What happened
On 31 December 2009, a Fletcher FU24-950, registration PK-PNX, was conducting a ferry flight from Ujung Tanjung to Tangar airstrip. The flight, operated by PT. Sinar Mas Super Air, included a pilot and an aircraft maintenance engineer. After an overnight stop at Ketapang, the aircraft was cleared for departure from Rahadi Oesman Airport.
Shortly after takeoff at 01:25 UTC, the aircraft departed from the runway intersection and crashed only one minute later. The aircraft struck the roof of a local hospital and subsequently broke into several pieces in a nearby parking area, approximately 1.5 kilometers from the flight path centerline. The impact resulted in two fatalities, claiming the lives of both the pilot and the engineer.
The investigation
The investigation examined the wreckage, the engine components, and the fuel system. Investigators found that the propeller blades were in a fine pitch position with no signs of rotating impact, indicating the engine was not producing power at the moment of impact. The aircraft's nose landing gear had struck the hospital roof first, followed by the forward fuselage hitting vehicles in the parking lot.
Technical analysis of the airframe fuel pumps revealed surface corrosion on the pressure regulator spring, the plate, and the van pump. Additionally, the low-pressure filter showed evidence of water contamination, indicated by the presence of gel.
Findings
- The aircraft was airworthy and the pilot was fit for duty prior to departure.
- The engine was not under power when the aircraft struck the hospital roof.
- Corrosion within the booster pump provided evidence that the fuel supply had been contaminated.
- The fuel system's booster pump was subject to surface corrosion, likely a reaction to contaminated fuel.
Safety action
Following the accident, the operator issued a safety notice regarding the prevention of engine failure due to water contamination entering fuel tanks during overnight stops or following rain. The NTSC has recommended that the maintenance program for the airframe fuel pumps (part number CJ 10000–D) be transitioned from an "on-condition" basis to a fixed-interval "hard time" maintenance schedule.