What happened
On 30 January 2008, a de Havilland DHC-6-300 Twin Otter, registered PK-BRP, was performing a charter flight from Nabire to Sugapa, via Enarotali, in Papua, Indonesia. The aircraft, operated by PT. Aviastar Mandiri, was carrying 15 passengers, two pilots, and one engineer.
During the landing roll on runway 27 at Sugapa Aerodrome, the aircraft veered sharply to the left. The pilot in command was unable to maintain directional control, causing the aircraft to exit the paved surface. During the excursion, the aircraft struck a bystander standing near the runway edge, resulting in one fatality. As the aircraft moved off the runway, the right main wheel sank into soft ground, triggering an abrupt 270-degree swing to the right. This intense force tore the nose landing gear from the airframe, and the aircraft eventually came to a stop after impacting an embankment. While the aircraft sustained substantial damage, the 18 occupants were able to evacuate without injury.
The investigation
Investigators examined the wreckage and analyzed flight data and maintenance records. Evidence from the runway, including tire rubber marks and side-load scuffing, indicated a heavy landing where the nose wheel struck the surface with significant force before the left main gear. The investigation confirmed that the nose landing gear fork had cracked and deformed due to this high impact force.
While the pilot in command noted a historical tendency for this specific aircraft to veer left during ground rolls, investigators found no documented defects in the maintenance logs to support this. No mechanical malfunctions or pre-existing defects were identified that could have contributed to the loss of control.
Findings
- The primary cause of the accident was the nose landing gear fork cracking and deforming due to a high-impact force during touchdown.
- The pilot in command was unable to maintain directional control during the landing roll.
- The aircraft was within weight and balance limits and was airworthy at the time of departure.
- There was no documented evidence in the aircraft maintenance logs regarding the reported tendency to veer left during ground operations.
Safety action
Following the investigation, the NTSC issued recommendations to both the operator, PT. Aviastar Mandiri, and the Directorate General of Civil Aviation. The committee emphasized the necessity of ensuring flight crews properly document all aircraft and system defects in the official maintenance logs to prevent undocumented handling characteristics from persisting.