On June 17, 2019, about 1630 eastern daylight time, a Taylorcraft BC12, N43766, was substantially damaged when it was involved in an accident at Solberg-Hunterdon Airport N51, Readington, New Jersey. The pilot was not injured. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. The pilot reported that he departed N51 and performed some "air work" before returning to the airport for practice landings on runway 13 in the tailwheel-equipped airplane. Runway 13 was a mowed, turf runway, which was 3,444 feet long and 200 feet wide. The pilot performed two landings to runway 13 and completed a traffic pattern to perform a third landing. During the third approach, instead of aligning with the runway, the airplane touched down about 80 feet left of the mowed surface in dense grass that was between 3-4 feet tall. The ground track revealed the airplane travelled about 80 feet before it nosed over, came to rest inverted, and substantially damaged the rudder. In a telephone interview with a Federal Aviation Administration (FAA) inspector, the pilot stated that the brakes "locked," which caused the nose-over event. He stated that he was not aware of the height and thickness of the grass, as he believed he had landed on the runway. The pilot added that the landing surface was not a factor and insisted that the airplane's brakes had locked.Not necessary to support analysis and PC, and data contained within the data blocks. FAA inspectors examined the airplane at the accident site and later tested the brakes on the airplane after its recovery. With the brakes applied, the left-side braking action was "weak," and the right side had no braking action. When asked if it was possible to lock the brakes, the airworthiness inspector said, "Not at all." He added that with the brakes fully applied in the cockpit and when pushed by hand at the tail, the airplane rolled on both main landing gear tires with little to no resistance.