WPR22LA213

The pilot reported that, while approaching the destination airport, he moved the fuel selector from the left main fuel tank to the right main fuel tank. About 5 miles from the airport, he completed the before-landing checklist and reduced the engine power setting to 15 inches of manifold pressure while he slowly advanced the propeller lever forward. Shortly after, the engine lost total power. The pilot immediately verified that the position of the mixture was full rich, and that the fuel boost pump was on. The pilot moved the fuel selector lever from the right main tank to left main tank, but then decided to switch back to the right main tank, as the right tank contained more fuel. The engine briefly started, but again lost all power. The pilot initiated a forced landing to an open field and the airplane impacted a dirt berm during the landing roll, resulting in substantial damage to the right wing. Postaccident examination of the engine and engine systems revealed no evidence of preimpact mechanical failure or malfunction. Examination of the fuel supply and fuel vent systems revealed no evidence of blockage, and the fuel selector functioned normally when tested. At the accident site, the left main fuel tank contained about one gallon of fuel; the right main, right auxiliary, and left auxiliary tanks all appeared full. Additionally, the pilot reported that he examined the fuel tanks immediately after the accident; the right tank was full, and he could not see any fuel in the left main tank. Although the environmental conditions at the time of the accident were favorable for serious carburetor icing at glide power or reduced power settings, the pilot reported that he reduced engine power for landing just before the loss of power occurred; therefore, the airplane had not been operating at reduced power settings for an extended period of time; therefore, it is unlikely that carburetor icing resulted in the interruption of the fuel flow. Although the pilot’s statement indicated that he switched fuel tanks several minutes before the loss of engine power, given the distribution of the fuel in the tanks following the accident and the lack of any mechanical anomalies found during postaccident examination, it is most likely that the pilot exhausted the available fuel in the left main tank, resulting in fuel starvation and a total loss of engine power.

On June 11, 2022, about 1836 Pacific standard time, a Piper PA-24-250, N7428P, was substantially damaged when it was involved in an accident near Auburn, Washington. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The total flight time was about 1 hour, and the pilot reported that, about 18 nautical miles from the destination airport, he moved the fuel selector from the left main fuel tank to the right main fuel tank. About 5 miles from the airport, he completed the before-landing checklist and reduced the engine power setting to 15 inches of manifold pressure while he slowly advanced the propeller lever forward. Shortly after, the engine lost total power. The pilot immediately verified that the position of the mixture was full rich, and that the fuel boost pump was on. Simultaneously, the pilot moved the fuel selector from the right main tank to left main tank, but then decided to switch back to the right main tank, as the right tank contained more fuel. The engine briefly started, but again lost all power. The pilot initiated a forced landing to an open field, and during the landing roll, the airplane impacted a dirt berm, resulting in substantial damage to the right wing. Following the accident, the pilot powered the airplane, moved the fuel selector to the right main tank and turned the electric fuel pump on. Initially, he heard the pump cavitate, but then saw the fuel pressure gauge indicate an increase in fuel pressure. He then turned the power off and placed the fuel selector valve back in the off position. He stated that, in his visual inspection of the fuel tanks after the accident, he could not see any fuel in the left main tank, but the right main tank contained “plenty of fuel.” Postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies. The right main fuel tank, right auxiliary tank, and left auxiliary tank all appeared full of fuel. The left main fuel tank was not breached and contained about one gallon of fuel. The fuel system was traced from each wing tank to the carburetor through the fuel selector, which rotated normally and was unobstructed. The fuel selector was in the off detent when first viewed. Detents were felt at the fuel selector for all four positions (right and left main tanks and left and right auxiliary tanks). The fuel selector was then positioned to each tank position and fuel was seen escaping the fuel strainer/drain. The detents were audible and could be felt. The fuel supply and vent lines in both wing fuel tanks were free of obstructions. The carburetor was disassembled, and the bowl contained about 5 ounces of fuel; the metal floats were intact and undamaged. The fuel in the carburetor bowl was tested using water finding paste and no water was detected. The accelerator pump functioned when the throttle lever was actuated, and the needle valve and seat functioned when the float wasmoved by hand. Mechanical continuity was established throughout the engine rotating group, valvetrain, and accessory section when the crankshaft was manually rotated at the propeller. Thumb compression was achieved at all six cylinders and the valves displayed normal lift when the crankshaft was rotated. Examination of the cylinders’ combustion chambers using a lighted borescope revealed normal piston face and valve signatures, and no indications of catastrophic engine failure. Weather conditions recorded at Seattle-Tacoma International Airport (SEA), Seattle, Washington, at 1753 and 1853 (about 43 minutes before the accident and about 17 minutes after the accident, respectively) indicated that the temperature and dew point were 20°C and 9°C. A review of the carburetor icing probability chart contained in Federal Aviation Administration Special Airworthiness Information Bulletin (SAIB) CE-09-35, Carburetor Icing Prevention, indicated that based on the reported temperature and dew point around the time of the accident, the conditions were favorable for serious icing at glide power.