What happened
The pilot reported that he was conducting a normal approach to Runway 18. Upon reaching the threshold, he maintained an airspeed between 70 and 80 mph. After the main wheels touched down on the runway surface, the pilot applied the hand brake to assist in slowing the aircraft.
Shortly after brake application, the aircraft began to yaw sharply to the right. The pilot described the event as feeling like the right brake had grabbed hard unexpectedly. This sudden braking action caused the aircraft to spin approximately 45 degrees off its original heading. The plane continued to skid laterally across the pavement until it departed the runway surface.
The excursion ended when the aircraft struck a Visual Approach Slope Indicator (VASI) installation located near the runway edge. Following the impact, the aircraft came to a complete stop approximately 25 feet from the active runway pavement.