ANC83FU002

Reportedly, the plt took off from a yard, and when the ultralight vehicle had climbed to about 200 ft AGL, the eng lost RPM momentarily, then regained power. A witness reported that when the RPM decreased, the ultralight nosed over & went upside down. During the sequence, the wings folded & the vehicle fell to the ground. No mechanical irregularities of either the engine or airframe were found. An associate, who was flying in another ultralight, stated that the normal procedure for a loss of power would be to lower the nose to gain airspeed. He stated that in a weight shift control vehicle, such as this was, the response would be immediate. He further reported that should the eng regain power, while the plt's weight was shifted forward, the thrust would push the nose further forward (down). He also stated that the plt may not have completely removed frost from the canard, and if the canard loses lift, the nose would drop.