On July 31, 1999, about 1430 eastern daylight time, a Piper, PA24-250, N5801P, was substantially damaged while landing at the Cumberland Valley Airstrip Airport, Greencastle, Pennsylvania. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed the Williamsport Regional Airport, Williamsport, Pennsylvania, about 1330. The personal flight was conducted under 14 CFR Part 91. The airplane was landing on runway 09, a 1,800 foot long, 150 foot wide, turf runway. In a telephone interview, the pilot stated he conducted a short field approach to the runway. On final approach, the airplane's flaps were fully extended and the pilot maintained an airspeed of 80 miles per hour. When the airplane was above the runway threshold, the pilot pulled the power back; however, the airplane "floated" about 1,000 feet down the runway. The pilot then retracted the flaps and the airplane touched down. The pilot stated that braking action on the runway was poor, and when he noticed the airplane was approaching the trees located at the end of the runway, he intentionally "ground-looped" the airplane. The airplane's left main landing gear collapsed, and the left wing contacted the runway. The pilot did not report any mechanical malfunctions of the airframe or engine. The pilot reported about 1,150 hours of total flight experience, of which 970 hours, were in the accident airplane.