On December 1, 2015, about 1950 mountain standard time, a Pipistrel Virus motorglider, N145VS, was substantially damaged during a forced landing following a loss of engine power near Centennial Airport (KAPA), Englewood, Colorado. The commercial pilot and his passenger were not injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. Night visual meteorological conditions prevailed at the time of the accident. The cross country flight departed Sayre Municipal Airport (3O4), Sayre, Oklahoma, about 1710, was en route to Erie Municipal Airport (KEIK), Erie, Colorado, and diverted to KAPA. While en route, the pilot assessed that the fuel level from right tank was not changing. It did not appear that fuel was draining from the right tank and the fuel remaining in the left fuel tank was not adequate to complete the flight as previously planned. The pilot requested to divert to KAPA and while preparing to land the engine lost power. The pilot performed a forced landing to a field during which the airplane nosed over and came to rest inverted. The lower fuselage and the engine mount were substantially damaged. The airframe, engine, and fuel system were examined under the auspices of the National Transportation Safety Board investigator-in-charge. The sight gauges for the left and right fuel tanks and indicated capacity of the left and right fuel tanks were accurate. Visible contaminants, consistent with insect(s) and leaves, were recovered from the right fuel tank and fuel lines. Once the contaminants were removed fuel flowed freely from the right fuel tank. The examination of the engine, airframe, and remaining systems revealed no anomalies.