On May 12, 2015, at 0740 eastern daylight time, a Taylorcraft BC-12D, N43715, was substantially damaged while attempting to land at Inverness Airport (INF), Inverness, Florida. The private pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local, personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.The pilot performed a preflight inspection of the airplane before departing on the local flight with the intent of practicing touch-and-go landings. The first two practice landings were uneventful. The pilot landed the airplane in a "three point full stall" attitude during the third landing. During the landing roll, and just before the pilot intended to increase engine power to take off, he felt a vibration originating from the tailwheel that was increasing rapidly in intensity. The airplane then suddenly veered to the left. The pilot attempted to compensate by applying full rudder to the right, but the airplane continued left, departed the runway, and struck a taxiway sign. The airplane subsequently pitched forward and the nose struck the ground, resulting in substantial damage to the fuselage. A Federal Aviation Administration (FAA) inspector examined the airplane following the accident and noted the tailwheel steering linkage was disconnected from the rudder arm. The right side tailwheel spring, which attached the right side of the tailwheel steering arm to the rudder remained attached to the tailwheel. The left side spring was not attached and was recovered by the pilot from the runway. The associated hardware used to attach the spring to the rudder arm were not recovered. Review of the airplane's maintenance records revealed that the airplane's most recent annual inspection was completed on September 15, 2014. At that time the airframe had accrued 3,140 total hours of operation.