Primary finding
Probable cause
A total loss of engine power during takeoff as a result of fuel starvation.
Investigator assessment
Analysis narrative
The pilot reported that he had experienced an intermittent fuel pressure fluctuation and rough-running engine during a previous flight, but that the condition was not present during a subsequent test flight with a mechanic. Before departing on the accident flight, the pilot visually checked the airplane’s fuel quantity; he reported that the main fuel tank contained about 6 gallons of fuel and the auxiliary tanks contained about 12 to 14 gallons of fuel. The pilot reported switching from the main tank to the auxiliary tank during the initial climb. Shortly thereafter, during the crosswind turn about 300 ft above ground level, the engine abruptly lost power. During the ensuing forced landing, the airplane struck trees and came to rest in a field. Postaccident examination found the fuel selector positioned to the main tank, which was depleted, while about 10 gallons of fuel remained in the auxiliary tanks. Postaccident examination of the engine revealed no anomalies, and the fuel system remained intact with no evidence of leakage. Additionally, a service bulletin issued by the airplane type certificate holder indicated that the auxiliary fuel tank should not be used for takeoff or landing to reduce the possibility of an inadvertent loss of engine power. Based on the available information, it was likely that the loss of engine power was the result of fuel starvation.
Source record
Factual narrative
On June 8, 2024, about 0645 central daylight time, a North American Navion airplane, N91173, was substantially damaged when it was involved in an accident near Tullahoma, Tennessee. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he had experienced an intermittent fuel pressure fluctuation and rough-running engine during a previous flight. He reported that the condition was not present during a subsequent test flight with a mechanic. Before departing on the accident flight, the pilot visually checked the airplane’s fuel quantity; he reported that the main fuel tank contained about 6 gallons of fuel and the auxiliary tanks contained about 12 to 14 gallons of fuel. The pilot reported that the takeoff was normal. After takeoff, he retracted the landing gear and flaps, reduced engine power, turned the fuel boost pump on, and reported switching from the main fuel tank to the auxiliary fuel tank during the initial climb. Shortly thereafter, during the crosswind turn about 300 ft above ground level, the engine abruptly lost power. The pilot attempted to restore engine power, and the engine briefly regained power before losing power again. The pilot then performed a forced landing to a field near the airport. The airplane impacted trees and came to rest upright in the field. The pilot reported that he shut off the fuel and electrical power before exiting the airplane. Postaccident examination of the engine performed by an FAA inspector revealed no anomalies that would have precluded normal operation. Examination of the wreckage revealed that the fuel system and tanks remained intact with no evidence of leakage or spillage. Approximately 10 gallons of 100LL aviation fuel remained in the auxiliary tanks, while the main fuel tanks were depleted of fuel. The cockpit fuel selector was found positioned to the Main tank. A service bulletin issued by the airplane type certificate holder indicated that the auxiliary fuel tank should not be used for takeoff or landing to reduce the possibility of an inadvertent loss of engine power.