What happened
On 19 January 2014, a Piper Chieftain PA 31-350, registration PK-IWT, was performing a positioning flight from Sentani Airport, Jayapura, to Juanda Airport, Surabaya, for scheduled maintenance. The flight, operated by PT. Intan Angkasa Air Service, included a planned refueling stop at Dumatubun Airport in Tual, Maluku. On board were the pilot, two company engineers, and one ground staff member.
During the approach to Langgur Airport, the aircraft encountered rainy and thunderstorm conditions. While descending through 2,500 feet, the pilot requested to use runway 27. Shortly after, communication between the aircraft and the Langgur Flight Information Service Officer (FISO) ceased. At approximately 03:40 UTC, local residents reported that the aircraft had crashed. The wreckage was located roughly 1.6 nautical miles northeast of the airport. The impact and subsequent fire resulted in four fatalities and the total destruction of the aircraft.
The investigation
Investigators examined the wreckage, engine components, and propellers to reconstruct the final moments of the flight. Analysis of the left wing's leading edge indicated a significant roll to the left prior to impact. While the right engine showed signs of high rotational energy at impact, the left propeller exhibited much less damage and minimal rotational energy.
Further examination of the aircraft's configuration revealed that the landing gear was down and the flaps were extended, confirming the aircraft was in a landing configuration. The investigation also noted that the aircraft was not equipped with flight recorders, which limited the ability to capture the specific radio communications and cockpit telemetry during the emergency.