Event Summary
During cruise flight, the pilot reported to an air traffic controller that the airplane was experiencing engine fuel pressure problems. The controller advised the pilot of available airports for a possible landing and asked for the pilot's intentions. The pilot chose to continue the flight. About seven minutes later, while the airplane was at approximately 7,000 feet above ground level, the engine lost total power again, and power was not restored for the remainder of the flight. The pilot attempted to glide to an airport about 10 miles away, but the airplane crashed in a field about three miles from the airport.
Flight Data Analysis
GPS data recorded by an onboard avionics system indicated that the engine had momentarily lost total power about 20 seconds before the pilot reported the problem to the controller. The data showed a loss of fuel pressure before each of the engine power losses and prolonged lateral g forces consistent with a side-slip flight condition. The GPS and flight data indicated that the lateral g-forces increased as the airplane leveled off and accelerated, suggesting that the automatic rudder trim feature of the yaw damper system was either not engaged or not operating. The recorded data indicated autopilot engagement, which should have automatically engaged the yaw damper; however, the data indicated the yaw damper was not engaged. The yaw damper could have subsequently been turned off by several means not recorded by the avionics system.
Mechanical Findings
The rudder trim tab was found displaced to the left about 3/8 inch. Flight testing and recorded flight data revealed that this displacement was consistent with that required to achieve no side slip during a typical climb segment. Testing of the manual electric rudder (yaw) trim system revealed no anomalies, indicating that the pilot would have been able to trim the airplane using the manual system. It is likely that the pilot's failure to properly trim the airplane's rudder led to a prolonged uncoordinated flight condition. Although the fuel tank system is designed to prevent unporting of the fuel lines during momentary periods of uncoordinated flight, it is not intended to do so for extended periods. Therefore, the fuel tank feed line likely unported during the prolonged uncoordinated flight, resulting in the subsequent loss of fuel pressure and engine power.
Glide Performance
The propeller and propeller controls were not in the feathered position, so the windmilling propeller increased the airplane's descent rate during the glide. The glide airspeed used by the pilot was 20 knots below the airspeed recommended by the Pilot's Operating Handbook (POH), and the reduced airspeed also increased the descent rate. The flight and GPS data indicated that the airplane had a gliding range of about 16 nautical miles from the altitude where the final loss of engine power occurred; however, the glide performance depended on several factors, including feathering the propeller and maintaining the proper airspeed, neither of which the pilot performed. Although the POH did not contain maximum range glide performance data with a windmilling propeller, based on available information, it is likely that the airplane could have glided to the alternate airport about 10 miles away if the pilot had followed proper procedures.