19980801019301A

Acft laned on top of N4451R, on final approach at 3 feet off the ground, both aircraft collided on short final approach to the runway. Examination of both aircraft disclosed that the YAK-55M descended on top of the Cessna 172 while over the threshold. The pilot of the YAK-55M stated that he was returning to the field after practicing aerobatic maneuvers and entered left traffic for runway 15 by crossing over the runwaf at midfield. As he overflew the runway he heard an aircraft call on final approach for runway 15 over the CTAF. He observed an aircraft on a 1/2 mile final and followed that aircraft on a short turning base to final approach. As he rolled out on final and prepared to flare, he felt the collision with an unseen aircraft. The pilot of the Cessna 172 stated that he was in the traffic pattern practicing takeoffs and landings. He said that he called on the CTAF number three for landing behind a Cessna 150 and extended his pattern slightly to allow time for that aircraft to clear the runway. The pilot also reported that he announced his position while on base and final approach. Just as he was flaring the aircraft, he felt a jolt and the aircraft was forced down onto the runway. The pilot of a Cessna 150 in the pattern behind the Cessna 172 stated that he was on downwind when the YAK-55M crossed over the field and cut him off while turning on downwind. The witness reported that the YAK-55M nearly hit his aircraft.