On August 7, 2009, about 1743 eastern daylight time, a Piper PA-28-161, N20977, was substantially damaged during a forced landing at Winchester Regional Airport (OKV), Winchester, VA. The certificated private pilot and the passenger both incurred minor injuries. Visual meteorological conditions prevailed at the time of the accident, and there was no flight plan filed for the local personal flight, which was conducted under the provisions 14 Code of Federal Regulations Part 91. According to the pilot, the accident flight was intended to be a sightseeing flight of the Winchester and Shenandoah area. The pilot stated that he completed a preflight inspection of the airplane according to the checklist provided by the operator, from whom he rented the airplane. During the inspection he "sumped" fuel from each fuel tank, as well as the gascolator, and found no water or debris. When asked, the pilot was unable recall the exact quantity of fuel in the tanks during the preflight inspection. Before takeoff, the pilot performed a complete engine run-up procedure and noted no abnormalities. The pilot then departed OKV, about 1615, and flew the airplane between 1,500 feet and 2,000 feet above ground level. While returning to OKV, about 3 to 5 miles south of the airport, and positioning the airplane for a 45-degree entry to the traffic pattern, the engine power decreased from "full to idle power." The pilot then turned directly to the airport and "worked through emergency procedures." The pilot repeated the emergency procedures three times during the descent, and each iteration resulted in a surge to full power, and then a return to idle power. After the third attempt, he could not tell if the engine was idling or if the propeller was just "wind-milling." The pilot subsequently performed a forced landing, and the airplane came to rest about 1,200 feet prior to the runway threshold. During the landing, the airplane struck a fence, resulting in substantial damage. According to the pilot, he held a private pilot certificate with a rating for airplane single-engine land. He reported 227 total hours of flight experience, 38 hours of which were in the accident airplane make and model. The weather reported at OKV, at 1800, included winds from 220 degrees at 4 knots, visibility 10 statute miles, clear skies, temperature 26 degrees Celsius (C), dew point at 11 degrees C, and barometric pressure at 30.15 inches of mercury. Airport and aircraft recovery personnel reported that both fuel tanks were compromised during the accident sequence, but there was no odor of fuel and no evidence of fuel spillage at the accident scene. The engine was test-run on October 8, 2009, under the supervision of an NTSB investigator. Fresh fuel was plumbed to the engine at the firewall. The engine started without hesitation and ran at various power settings for about 2 minutes, until the test was ceased. During the test-run, engine operation was smooth and continuous with no abnormalities noted. According to fueling records maintained by the operator, the airplane was last fueled on July 30, 2009. While the exact amount of fuel added to each fuel tank was not recorded, nor was the total fuel state of the airplane following the fueling, the operator's Director of Maintenance stated that the standard procedure for linemen at OKV was to "top-off" airplanes with fuel, unless otherwise instructed. The airplane was on its third flight and had accumulated 4.2 total hours of flight time since the last fuel service. According to the Piper PA-28-161 Pilot’s Operating Handbook, the airplane contained two 25 gallon fuel tanks, 1 gallon of which was unusable in each tank. Fuel consumption calculations using data from the handbook revealed that at power settings between 55 and 75-percent power, and between best power and best economy fuel flow settings, the airplane would have an expected cruise endurance of between 4.8 and 5.6 hours. The calculation was for cruise endurance only, and did not take into account fuel burned during taxi, run-up, takeoff, climb, descent, or landing.