What happened
On June 30, 2007, at approximately 09:00, an unregistered RANS S-6 ultralight aircraft crashed into a field near the Guanshan Railway Station in Taitung County, Taiwan. The aircraft had departed from the Hong'an airfield, an unauthorized operating site, at approximately 08:50.
During the flight, witnesses observed the aircraft performing a steep turn with a bank angle exceeding 45 degrees at an altitude of approximately 200 to 300 feet. Shortly after, the aircraft was seen performing maneuvers that included a rapid loss of altitude. Video evidence captured the final seconds of the flight, showing the aircraft's attitude shifting from a climb to a descent, eventually reaching a near-vertical nose-down position before impacting the ground. The impact resulted in two fatalities, involving the pilot and a US passenger. The aircraft was destroyed upon impact.
The investigation
The investigation examined the aircraft's mechanical systems, including the engine, fuel system, and flight controls. Testing of the Bombardier ROTAX 532 engine revealed that the powerplant was functioning normally, with no evidence of fuel starvation or mechanical failure. The fuel system, including the filters and separators, was found to be unobstructed and free of contaminants. The propeller was still rotating at high speed at the moment of impact, as evidenced by the tension and compression fracture patterns on the blade edges.
Flight control systems, including the roll, pitch, and yaw mechanisms, were all found to be in good working order. The investigation also reviewed the pilot's background and the legality of the flight operations. It was determined that the aircraft was unregistered and the flight took place in an unauthorized airspace. Furthermore, the pilot was operating without a valid ultralight aircraft license and had previously been suspended from a local aviation association due to safety concerns and poor maintenance habits.
Findings
- The pilot failed to maintain sufficient safe altitude during maneuvers, leading to the nose-down impact.
- The aircraft was operating illegally without registration or valid certification.
- The pilot lacked the required ultralight aircraft operator certificate and had not completed the necessary training prescribed by regulations.
- The pilot had a history of unsafe flying habits and poor aircraft maintenance, which had previously led to his exclusion from a local aviation association.
- The occupants were not utilizing all available safety restraints, as they were only wearing lap belts rather than utilizing the shoulder harnesses provided.