NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The private pilot and flight instructor were performing an instructional cross-country flight to familiarize the pilot with the newly-purchased airplane and return the airplane to the pilot’s home airport. The pilot reported that, during final approach for landing at an intermediate airport, the engine experienced a partial loss of power. He tried to troubleshoot; however, there was insufficient altitude to restart the engine, and the airplane impacted the terrain short of the runway. The nose landing gear collapsed and the airplane came to rest nose-down. The left wing fuel tank contained about 12 gallons of fuel, and the right wing tank was full.
A postaccident examination of the recovered airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The engine was run on the airframe through various power settings to include idle and full power; however, the engine could only be run smoothly at idle after leaning the mixture control. Application of throttle required a richening of the mixture control to obtain full power.
The engine-driven fuel pump, throttle body/fuel metering unit, and the fuel manifold valve were removed and subsequently tested individually. The testing revealed no anomalies that would have prevented these components from operating normally on the engine; therefore, the reason for the partial loss of engine power could not be determined.