NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The private pilot/owner had not flown for about 4 years and was receiving a flight review from the flight instructor. The airplane was most recently flown about 4.5 months before the accident and was fueled about 1 month before the accident.. Witnesses reported that during an initial engine run-up before takeoff, the engine ran rough, but during a second run-up, the condition was resolved. According to witnesses, the airplane’s first takeoff was aborted for unknown reasons; during the second takeoff, they heard “popping” sounds before and engine sputtering just after the airplane rotated and began to climb. One witness reported that the engine lost power momentarily while adequate runway remained available to abort the takeoff. However, the pilots elected to continue the takeoff, and the airplane subsequently experienced additional intermittent engine power interruptions. The witnesses reported that the airplane was about 0.5 mile west of the airport, in a slight nose-up attitude, when the left wing dropped. It then entered a spin, impacted the ground in a residential area, and was partially consumed by a postcrash fire.Postaccident examination of the airframe and engine did not reveal evidence of any preimpact malfunctions; however, extensive fire damage precluded operational testing of the ignition and fuel system components. The No. 4 cylinder exhaust value was stuck; however, it was likely a result of the postcrash fire. Although the gascolator drain valve was found in a partially locked position, the valve’s position at impact could not be determined. The reason for the engine sputtering and then resuming normal operation several times as reported by the witnesses could not be determined. In addition, it could not be determined why the flight instructor and pilot/owner elected to continue the takeoff after the airplane experienced an engine malfunction with ample runway remaining to abort the takeoff.