What happened
On 18 January 2022, a PAC 750XL, registered P2-BWE, was performing a single-pilot VFR charter flight from Kiunga Airport to Tekin Airstrip in the Sandaun Province of Papua New Guinea. The aircraft, operated by Niugary Aviation Services Limited, was carrying one pilot and seven passengers.
During the landing roll at Tekin Airstrip, the aircraft's left main landing gear assembly collapsed. The touchdown occurred approximately two meters short of the designated landing threshold on runway 18. As the aircraft touched down, the main landing tires struck an elevated edge of the runway, which was 15cm high. This impact caused the left gear to weaken and subsequently fail. Following the collapse, the left wing dropped to the ground, and the aircraft veered toward the eastern boundary of the airstrip, eventually impacting a drainage ditch adjacent to the runway. All eight occupants survived the event.
The investigation
The investigation examined the aircraft's maintenance history, the pilot's training, and the operational procedures of the operator. Investigators reviewed the aircraft's structural integrity, engine performance, and the condition of the landing gear components. The inquiry also assessed the suitability of the Tekin Airstrip and the adequacy of the operator's safety management and maintenance practices.
Findings
- The investigation determined that the left main landing gear assembly collapsed because the impact forces from hitting the elevated runway edge were transferred through the structure.
- The pilot had not completed required route and aerodrome checks as specified by the operator's procedures and civil aviation regulations.
- The operator had not fully implemented its hazard management process, specifically regarding hazard identification and reporting.
- The operator's pressure gauges, used for servicing the aircraft, were not calibrated.
- The aircraft's tire or oleo strut pressures may have been outside of specified tolerances due to the use of uncalibrated equipment, which likely reduced the damping effect during the impact.
- The airstrip's threshold marker was not clearly visible, and the positioning of runway cones did not meet regulatory standards.
Safety action
The AIC issued several recommendations to the operator, including:
- Developing a comprehensive aerodrome register/guide that includes specific data, safety procedures, and operational limitations.
- Enhancing the change management process to identify safety hazards associated with new business activities or aircraft introductions.
- Ensuring staff awareness and enforcement of hazard identification and risk management processes.
- Requiring all flight crew to complete mandatory route and aerodrome checks in compliance with standard operating procedures.