What happened
On 31 May 2023, a PAC 750 XL aircraft, registration PK-TET, was conducting a non-scheduled cargo flight from Timika to the Duma Airstrip in Dumadama, Indonesia. The aircraft was transporting 870 kg of building materials. While the flight began under favorable weather conditions, the approach to the remote airstrip presented unique challenges. Due to intense sunlight creating a blind spot in the valley, the pilot bypassed the standard low-altitude flyover used to alert local villagers of the approaching aircraft.
As the pilot prepared to land on runway 08, they noted a muddy patch at the beginning of the strip and intentionally delayed the touchdown point. During the landing roll, the aircraft struck a boar crossing the runway. The impact caused the aircraft to veer off the paved surface, leading to the collapse and detachment of the left main landing gear. The aircraft eventually came to a stop with its nose wheel lodged in a drainage ditch. The pilot, the sole occupant, escaped without injury, though the aircraft suffered significant structural damage to its wings and stabilizers.
The investigation
The KNKT investigation focused on the sequence of events and the management of the airstrip. Investigators found that the pilot's decision to extend the touchdown required a higher pitch attitude, which significantly restricted the view of the runway surface immediately ahead. While the pilot had observed the runway to be clear during the downwind leg, the animal entered the path of the aircraft during the final moments of the landing.
Furthermore, the investigation examined the maintenance of the airstrip's perimeter. Although the facility is managed by local villagers under the supervision of the operator, the existing fencing was found to be in disrepair, featuring gaps large enough for wildlife to penetrate the runway area. The inquiry also noted that while a previous risk assessment had identified runway incursion as a hazard, there was no formal documentation of animal-related hazards reported to the company, which prevented the implementation of necessary mitigation measures.
Findings
- The primary cause of the excursion was the impact with a boar that entered the runway area through gaps in the perimeter fencing.
- The pilot's decision to delay the touchdown to avoid mud resulted in a pitch attitude that obscured the view of the runway surface.
- The airstrip's fencing was in poor condition, failing to prevent animals from accessing the landing area.
- A lack of formal hazard reporting regarding wildlife meant that previously identified mitigation strategies for runway incursion were never effectively realized.