The pilot reported that, during preflight preparations, he filled the airplane's fuel tanks to 50 gallons total onboard and planned to switch the fuel tanks at "+1 hour and +3 hours" during the flight. He added that he departed with the fuel selector on the right tank. One hour into the flight, he switched to the left fuel tank.
While descending to land at the destination airport, 3 hours and 10 minutes into the flight, he set the mixture at full rich and turned the fuel pump on. The engine "immediately lost power" and the "RPM's fell to 1000-1200 and ran smooth until [the] engine quit." He then began an emergency checklist and began to troubleshoot to no avail. He navigated to an area to make an off-airport landing on a road. Upon landing, the right wing impacted brush and weeds, the airplane veered right and came to rest in a ditch.
The pilot reported that each fuel tank contained 24 gallons of usable fuel and his estimated fuel burn was 10 gallons per hour.
The airplane sustained substantial damage to the right wing.
The Federal Aviation Administrator inspector who examined the airplane reported that the fuel selector valve was set to the left fuel tank. Magnetos were found off with no key in the ignition switch. The propeller and engine cowl showed minimal damage and no fuel was found in the engine fuel sump. The left wing appeared undamaged with less than a quart of fuel remaining in the tank. The right wing exhibited extensive aft crushing damaged to the outboard leading edge and the fuel line was crimped and broken by impact forces with no fuel remaining in the wing tank.
The airplane manufacturer's pilot's operating handbook, provided information and guidance in a section titled " ENGINE POWER LOSS IN FLIGHT" which stated in part:
Fuel selector: switch to tank containing fuel
Electric fuel pump: ON
Mixture: RICH
Carburetor heat: ON
Engine gauges: check for indication of cause of power loss
Primer: check locked. If no fuel pressure is indicated check tank selector position to be sure it is on a tank containing fuel.