The pilot of the tailwheel airplane departed an asphalt runway with the intention of moving the airplane to an adjacent turf runway at the same airport. The pilot stated that he made a normal takeoff, climbed above the trees, and began an approach to landing for the turf runway. The pilot made a "normal landing, and in an instant, the nose started down." The airplane's propeller struck the ground, and the airplane nosed over, coming to rest inverted. Post accident inspection by an FAA inspector revealed that the airplane exhibited no mechanical malfunctions or anomalies. The nearest weather reporting station, located approximately 9 nautical miles south of the accident site, reported winds from 060 degrees at 5 knots around the time of the accident. Several attempts were made to obtain the NTSB Pilot/Operator Report from the pilot and operator; however, neither submitted the form.