What happened
On 12 December 2008, a de Havilland Twin Otter DHC6-400, registration PK-BRS, was performing a scheduled flight from Ewer to Timika, Papua. During the takeoff roll on runway 24, the aircraft began to slide and veer toward the right. The pilot in command took control from the handling copilot to correct the deviation, but the aircraft subsequently swung sharply to the left across the centerline.
In an attempt to recover the aircraft, the pilot utilized nose-wheel steering, but the maneuver failed to keep the aircraft on the runway. The aircraft exited the steel matting surface and entered the adjacent wet, soft ground. The nose section of the aircraft struck the earth, causing the nose landing gear to sink and resulting in substantial damage to the forward fuselage, the nose-baggage compartment, and the nose-wheel taxi light. The aircraft came to a rest 3 and 60 meters from the runway end. All 21 occupants, including 18 passengers, escaped without injury.
The investigation
The investigation examined the aircraft's mechanical condition, the runway surface, and the crew's actions. Investigators found the aircraft was airworthy and properly loaded. While the investigation noted that several Marsden matting fixing pins were protruding above the steel plates—posing a potential hazard to tires—no tire damage was observed. The investigation also noted that the Ewer airstrip's high-frequency radio was unserviceable at the time of the incident.
Findings
- The crew did not utilize asymmetric power to counteract the directional deviation.
- The aircraft's rudder cable tension loss was a result of structural distortion during the impact rather than a mechanical failure.
- The pilot in command likely over-corrected the aircraft's movement using nose-wheel steering, leading to the loss of directional control.
Safety action
Following the inquiry, the NTSC issued several recommendations to the Directorate General of Civil Aviation, including:
- Ensuring remote airstrips have reliable communication methods with regional authorities.
- Requiring operators of Marsden matting runways to inspect for exposed locating pins.
- Ensuring that adequate traction can be maintained on steel matting surfaces during wet weather conditions.