WPR26LA065

The pilot of the airplane reported that he was conducting a round-trip cross-country flight from his home airport to another airport. The pilot departed his home airport with full fuel tanks (26 gallons of fuel, of which 3.5 gallons were unusable) and he estimated it would have provided about 4.5 hours of flight time for the flight. Upon arrival at the destination airport, the pilot observed both fuel gauges at about 3/4 of a tank, he however, did not visually verify or measure the fuel levels in either tank. The pilot initially stated that his flight time on the outbound leg was approximately 2 hours, 10 minutes. However, he later reported that it was about 1.5 hours. He added that during the return portion of the flight at an altitude of about 8,500 ft mean sea level, the airplane encountered stronger-than-anticipated headwinds, that resulted in a reduced ground speed. He added that he also encountered up and down drafts, which resulted in him adding power and enriching the mixture to maintain altitude and airspeed. As the airplane approached the destination airport, the engine began to lose power and subsequently experienced a total loss of engine power. The pilot reported that he was unable to restore engine power and initiated a forced landing on an unlit road. During the landing flare, he realized that the road had turned, and he subsequently landed in a vineyard. The airplane struck multiple metal ground stakes, which resulted in substantial damage to both wing struts and horizontal stabilizers. The pilot added that for fuel planning purposes, he used his prior experience operating the accident airplane to estimate fuel consumption. Recorded ADS-B data for the initial flight spanned about 1 hour, 20 minutes, and started about 1.5 nm south of the departure airport and ended about 9.5 nm west of the destination airport. ADS-B data for the return flight spanned about 2 hours, 10 minutes, and began about 12 nm west of the departure airport and ended about 6 nm east of the accident site. According to the airplane’s cruise performance chart, at a cruise altitude of 7,500 ft and a power setting of 2,700 RPM, and a lean mixture, the airplane’s cruise endurance was approximately 4.1 hours. The chart also noted that the endurance and range calculations did not include allowances for takeoff or fuel reserve. Additionally, the cruise performance chart did not include fuel burn calculations for a climb from takeoff to a cruise altitude, which is however provided in the maximum rate of climb data chart. Postaccident examination of the airplane revealed no evidence of any pre-accident mechanical malfunctions or failures that would have precluded normal operation. The fuel tanks or fuel lines were not breached. The left fuel tank contained about 4 ounces of fuel and the right fuel tank contained about 1/4 gallon of fuel.