Background
The pilot had accumulated 484 total flight hours, with 44 hours in the accident make and model, including 25 hours as pilot-in-command. He completed a cross-country flight of about 2 hours and 20 minutes.
Event
After beginning his descent, the pilot pulled the knob to start fuel transfer from the reserve (auxiliary) tank. He entered the airport pattern, flew one circuit to check the wind sock, then turned onto the base leg. Shortly after turning onto final approach, the engine lost power. The pilot immediately checked the fuel selector, advanced the throttle to full, and checked the propeller control, mixture, and booster pump (set to high boost). Determining he could not reach the runway, he braced for a crash landing. The airplane struck trees and fell to the ground.
Investigation Findings
Post-accident examination of the engine revealed no discrepancies. Fuel calculations indicated that the fuel consumption for the flight would have nearly exhausted the main tanks. The main tanks were near empty when the pilot switched to the auxiliary tank. The auxiliary tank was gravity-fed into the right main tank, not directly to the selector valve. During a steep bank turn from base leg to final, the small amount of fuel in the auxiliary tank shifted to the low side of the tank, preventing fuel flow to the accumulator tank. Placards in the airplane specified that the auxiliary tank was to be used only in straight and level flight. The aircraft's Type Certificate Data Sheets (TCDS) preclude operation of the auxiliary tank except in straight and level flight; it is not approved for takeoff or landing.