What happened
On 14 November 2013, a Cessna C208B, registration PK-RSP, operated by PT Enggang Air Service, performed an unscheduled passenger flight from Sentani Airport to Nalca Airstrip in Papua. The flight, which carried one pilot and nine passengers, was conducted under Visual Flight Rules (VFR). This was the pilot's first experience flying the route between these two locations.
While weather conditions were calm and visibility was good, the aircraft encountered difficulties during the landing phase on runway 24. After touching down at approximately 78 knots, the aircraft rolled slightly right of the centerline. Approximately 20 meters before reaching the parking area, the right main wheel became trapped in the runway surface. The force of the impact caused the right wing to dip and the right wheel to become buried in the ground by roughly one meter. The aircraft sustained damage to the propeller blades, nose landing gear, engine cowling, and engine mounting, but there were no injuries to the occupants.
The investigation
The investigation focused on the condition of the Nalca Airstrip and the information available to the crew. Investigators noted that while the aircraft was airworthy and within weight limits, the runway surface—consisting of grass—had been affected by rainfall the previous day.
Technical analysis of the propeller ground clearance revealed that the blades would strike the surface if any wheel sank more than 22.9 cm into the ground. In this instance, the right wheel sank significantly deeper than that threshold. The investigation also reviewed the operator's Safety Management System (SMS) and Company Operation Manual (COM) regarding risk assessment and the responsibility of flight operations officers to provide updated aerodrome information.
Findings
- The pilot was operating on a route they had never previously flown.
- Heavy rainfall occurred in the area one day prior to the incident.
- The pilot was not provided with updated information regarding the changed condition of the runway surface.
- The right main wheel sank deep enough into the soft surface to cause the aircraft to stop abruptly and sustain structural damage.