Flight Chronology
The aircraft was conducting a ferry flight from its home base at Ujung Tanjung/Pekanbaru to Tangar airstrip in Central Kalimantan. The flight was authorized under approval number D09-038960 and security clearance AU05-033328. On board were one pilot and one aircraft maintenance engineer.
On 29 December 2009, the aircraft departed Ujung Tanjung, transited through Jambi, and stopped overnight at Pangkal Pinang Airport, Bangka, accumulating 3 hours of flight time. The next day, 30 December 2009, it continued from Pangkal Pinang to Rahadi Oesman Airport in Ketapang, West Kalimantan, flying 1 hour 40 minutes, and remained overnight.
On 31 December 2009, the aircraft planned to continue to Tangar Airstrip. Prior to departure from Ketapang, the aircraft was declared airworthy.
Accident Sequence
At 01:17 UTC (08:17 local time), the pilot requested engine start. At 01:24 UTC, taxi clearance was requested, and Air Traffic Control (ATC) cleared the aircraft via taxiway A. The pilot requested takeoff from runway 17 intersection, which was approved. ATC asked the pilot to report when ready; upon receiving that report, departure clearance was given.
The aircraft departed at 01:25 UTC. One minute later, at 01:26 UTC, it crashed, striking the roof of a hospital and breaking into pieces in a parking area approximately 1.5 kilometers to the left of the flight path centerline. The aircraft was substantially damaged. The pilot and engineer were both fatally injured.
Findings and Probable Cause
The investigation concluded that the aircraft engine was not producing power during impact with the hospital roof. A corroded fuel pump was found, indicating the presence of contaminated fuel. Other findings included:
- The aircraft was airworthy before departure.
- The pilot was fit for flight.
- The booster pump showed surface corrosion on its spring, plate, and vane pump, consistent with contaminated fuel.
- According to the Fletcher Flight Manual and Pilot Operating Handbook (Chapter 3.10, Fuel System Failure), the booster pump should have been operated before flight.
- Propeller blades were in fine pitch with no signs of rotating impact, confirming the engine was not powered when the aircraft struck the ground.
- No evidence of preexisting engine damage was found.
The probable cause, as determined by the official investigation, was that the engine was not delivering power during impact, attributed to a corroded fuel pump from contaminated fuel.