DURING TAKEOFF, THE GYROPLANE WAS SEEN CLIMBING IN A STEEP ATTITUDE, FOLLOWED BY OSCILLATIONS ABOUT THE LATERAL AXIS. THESE EXCURSIONS INCREASED IN SEVERITY AND THE ROTOR BLADE RPM DETERIORATED. AFTER ABOUT THREE OSCILLATIONS, THE GYROPLANE ROLLED TO THE LEFT AND TUMBLED TO THE GROUND FROM AN APPROXIMATE HEIGHT OF 125 FT. INSPECTION OF THE WRECKAGE REVEALED EVIDENCE OF DOWNWARD ROTATIONAL FLAPPING MOTION OF THE ROTOR BLADES. CORRESPONDING IMPACT MARKS SHOWED THAT THE ROTOR BLADES STRUCK THE TIPS OF THE PROPELLER BLADES AND THE VERTICAL STABILIZER/RUDDER. THE VERTICAL STABILIZER/RUDDER HAD SEPARATED IN FLIGHT AND WAS FOUND ABOUT 75 FT FROM THE MAIN WRECKAGE. THE PILOT WAS NOT RATED IN GYROPLANES OR ROTORCRAFT; HE HAD RECEIVED 2 HOURS OF DUAL INSTRUCTION IN A GYROPLANE OVER SIX MONTHS PRIOR TO THE ACCIDENT; HE HAD NOT BEEN ENDORSED FOR SOLO FLIGHT. ALTHOUGH THE AIRCRAFT WEIGHT AND SPEED PLACED IT IN THE CATEGORY OF AN AIRCRAFT, IT WAS NOT REGISTERED.