Landing (descent or approach)

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.

It is believed that the loss of control on final approach was the consequence of the failure of both right engines n°3 and 4.

The pilot did not maintain airspeed while maneuvering, which resulted in an aerodynamic stall.

Findings:
- The licenses and qualifications held by the flight crew, flight and duty times, the documented technical status of the aircraft and the aircraft mass and balance had no influence on the sequence of events
- The flight crew planned the flight from BGKK to BGGH with the destination alternate BGSF
- The latest BGGH TAF before departure from BGKK indicated marginal weather conditions (strong winds, low visibility and low cloud base) for a successful approach and landing at BGGH
- The forecasted weather conditions at the expected approach time at BGGH were below preplanning minima (use of two destination alternate aerodromes)
- The actual weather conditions at BGGH and enroute weather briefings were equivalent to the forecasted weather conditions
- With reference to the operator’s aerodrome and procedure briefing and the latest reported wind conditions from Nuuk AFIS before landing, a landing was prohibited
- Strong winds and moderate to severe orographic turbulence from the surrounding mountainous terrain increased the flight crew load
- On approach, the flight crew had difficulties of maintaining stabilized approach parameters
- The flight crew most likely suffered from task saturation and information overload
- No flight crew call outs on divergence from the operator’s stabilized approach policy were made
- An optimum crew resource management was not present
- Important low altitude stabilized approach parameters like airspeed, bank angle and runway alignment were not sufficiently corrected
- The flight crew was solely focused on landing and task saturation mentally blocked a decision of going around
- A divergence from the operator’s stabilized approach policy caused an unstabilized approach and a hard landing leading to an excess load of the right MLG at touchdown
- The right MLG fuse pin sheared as a result of overload
Factors:
- A divergence from the operator’s stabilized approach policy caused an unstabilized approach and a hard landing leading to an excess load of the right MLG at touchdown
- The right MLG fuse pin sheared as a result of stress
Summary:
Adverse wind and turbulence conditions at BGGH led to flight crew task saturation on final approach and a breakdown of optimum cockpit resource management (CRM) resulting in a divergence from the operator’s stabilized approach policy.
The divergence from the operator’s stabilized approach policy caused an unstabilized approach and a hard landing leading to an excess load of the right MLG at touchdown. According to its design, the right MLG fuse pin sheared as a result of stress.

Comprehensive technical examination of the nose wheel steering on OY-NPB uncovered no single causal factor, but some indications of unsatisfactory maintenance. Irregularities that alone or in combination could have caused a temporary fault with the steering were present. The Accident Investigation Board believes that a temporary fault caused the nose wheel to unintentionally lock itself in a position towards the right. No other defects or irregularities that could explain why the aircraft veered off the runway were found. The AIBN reported that the same fault had occurred 6 days earlier as well, during that encounter the captain managed to disconnect nose wheel steering quickly enough to regain control. Maintenance could not replace the fault and the aircraft was released to service.

The ATSB found that the aircraft had not broken up in flight and that it impacted the water at a relatively low speed and a near wings-level attitude, consistent with it being under control at impact. It is likely that the pilot encountered rain and reduced visibility when manoeuvring to commence a visual approach. However, there was insufficient evidence available to determine why the aircraft impacted the water.
Several aspects of the flight increased risk. The pilot had less than 4 hours sleep during the night before the flight and the operator did not have any procedures or guidance in place to minimize the fatigue risk associated with early starts. In addition, the pilot, who was also the operator’s chief pilot, had either not met the recency requirements or did not have an endorsement to conduct the types of instrument approaches available at Horn Island and several other locations frequently used by the operator.

The pilot did not maintain control of the airplane while making a low-altitude turn during dark night conditions.