What happened
On 17 April 2009, a Pilatus PC-6/B2-H4 Turbo Porter, registered PK-LTJ, was performing a visual flight rules (VFR) charter mission from Ilaga to Mulia in the Puncak Jaya District of Papua. The aircraft, operated by PT. Mimika Air, was carrying one pilot, one observer, and nine passengers, including an infant. The flight was also transporting election boxes for the National Government.
While flying the direct track between the two locations, the aircraft encountered cloud cover over the mountain range. The wreckage was discovered the following day on the slopes of Mt. G/ergaji at an elevation of approximately 12,000 feet. The impact occurred in an inverted attitude, and the aircraft was destroyed by the force of the crash and a subsequent fire. There were 11 fatalities.
The investigation
Investigators from the NTSC examined the wreckage and flight history to determine the cause of the accident. The investigation focused on the pilot's navigation and the environmental conditions at the time of the flight. Evidence from the wreckage suggested the aircraft was in uncontrolled flight at the moment of impact.
Key areas of inquiry included the pilot's route familiarity and the validity of his flight credentials. While the pilot held a valid Myanmar-issued Commercial Pilot License, the investigation noted that the Indonesian validation certificate was subject to the expiration of the original foreign license. Furthermore, the investigation looked into whether the pilot had completed the required 150 hours of route training mandated by the operator's certificate.
Findings
- The aircraft was flying on a direct track that passed over high terrain, which is not the standard route for this aircraft type due to the altitude of the peaks.
- The pilot likely entered cloud cover while operating under VFR, leading to spatial disorientation.
- The impact signature was consistent with the aircraft being in an inverted, uncontrolled state.
- There was evidence that the pilot may have been relying on GPS guidance rather than visual terrain references.
- The pilot may not have completed the necessary route and aerodrome familiarization required for operating in the complex, mountainous terrain of Papua.