On April 11, 2007, approximately 1430 mountain daylight time, a Cessna 170A, N1258D, piloted by an airline transport-certificated pilot, was substantially damaged when the right brake failed and the airplane veered to the right and departed runway 35 at Front Range Airport (FTG) Watkins, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot was not injured. The local flight originated approximately 1340. The pilot had been practicing touch-and-go landings. On his final landing, the airplane swerved to the right and the right wing struck the ground, bending the spar. The airplane then departed the runway. According to the FAA airworthiness inspector who examined the airplane, the right brake caliper assembly showed "severely worn shoes with uneven wear." The inspector surmised that when the pilot applied the brakes, the uneven brake shoe wear "caused the caliper pins to engage misaligned, contacting the rotor, locking and shearing the caliper assembly."