On final approach to Donetsk, the visibility was limited and the captain was authorized to descent until 1,000 feet on approach where he should establish a visual contact with runway 08 or the approach lights. At this decision height, he continued the approach without any calls to the rest of the crew despite he did not establish any visual contact with the runway. During the last segment, the aircraft banked right due to a too low approach speed of 103 knots, stalled and crashed. The crew failed to monitor the approach speed, and the captain decided to continue the approach despite the visibility was below minimums. At the decision height, he should abandon the approach for a go-around procedure.

The probable causes of the accident were the failure of the crew to go around and the descent well below decision height without visual reference to landmarks when the aircraft approached the airfield in weather conditions below the captain's, aircraft's and airfield's minima and in dangerous/adverse weather phenomena like thunderstorm, heavy rain and severe turbulence as well as the lack of appropriate response and required actions following terrain awareness warning system alerts resulted in a controlled flight into terrain, collision with obstacles and the destruction of the aircraft.
Contributing factors:
- the crew underestimated the weather conditions at the destination airport thus taking an erroneous decision to attempt an approach in thunderstorm and heavy rain showers,
- unsatisfactory meteorological support of the flight, the dispatcher and later air traffic control provided information about visibility, cloud and wind data that did not correspond to actual conditions that were significantly worse than minimums required,
- clearance for the approach by air traffic control despite the presence of dangerous weather phenomena (thunderstorm, heavy rain) at the aerodrome, which did not correspond to the standard operating procedures at Blagoveshchensk,
- inadequate staffing with a first officer who was performing his first flight after a prolonged leave without proper preparation and training,
- unsatisfactory crew interaction and the failure to adhere to standard operating procedures, especially the call outs of approaching decision height, the absence of a decision by the commander to continue the landing or go-around and the lack of action to recommend/initiate a go around by the first officer.

The Interstate Aviation Committee (MAK) released their final report in Russian concluding the probable causes of the accident were:
The catastrophe of the AN-24 RA-47302 occurred when ditching became necessary due to a fire in the left hand engine's nacelle. The destruction of the aircraft and loss of life was caused by collision with underwater obstacles that the crew could not anticipate or avoid. The fire in the left hand engine nacelle was caused by the fracture of a centrifugal breather releasing an air-fuel emulsion into the engine compartment as well as a delayed reaction to shut the engine down by the crew following an magnetic chip detector indication together with indications of oil pressure fluctuations, a burning smell and a low oil pressure indication. A delay in indicating engine vibrations to the crew as result of degradation of the engine vibration sensoring equipment, most likely caused by changes of the rotor speed of the engine as result of the aft bearing failure of the compressor rotor and/or misalignment of the sensor, which probably influenced the decision of the crew to shut the engine down with a delay. Cause of the fracture of the centrifugal breather was the destruction of the impeller due to prolonged exposure to hot air-fuel emulsion due to the failure of the aft compressor rotor support bearing. It was not possible to determine the cause of the destruction of the aft compressor rotor support bearing due to significant secondary damage. Most likely the destruction was caused by misalignment such as:
- Incorrect assembly of support parts mating with the compressor rotor during on-condition engine repairs,
- Or deviations from required geometry of support parts mating with the compressor rotor.
Contributing factors were:
- Psychological unpreparedness of the captain to shut the engine down due to lack of experience with the aircraft on one engine inoperative
- Late detection of the fire and as a consequence late attempts to extinguish the fire, it was however not possible to establish why the fire was detected late due to lack of objective information about the performance of the fire alarm systems.

Sudan's Central Directorate of Air Accident Investigation concluded the probable causes as follow:
The accident cause is a complex set of reasons. The aircraft impacted the ground on three wheels at high forward speed shearing off both engines and propellers and damaging the left main landing gear which put the aircraft in an uncontrollable condition.
Contributory factors were:
- Absence of crew coordination,
- Absence of cabin procedure and check-lists for different phases of flight,
- Unsatisfactory Periodic and Annual job check being reflected on the inoperative Cockpit Voice and Flight Data Recorders,
- Bad planning of the flight and long period taken to clear the recorded defects before departure is considered to be a contributory factor to this accident.