On August 29, 2001, at 1615 eastern daylight time, a Grumman American AA-5B, N28665, was substantially damaged during taxi at the Donegal Springs Airpark (N71), Marietta, Pennsylvania. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. A Federal Aviation Administration (FAA) inspector interviewed the pilot immediately after the accident. According to the inspector, the pilot said he knew the right brake was "soft" prior to his departure. He also said he tested the brakes during a taxi test, and the right brake was "still soft, but he felt it would be ok for this flight." During a telephone interview, the pilot reported that as he attempted to turn the airplane onto runway 27 for departure, the right brake "failed," and the airplane traveled off the end of the runway and down a 10-foot embankment. An FAA inspector performed an on-scene examination of the airplane. According to the inspector, the right brake lining was worn "significantly," which permitted the brake cylinder to extend beyond its limits, and the brake fluid to seep past the cylinder seal. Examination of the airplane logbooks revealed that the last annual inspection was performed on September 4, 2000. No maintenance had been performed to the brakes since that date. Additionally, the pilot did not respond to several requests made to obtain the NTSB Pilot/Operator Aircraft Accident Report.