MIA88FA213

The owner rprtd the plt flew the acft at a company picnic without authorization. Company psnl saw the experimental, amateur built acft takeoff from the company strip, then maneuver for a low pass over the area at about 150 to 200 ft AGL. Some estimated the pass was made with a speed in excess of 100 mph. The never exceed (vne) speed for the acft was 95 mph. As the acft apchd the area of the picnic, witnesses heard a buzzing or fluttering sound. As it continued overhead, witnesses noted the left aileron had become detached from the outboard end & had folded aft. Subsequently, the rgt aileron failed in a similar manner. The acft entered a climb & some witnesses noted a power reduction as if the plt was trying to slow the acft. However, the acft rolled & entered a dscnt which was described as a stall/spin condition. Rprtdly, the plt was aware of the acft's tendency to enctr aileron buzz or flutter when accelerated above 100 mph.