On August 27, 2013, about 1708 Hawaiian standard time, an American Champion, 8KCAB, N413JJ, experienced a forced landing following a reported loss of engine power, near the Wheeler Army Airfield (PHHI) Wahiawa, Hawaii. The airplane was registered to J3 Engineering LLC, and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The commercial pilot sustained minor injuries and the passenger was seriously injured. The airplane sustained substantial damage to the wings, fuselage, and vertical stabilizer during the impact sequence. Visual meteorological conditions prevailed and no flight plan had been filed for the personal flight. The local flight originated at Honolulu International Airport, Honolulu, Hawaii, about 1655. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge, the pilot reported that the engine lost power about 30 seconds after completing an Immelmann acrobatic maneuver, while in straight and level flight, about 4,000 feet above ground level. The pilot stated that the airplane did not exceed the 2 minute inverted flight limitation. Despite repeated attempts, the pilot was unable to restart the engine. The pilot requested to land at PHHI. While on approach, the pilot realized that the airplane would not be able to make the runway, and he turned right, into a clearing. During the landing roll, the airplane nosed over and came to rest inverted, in a field about 1 mile from PHHI. Postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector the following day revealed that no pre-impact anomalies with the airframe were observed. Continuity from the cockpit engine controls to the engine was established. The engine visually appeared to be intact and undamaged. No fuel was observed leaking from the airplane, and there was no evidence of fuel causing discoloration on the ground. According to the FAA inspector, the fuel header tank had about 3/4 of a gallon of fuel (half full). The main tanks fuel quantity levels were unable to be determined since the airplane was inverted. Several days later, the airplane was recovered to a local storage facility for further examination. An FAA inspector observing the recovery reported that a small amount of fuel was visible in each main fuel tank, and the tanks were intact, once the airplane was turned right side up, and prior to transport of the wreckage. The inspector stated about 1-2 gallons of fuel was observed in one main tank, and a small amount in the other. However, it could not be ascertained if fuel had leaked from the airplane while it was inverted. The airplane is equipped with two main tanks and a header tank totaling 40 gallons of fuel, of which 39 gallons is specified as usable. The fuel selector valve has two positions, on and off. According to The Pilot Operating Handbook, a limited amount of fuel is provided while inverted, by a 1.5 gallon header tank. The outlet from the header fuel tank consists of a standpipe located at the center of the tank, which allows for half of the tank capacity to be used while in the inverted position. Examination of the engine and airframe by a certified airframe and powerplant mechanic, under the supervision of an FAA inspector, reported that a quart or two of fuel was drained from each main tank, while the wings were stored in a horizontal position/leading edge down position. The gasolator fuel was clear and the screen was clean. No evidence of any internal damage to the engine or accessories was observed. A propeller was installed to facilitate the engine run due to impact damage of the propeller that was installed during the time of the accident. The engine was subsequently test run. The engine functioned normally throughout a various range of power settings. During the test run, fuel was provided through a line secured onto the inlet of the electric driven fuel pump. The certified mechanic stated that the engine started up right away and ran smooth once a fuel source was established, and that he observed no engine anomalies. A multi-functional display unit was removed from the airplane and shipped to the NTSB Recorders laboratory for data download. Review of the data revealed that the accident's flight data was unreliable and did not provide any accurate information. Review of the airplane's maintenance records revealed that the engine and airframe underwent their most recent 100-hour inspection on September 14, 2012, at an engine total time since new of 778 hours and airframe total time of 778 hours. A review of the pilot's fuel logs in comparison to flight times and refueling intervals was accomplished. One potential error was observed on July 12, 2013, where the standard parameter of flight time was not used in the calculation (airplane tachometer time was used instead) which resulted in 0.3 gallons of fuel not appropriately accounted for. The airplane flew 2.9 flight hours since its last refueling on Aug 24, 2013. A fuel purchase invoice of the airplane's last refueling, showed 15.2 gallons of fuel was purchased and according to the pilot's fuel logs, a total of 30.4 gallons of fuel, remained in the airplane at that time. The pilot's fuel logs used 7.38 gallons per hour as the airplane's average fuel burn. The airplane manufacturer's Pilot Operating Handbook, cruise performance at 5,000 feet mean sea level, showed that the fuel flow ranged between 7.6 to 12.0 gallons per hour used, depending on the engine's revolutions per minute (rpm) and manifold pressure settings.