At 16:15 eastern time, a Grumman American AA-5B was damaged during taxi at the Donegal Springs Airpark. The pilot was not injured. The pilot said he preflighted the airplane and found no anomalies. Then he taxied the airplane to runway 27 for departure but, as he attempted to turn onto runway 27, the right brake failed and the airplane traveled off the end of the runway and down a 10-foot embankment. Inspection of the airplane revealed the right brake lining was worn, and there was a hole in the right brake cylinder which was leaking hydraulic fluid.