Sorrell Hiperlight, 95-0048, Beechwood, New South Wales, on 12 November 1989

Circumstances:

The aircraft was taking off shortly after the pilot had carried out modifications to the fuel system. This had included removing and replacing fuel lines. A witness reported that prior to commencing the take-off, the engine had been misfiring. This had continued during the take-off run and initial climb until the engine stopped at a height of about 150 feet. The aircraft was seen to turn sharply to the left before entering a steep nose down spin. After about one full turn the aircraft struck the ground near the strip end. The pilot, who was not wearing a helmet, suffered a fatal head injury following the failure of his upper body restraint on impact. The reason for the loss of engine power could not be positively determined.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. Undetermined loss of engine power after take-off.

2. Pilot attempted operation with known engine deficiency.

3. Pilot encountered circumstances beyond his capability.

Recommendations:

As a result of the initial investigation, the Australian Ultralight Federation was notified of the failure of the restraint system, together with a recommended solution. The AUF issued an Airworthiness Advisory on the subject in January 1990.