On August 9, 2000, at 1345 hours Pacific daylight time, a Cessna 150H, N7011S, experienced a loss of engine power on takeoff. The pilot made an off airport landing in an open field adjacent to the departure end of runway 25 at the Corona Municipal Airport, Corona, California. The airplane became inverted after the nose landing gear dug into soft dirt after touchdown. Alpha Aircraft Group, d.b.a. Corona Flight Academy, operated the airplane under the provisions of 14 CFR Part 91 for the purpose of flight instruction. The airplane sustained substantial damage. The student pilot, on an unsupervised solo, was not injured. Visual meteorological conditions prevailed for the local area instructional flight. A flight plan had not been filed. The airplane was departing at the time of the accident and was scheduled to terminate at Corona. A witness to the accident stated he was in his hangar and heard the airplane takeoff. It did not sound unusual. He then heard the engine cut out and went outside to see what was happening. He saw the airplane about 1/3 the way down the runway below the tree line in a shallow climb attitude. He estimated that the airplane was 30 feet agl. When the airplane passed by his hangar it lost about 10 feet of altitude. He heard the engine come back online and indicated that the pilot continued with the takeoff. The witness reported that the engine sputtered again. The airplane entered a 45-degree bank when he lost sight of it behind a row of hangars. According to the student pilot, he had been signed off the day before the accident for solo flight. The purpose of both flights on the day of the accident was to conduct pattern work. On the first flight of the day, he noted a "slight" loss of power for a second, which he attributed to winds. The engine came back online and he continued the flight. When he returned to land he noted the same loss of power. He shutdown the engine and took a break for a few minutes. When he returned, he conducted another preflight. He visually checked the oil, fuel, and corresponding gages. He determined there was approximately 1/4 tank of fuel. He concluded that there was a sufficient amount of fuel for the intended duration of flight. No discrepancies were noted during the run-up. The student pilot flew once around the pattern, landed, taxied back, and took off again. During the second takeoff, about 200 feet agl, the engine started to lose power. To avoid a stall and a crash into the trees at the departure end of the runway, he aimed for an open field next to the airport. He intended to attempt a soft field landing; however, the field was "too soft." After touchdown, the nose landing gear dug into the dirt and collapsed. The airplane came to rest upside down. A fuel receipt obtained from the Corona airport indicated the airplane had been refueled on August 8, 2000, with 9.179 gallons of fuel. Approximately 4 gallons was on board prior to refueling, which brought the total fuel on board at that time to 15 gallons. Corona Flight Academy flight logs indicate the airplane flew for a total of 2.2 hours the day before the accident. On August 9, the airplane flew for .4 hours prior to the accident flight. According to the manufacturer's owner's manual, a total of 3.5 gallons of fuel is unusable. Fuel burn for this airplane is 3.0 gallons per hour at 1,800 rpm. Eastman Aircraft at the Corona airport recovered the airplane on the day of the accident. Recovery personnel did not observe any wet areas or discolored vegetation beneath the airplane. The fuel system was inspected by a Federal Aviation Administration (FAA) inspector at Eastman's facilities and found to be intact. Approximately 1 gallon of fuel was drained from the aircraft to engine fuel line. On August 16, 2000, the FAA inspector observed the engine removal from the accident airplane and reinstallation on another Cessna 150. This was done to facilitate an engine run. The engine mounts were broken and an engine run could not be conducted on the accident airplane. The original carburetor was reassembled and reinstalled. The engine was primed and the propeller was rotated by hand. An unsuccessful first attempt was made to start the engine. The engine was primed and the propeller was rotated by hand again. The engine started and ran for 1 minute at 1,700 rpm. The test run was terminated due to a leak of the oil filter screen housing. No indications of mechanical or electrical problems were noted with the engine.