Accident Overview
On September 17, 2018, at 1335 Pacific standard time, a Piper PA-24-250, registration N7472P, was substantially damaged in an accident near Upland, California. The pilot and passenger were not injured. The aircraft was operating as a Title 14 Code of Federal Regulations Part 91 personal flight.
Flight Details
The flight originated from Reno/Tahoe International Airport (RNO), Reno, Nevada, around 1115, after the aircraft had been tied down for four days. The pilot performed a preflight inspection on the morning of the accident and noted no discrepancies. The auxiliary fuel tanks were fueled with 20 gallons of fuel, 10 gallons each, and the pilot estimated a total of 75 gallons onboard at departure.
During the flight, the pilot departed with the left main fuel tank selected, estimating about 30 gallons in that tank. After reaching cruise altitude, he switched to the right auxiliary fuel tank and alternated between left and right auxiliary tanks every 30 minutes until about 5 gallons remained in each auxiliary tank. He used the electric fuel pump during each tank change.
Engine Power Loss
Approximately 3.5 nautical miles from the destination airport, the pilot turned on the electric fuel pump and switched to the right main fuel tank. Fuel pressure was steady, and he left the pump on for the remainder of the approach. While on final approach, he noticed an increasing sink rate and increased the throttle, but engine power did not respond. He switched to the left main tank, confirmed the electric fuel pump was on, the ignition switch was on BOTH, the fuel mixture control was full-rich, and the propeller control was at maximum rpm, but the engine did not respond.
Forced Landing
The pilot selected an empty field short of the runway for a forced landing. After touchdown, the aircraft rolled a short distance before the nose landing gear and left main landing gear impacted rocks, causing the airplane to spin about 150 degrees before coming to a stop. The pilot reported wearing noise-cancelling headphones and was uncertain when the partial loss of engine power occurred.
Post-Accident Inspection
A Federal Aviation Administration inspector reported that the main fuel tanks contained approximately 24 to 25 total gallons of fuel. Visual inspection of the engine revealed no holes in the case; valve train and mechanical continuity were established. The oil filter had no carbon deposits, and the fuel screens for both boost pumps were free of debris. The aft boost pump contained about four spoonsfuls of a mixture of fuel and water. Borescope examination of the cylinders showed signatures consistent with a lean fuel/air mixture.