What happened
On the evening of 27 February 2020, a Royal Malaysia Police Leonardo AW139, registration 9M-PMC, was performing a repositioning flight from Tawau Airport to the 14th Battalion General Operations Force (GOF) camp. The flight was the final sortie of the day, intended to move the aircraft to the camp for security reasons ahead of scheduled tasks the following day.
As the crew approached a football field designated as the landing site, they initiated a northern approach at night. While at approximately 300 feet on short finals, the pilot experienced a sudden jerk in the controls, followed by a total loss of directional control. The aircraft began yawing uncontrollably to the right. The pilot issued a brace command before the helicopter struck a coconut tree and came to rest on its side near the camp's K9 section.
All six crew members on board survived the impact. While five members sustained only minor injuries, one trainee observer suffered a serious back injury that required hospitalization. Ground personnel from the GOF camp assisted in evacuating the crew from the wreckage.
The investigation
The AAIB investigation focused on the aircraft's performance capabilities and the environmental conditions during the approach. Investigators analyzed the aircraft's All-Up Weight (AUW) and compared it against the limitations for the specific landing site.
Data from the flight recorders revealed that the aircraft's weight exceeded the safety threshold for the intended confined area landing. Furthermore, the investigation examined meteorological data and the mechanical state of the aircraft's systems during the critical phase of flight.
Findings
- The aircraft was operating at an excessive All-Up Weight; the calculated weight was 6,598.39kg, which exceeded the 6,400kg limit required for a safe landing at the 14 Bn GOF site.
- The crew had not burned off enough fuel to reach the required safety weight, leaving the aircraft roughly 11 minutes of flight time short of the necessary weight reduction.
- A slight tailwind was present during the approach, which further compromised the aircraft's performance envelope during the confined area operation.
- The torque limiter was engaged during the accident, contributing to the loss of control.