The airplane was substantially damaged during a forced landing following loss of engine power at 1450 Eastern time. The private pilot and the passenger received minor injuries. Visual conditions prevailed for the local post-maintenance test flight. After takeoff, the flight remained in the traffic pattern. When the airplane was on the downwind leg and 45 degrees from the approach end of the landing runway, the pilot reduced engine power to 1500 rpm and extended the pattern for traffic. While turning base, the pilot attempted to add power but the engine did not respond. He elected to make a forced landing in an open field. During the landing roll the empennage and engine separated from the fuselage. The pilot and the passenger exited the airplane without assistance.
