On June 21, 1998, about 1830 Eastern Daylight Time, a homebuilt Narrin-Whittman W-8 Tailwind, N2713C, was destroyed during a take-off roll from Flying M Aerodrome (PA88), Germansville, Pennsylvania. Neither the certificated private pilot nor his passenger were injured. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the personal flight conducted under 14 CFR 91. According to a Federal Aviation Administration (FAA) Inspector, the pilot said the airplane never got off the ground. It ran off the end of the runway, hit grape vines and a tree, then cartwheeled. The pilot thought the wind shifted during the takeoff roll due to a nearby thunderstorm. A witness, who was also the airport owner, stated that there was a mountain about 3,000 feet north of the field, and that a dark cloud was moving along its ridgeline. He said the airplane was on its takeoff roll from Runway 08, with a headwind of about 5 knots. Approximately half-way through the airplane's takeoff roll, he saw the windsock shift, to 5 to 8 knots on the airplane's tail. At 650 to 800 feet from the departure end, the airport owner thought the airplane was not accelerating, and would abort the takeoff. Instead, the airplane continued its roll, eventually off the end of the runway. According to the airport owner, the pilot said he thought the airplane would fly, but ran out of runway.