Preflight and Departure
During a preflight inspection, the pilot checked the fuel tanks and observed that the fuel level reached the bottom of the filler neck, which the pilot considered appropriately full. After starting the engine, fuel began leaking from the fuel sump drain hose. The pilot then operated a spring-loaded valve handle inside the airplane, which apparently stopped the leak.
In-Flight Events
Shortly after departure, the engine began running rough. The pilot initiated a deviation to another airport. During the diversion, the engine resumed smooth operation, and the pilot decided to continue toward the original destination. However, during descent, the engine again began running rough. The pilot concluded that the fuel tanks had been exhausted and performed a forced landing, which resulted in substantial damage to the aircraft.
Fuel Calculations and Examination
The airplane's cruising endurance, based on 75% power and 90 gallons of fuel on board, is 5.4 hours. However, the usable fuel capacity when the tanks are filled to the bottom of the filler necks is approximately 80 gallons. The actual flight time of this aircraft was 5.55 hours. A Federal Aviation Administration inspector examined the airplane and found only residual fuel in the selector valve; no leaks were detected in the fuel system.