What happened
On August 2, 2009, a de Havill and DHC-6 Twin Otter, registered PK-NVC, was operating a scheduled flight from Sentani Airport to Oksibil Airport in Papua, Indonesia. The flight, operated by PT. Merpati Nusantara Airlines, was planned under visual flight rules (VFR) and carried 15 people, including two pilots, an engineer, 10 adults, and two infants.
During the flight, the crew communicated with an Indonesian Air Force aircraft regarding local weather conditions. However, the aircraft failed to arrive at its destination. A search operation began when the aircraft's fuel reserves were expected to be exhausted. On August 4, 2009, investigators located the wreckage at an elevation of approximately 9,300 feet, roughly 6 nautical miles from Oksibil. The impact was severe, and all 15 occupants were killed.
The investigation
Investigators examined the wreckage, flight recorder data, and meteorological reports to determine the cause of the accident. The investigation confirmed that the aircraft was airworthy and properly loaded at the time of departure. There was no evidence of mechanical failure or engine malfunction contributing to the crash.
Analysis of the Cockpit Voice Recorder (CVR) revealed that while the crew initially discussed weather and route adjustments, the copilot became increasingly concerned about visibility and haze shortly before the impact. The investigation also noted that the aircraft's Emergency Locator Transmitter (ELT) was not functional because it had missed its required service interval. Furthermore, the meteorological office had not provided weather updates for the specific area between Jayapura and Oksibil during the flight period.
Findings
- The aircraft was flying in a manner inconsistent with visual flight rules (VFR) while operating below the lowest safe altitude.
- The flight crew maneuvered the aircraft into cloud cover near a mountain gap northwest of Oksibil.
- The accident was consistent with controlled flight into terrain.
- The aircraft's ELT was unserviceable due to a lapse in the maintenance inspection schedule.
- There was a lack of available aviation weather information for the flight route from the local meteorological office.