Accident
On December 9, 2024, at approximately 1055 local time, a Storch CL ultralight aircraft (registration JJ2258) operated by the Taiwan Flying Players Association departed from Runway 26 at the Jiehao activity site in Gaoshu Township, Pingtung County. The aircraft carried a 52-year-old male pilot and one passenger. After climbing to about 100 feet, the engine lost power. Approximately 7 seconds later, the aircraft crashed about 340 meters west of the Runway 08 threshold. Both occupants sustained injuries and were transported to a hospital. The aircraft sustained substantial damage.
Aircraft and Engine Details
The aircraft was a fixed-wing ultralight manufactured by Fly Synthesis (Italy), model Storch CL. It featured a high-wing design, single engine, side-by-side seating, and a fixed tricycle landing gear. The wingspan was 10.140 m, length 6.250 m, and height 2.450 m. The maximum takeoff weight was 450 kg, empty weight 280 kg. The engine was a Jabiru 2200A Gen4, an air-cooled, four-cylinder horizontally opposed engine producing 60 kW (80 hp). The aircraft used a two-blade carbon fiber propeller. The fuel system consisted of two 40-liter tanks (total 80 liters). The cockpit included analog instruments and a Kanardia Nesis III digital display.
Investigation Findings
The Taiwan Transportation Safety Board (TTSB) conducted an investigation. The aircraft's electronic flight instrument system (EFIS) recorded data from 1050:28 to 1054:23. On-site examination revealed the throttle at full, fuel shutoff valves open, ignition switches on, but no fuel in the fuel lines and fuel filter. The engine crankshaft was seized. Disassembly of the engine showed that the No. 4 cylinder piston had shattered, with the connecting rod bent and a circlip found loose in the oil sump. The No. 4 cylinder had gouge marks on the wall. Other cylinders appeared normal. Oil analysis showed elevated total acid number (0.41 mg KOH/g) compared to standard (<0.1). Fuel analysis showed research octane number 97.8 (slightly below 98 minimum) and vapor pressure 42.7 kPa (below 45 min). Maintenance records indicated that oil changes had occasionally exceeded the recommended 25-hour interval. The engine had been purchased in June 2018 and installed after the original engine's performance issues.
Pilot and Operations
The pilot held a valid ultralight instructor certificate and had approximately 300 total flight hours. He reported conducting a pre-flight inspection, engine warm-up, and run-up before departure. He noted that the engine had been recently serviced. During the flight, after hearing abnormal engine sounds and seeing a metallic object ejected from the engine, he attempted to find a forced landing site but could not clear obstacles and experienced a stall. He maneuvered to avoid hitting the passenger side, resulting in a crash against a wall.
Conclusion
The investigation did not assign a probable cause in the provided report. The engine failure involved a catastrophic failure of the No. 4 cylinder piston assembly, leading to loss of power. Contributing factors were not analyzed.