On April 29, 2004, about 1030 Pacific daylight time, a Piper PA-20, N7631K, registered to and operated by the pilot as a 14 CFR Part 91 personal flight, nosed over during the landing roll at Bandera State airstrip, located 11 nautical miles east of North Bend, Washington. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was substantially damaged and the commercial pilot, the sole occupant, was not injured. The flight originated from Renton, Washington, about 30 minutes prior to the accident. During a telephone interview and subsequent written statement, the pilot reported that while in flight, he heard a "flapping sound" and since he was near Bandera State, he decided to land to check the aircraft. The pilot stated that when he was abeam the windsock, which is located near mid-field, he noted that the sock was limp. Since he was already on the downwind for runway 26, he continued in the pattern for landing. The pilot reported that the aircraft was a little high on final approach, so he slipped the aircraft to attain the correct altitude. Just prior to touchdown, the pilot felt a tailwind gust which pushed the aircraft. The pilot continued the landing and the aircraft touched down about one-third of the way down the airstrip. The aircraft rolled for a short distance then became airborne again, subsequently touching down about three-quarters of the way down the airstrip. During the landing roll, the pilot stated that, "...a combination of rough field, tailwind, and braking led to the tail coming up past the point of no return, and on her back we went..." The aircraft then nosed over and came to rest inverted. After the accident, the pilot noted that the winds were mostly light, "...except for the occasional extended gusts of 8-12 knots out of the east." Bandera State airstrip is 2,344 feet long by 100 feet wide and turf covered. Runway alignment is 08-26. The strip is owned and maintained by Washington State Department of Transportation. A representative of Washington State Aviation Division reported that the airstrip was still closed for the winter. One windsock is located at about mid-field.