What happened
On July 8, 2018, at approximately 16:10, a Skylark IIS ultralight aircraft carrying two occupants departed from the Ri-guang landing field in Hualiente, Taiwan. During the flight, while the pilot was performing a standard four-leg approach pattern, the aircraft lost control and crashed into a field northeast of the landing site. The impact resulted in two serious injuries and the total destruction of the aircraft.
At the time of the accident, the wind was blowing from the southeast at approximately 6 knots, and the aircraft was flying at an altitude of about 300 feet.
The investigation
The investigation examined the aircraft, the flight site, and video footage captured by a passenger's mobile phone. Investigators found that the Skylark IIS was a homebuilt aircraft manufactured by Aerospace Industrial Co., Ltd., but it lacked a valid airworthiness certificate from the Civil Aeronautics Administration (CAA). Furthermore, the aircraft had no flight manual detailing operating procedures or performance limitations, and there were no maintenance or usage records available for the airframe or the Rotax 582 UL engine.
The landing site, Ri-guang landing field, was also found to be an unauthorized operating site. Although applications for the site had been previously submitted, the CAA had rejected the use of the location because the land was designated for resort use rather than ultralight aviation activities.
Findings
- The aircraft was operating without a valid airworthiness certificate.
- The pilot was performing a steep turn at a low altitude without a full understanding of the aircraft's specific performance limitations.
- The aircraft lacked a flight manual to guide proper operating procedures.
- The flight was conducted from an unauthorized landing site.