On September 7, 1997 approximately 1045 Pacific daylight time, a Curtis-Wright Travel Air 12-Q, N496W, ground-looped during the landing roll at Eastern Oregon Regional Airport, Pendleton, Oregon. The commercial pilot, who was the sole occupant, was not injured, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Baker, Oregon about one hour earlier, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, he performed a wheel landing, during which everything appeared normal, and then lowered the tail wheel to the runway. As soon as the tail wheel touched down, the aircraft started to swerve to the left, and the pilot's input of right rudder did not seem to make any difference. Although the pilot applied almost full right rudder, the aircraft ground-looped to the left, and one of the wings impacted the ground. Immediately after the accident, the pilot and a mechanic inspected the aircraft, and discovered that one of the springs that ran from the rudder to the tail wheel mechanism had become disconnected. It was the pilot's opinion that the spring had come loose while he was taking off from a rough turf runway at his last point of departure.