Accident Details
Probable Cause and Findings
The pilot’s improper in-flight fuel management, which led to fuel starvation and a total loss of engine power.
Aircraft Information
Registered Owner (Current)
Analysis
On July 26, 2023, about 1730 Pacific daylight time, a Maule M-5-235C, N6201M, was substantially damaged when it was involved in an accident near Eastsound, Washington. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that he departed Columbia Gorge Regional/The Dalles Municipal Airport (DLS), The Dalles, Oregon, with 45 gallons of fuel on board and flew to Orcas Island Airport (ORS), Eastsound, Washington. While at ORS, he determined that there were about 15 gallons of fuel on board, and the left tank had “substantially” more fuel than the right tank. The pilot then took off on a 15-minute sightseeing flight around the island with two friends. He returned to ORS and conducted a second sightseeing flight with a third friend, flying the same flight profile on the second sightseeing flight that he had flown on the first sightseeing flight.
The pilot said that he flew with the fuel selector in the Both position. At the conclusion of the second sightseeing flight, while on final approach to ORS, the engine sputtered, lost fuel pressure, and lost all power. The pilot engaged the electric boost pump but noted no change in fuel pressure. With the total loss of engine power, he thought that he could not make the runway and therefore initiated a forced landing to a field. During the landing, he maneuvered the airplane to avoid power lines, which resulted in the airplane striking a fence and subsequently nosing over and coming to rest inverted. Local law enforcement personnel noted that there was no fuel leaking at the accident site.
The investigation was unable to determine the actual fuel quantity in the airplane’s fuel tanks at the time of the accident because the pilot recovered the airplane wreckage on Orcas Island and then moved it to a secure location on the mainland, without oversight by federal officials. The pilot reported that when the airplane wreckage was recovered, about 10 gallons of fuel were drained. According to the manufacturer, the airplane’s fuel system retains about 3 gallons of unusable fuel.
Examination of the airframe and engine revealed no evidence of preaccident failures or malfunctions that would have precluded normal operation. Fuel continuity was established from the main tanks to the carburetor. The engine-driven fuel pump was removed for examination and no anomalies were noted. When the engine-driven lever was activated, the pump diaphragm operated normally. Additionally, when the electric fuel boost pump was activated, it operated normally with no anomalies noted. The main and auxiliary fuel tanks were examined with a borescope and no anomalies were noted.
Following the wreckage examination, the pilot communicated that he likely ran a fuel tank dry. He also communicated that air may have been introduced into the fuel lines while turning the airplane in maneuvering flight with a low fuel quantity in one of the tanks. When asked how this accident could have been prevented, the pilot said to top off both fuel tanks before departure.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# WPR23LA285