Landing (descent or approach)

Failure of the brakes is suspected.

The most likely cause of the accident would have been the loss of control of the aircraft when performing the flare, caused by a loss of lift (stall), because the CofG was beyond the rear limit.
The following contributing factors were identified:
- The aircraft was unstable on its longitudinal axis because the CofG was too far aft,
- The cargo was not properly secured in the cabin.

The pilot did not maintain minimum controllable airspeed while on final approach with a partial loss of power in the right engine, which resulted in a loss of control. Contributing to the accident was the partial loss of engine power in the right engine due to the improperly installed o-rings in the engine’s throttle and control assembly.

No investigation was carried out by the NTSB.

The pilot's inadequate compensation for the crosswind while landing, which resulted in a loss of directional control.

Weather in Kinshasa was bad at the time of the accident, ATC failed to inform the crew about the degradation of the weather conditions and the runway in use was not closed to traffic while the visibility was below the minima. Despite this situation, the crew took the decision to continue the approach procedure while the aircraft was unstable and the approach speed was too high (180 knots). It is reported that the following factors contributed to the accident:
- the crew ignored the published approach procedures,
- improper crew resources management during the execution of the flight,
- during the go around process, the crew encountered adverse weather conditions with vertical wind gusts, downdrafts and a 'magenta' effect. This caused the aircraft to adopt nose down attitude while it was in the final stage of the flight, preventing the pilot to take over the control,
- the pilot training program was inadequate and did not include a proportionate number of flight in the simulator,
- the authority for civil aviation of Georgia has probably approved a small training program for upgrading the captain to his position,
- lack of oversight of the operator by the Georgian Civil Aviation Authority.
In conclusion, investigators believe that the most probable cause of the accident is the fact that the plane encountered a very dangerous meteorological phenomena similar to a microburst, to a very low level during the overshoot process. The dangerous vertical downdraft and gust caused a sudden and remarkable change in the attitude of the aircraft and a substantial loss of altitude. Flying at very low altitude, recovery of such disturbance was not possible.

Conclusions
Findings as to Causes and Contributing Factors:
1. The right engine lost power when the intermediate spur gear on the torque sensor shaft failed. This resulted in loss of drive to the high-pressure engine-driven pump, fuel starvation, and immediate engine stoppage.
2. The ability of the left-hand No. 2 ejector pump to deliver fuel to the collector tank was compromised by foreign object debris (FOD) in the ejector pump nozzle.
3. When the fuel level in the left collector tank decreased, the left fuel level warning light likely illuminated but was not noticed by the crew.
4. The pilots did not execute the fuel level warning checklist because they did not perceive the illumination of the fuel level left tank warning light. Consequently, the fuel crossfeed valve remained closed and fuel from only the left wing was being supplied to the left engine.
5. The left engine flamed out as a result of depletion of the collector tank and fuel starvation, and the crew had to make a forced landing resulting in an impact with a concrete noise abatement wall.
Findings as to Risk:
1. Depending on the combination of fuel level and bank angle in single-engine uncoordinated flight, the ejector pump system may not have the delivery capacity, when the No. 1 ejector inlet is exposed, to prevent eventual depletion of the collector tank when the engine is operated at full power. Depletion of the collector tank will result in engine power loss.
2. The master caution annunciator does not flash; this leads to a risk that the the crew may not notice the illumination of an annunciator panel segment, in turn increasing the risk of them not taking action to correct the condition which activated the master caution.
3. When cockpit voice and flight data recordings are not available to an investigation, this may preclude the identification and communication of safety deficiencies to advance transportation safety.
4. Because the inlets of the ejector pumps are unscreened, there is a risk that FOD in the fuel tank may become lodged in an ejector nozzle and result in a decrease in the fuel delivery rate to the collector tank.
Other Findings:
1. The crew’s decision not to recover or jettison the birds immediately resulted in operation for an extended period with minimal climb performance.
2. The composition and origin of the FOD, as well as how or when it had been introduced into the fuel tank, could not be determined.
3. The SkyTrac system provided timely position information that would have assisted search and rescue personnel if position data had been required.
4. Saskatoon police, firefighters, and paramedics responded rapidly to the accident and provided effective assistance to the survivors.

The pilot's demonstration of poor judgment by attempting a high‐speed pass several feet above the runway and his subsequent failure to maintain clearance from the runway.

The pilot’s continuation of the approach with excessive airspeed, which resulted in a hard landing and a loss of directional control.