What happened
On January 3, 2009, at approximately 16:30, an Air Creation ultralight weight vehicle, featuring a QUARTZ 18 BI wing, crashed in a pumpkin field near Gaoshu Township, Pingtung County. The aircraft was operating in an unauthorized activity area without prior application.
The pilot and one passenger were performing a series of maneuvers. According to witnesses, the pilot had completed several high-angle dives and pull-ups. During a dive of approximately 45 degrees, the aircraft experienced a sudden deceleration and the wing structure collapsed inward. The vehicle plummeted vertically into a field approximately 300 meters east of the takeoff site. Both occupants sustained fatal injuries.
The investigation
The investigation examined the wreckage of the Air Creation vehicle, which was found destroyed. Investigators analyzed the structural integrity of the wing frame, consisting of aluminum alloy spars and nylon fabric. The examination of the left wing leading edge revealed a fracture pattern consistent with the structure being subjected to negative vertical acceleration (negative G-load).
Furthermore, the investigation found that the propeller had struck the wing fabric during the descent, indicating that the wing structure had collapsed toward the engine while the engine was still running. The investigation also noted that the aircraft lacked airspeed and G-load indicators, making it difficult for the pilot to monitor flight parameters. Additionally, there were no maintenance records, engine installation logs, or valid airworthiness documentation for the aircraft.
Findings
- The pilot performed maneuvers that exceeded the aircraft's specified flight envelope, specifically exceeding the maximum allowable pitch angle of 30 degrees.
- The structural failure of the wing was caused by exceeding the negative vertical acceleration (G-load) limits during aggressive flight maneuvers.
- The aircraft was being operated in an unauthorized airspace and an unapproved landing site.
- The pilot was operating the vehicle without a valid license, and the aircraft was not properly registered or inspected.
- The lack of airspeed and G-load instrumentation prevented the pilot from recognizing when the aircraft had exceeded its structural and aerodynamic limits.