LAX83FU007

The plt was on a familiarization flt in preparation to fly the ultralight vehicle on a x-country to evaluate it for a magazine article. The eng quit on the 1st flt & a successful forced landing was made. Reportedly, the vehicle required only minor repairs & a test flt by a company plt was declined by the plt prior to his 2nd & last flt. After the 2nd takeoff, the vehicle was observed to climb in a right traffic pattern. On downwind at aprx 500 ft AGL, the vehicle nosedover into about a 20 deg dive. It then accelerated & power was maintained well into the dive, even after if approached 40 deg. The vehicle then went into a slow left bank & impacted. The power was reduced before impact. The airspeed was estimated well above the 'never exceed' speed. An exam of the wreckage revealed no evidence of a preimpact structural orcontrol failure. Reportedly, the vehicle was somewhat nose heavy, but no wt & balance data was available. Also it was reported that the plt wore contact lenses & previously had problems with his goggles coming off & landing in his lap.