A Beechcraft B100, N66804, was substantially damaged when the right main landing gear collapsed during landing at the Jackson-McKellar-Sipes Regional Airport (MKL), Tennessee. The commercial pilot was not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the business flight that originated from Memphis International Airport (MEM), Tennessee. According to the pilot, he was flying businessmen to different airports all day and was returning from MEM, to his home airport. The flight was uneventful, and on the final approach leg into MKL, he verified that the three green landing gear indicator lights were illuminated, and all instruments were indicating normal. He further stated that the airplane landed “firmly” and the right wing dropped down far enough that the right engine propeller blades contacted the runway. The pilot then pulled back on the controls and the airplane became airborne again for a short time before settling back down on the runway. The right main landing gear collapsed. The airplane then veered off the right side of the runway, struck a runway sign, and contacted a weather antenna. Examination of the wreckage by a Federal Aviation Administration inspector revealed that the airplane was resting on its right wing, against the airport’s weather service antenna. The right landing gear was inside the wheel well. The left engine was hanging loose from the motor mounts. After the airplane was lifted up, the inspector noticed that the right main landing gear actuator was fractured in half. PROBABLE CAUSE: “The pilot’s improper landing flare, which resulted in a hard landing.”