On June 7, 2001, about 1140 hours Pacific daylight time, a Gates Learjet LR-24A, N805NA, made a hard landing at Southern California Logistics Airport, Victorville, California. The National Aeronautics and Space Administration (NASA) was operating the airplane as a public-use flight. The airline transport pilot captain, copilot, and one passenger were not injured; the airplane sustained substantial damage. The local training flight departed Edwards Air Force Base, California, about 1055. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot submitted a written statement outlining the following history of flight. After completing local air work, the flight proceeded to Victorville to practice touch-and-go landings. The pilot made the first touch-and-go. The copilot successfully made the second touch-and-go. The copilot attempted the third touch-and-go. At 50 feet, he disengaged the yaw damper and entered a pilot induced lateral oscillation. The airplane rapidly decelerated and developed a high sink rate. The airplane dragged the right wing tip fuel tank, which separated from the airplane, and the airplane bounced back into the air. The airplane landed hard, the main landing gear collapsed, and the airplane skidded to a stop off the right side of the runway. Both pilots and the passenger deplaned through the main entry door. The pilot-in-command stated that he had not demonstrated the handling characteristics of the airplane with the yaw damper off. He felt he did not react quickly enough to prevent the accident.