On July 22, 2000, about 1140 mountain daylight time, a Cessna 180H, N2780X, registered to and operated by the pilot as a 14CFR91 personal/pleasure flight sustained substantial damage while landing at Friedman Memorial Airport, Hailey, Idaho. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the cross-country flight. The flight originated from Yellow Pine, Idaho, approximately 50 minutes prior to the accident. There was no fire and no report of ELT activation. The pilot reported that the airplane touched down, in a three-point attitude, on runway 13. He stated that when he applied the brakes, the right main locked-up and the airplane subsequently ground looped. Substantial damage was reported to the airplane's left wing. At 1155 MDT, Hailey winds were from 200 degrees true at 12 knots. At the request of the National Transportation Safety Board, a certified mechanic functionally checked the aircraft's brakes. He reported that the brakes functioned properly and that there was no evidence of a mechanical failure. Further inspection of the aircraft by the pilot's mechanic revealed that the left brake torque plate and brake cylinder were cracked. Corrosion was noted to the right wheel and brake cylinder assemblies. The right brake disc was pitted and worn to limits (Inspection report attached).