On August 15, 1997, approximately 1130 Pacific daylight time, a Rotz RAF 2000 GTX SE homebuilt gyroplane, N9155H, was substantially damaged when it collided with the ground during takeoff from the Olympia airport at Olympia, WA. The sole occupant received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed for the 14 CFR 91 flight. The pilot reported that he had been cleared to takeoff from runway 17 and was starting a prerotation when the controller advised there was a LearJet on final and he would need to expedite his takeoff or clear the runway. The pilot initiated the takeoff roll with a rotor speed of 150 RPM. At 180 to 200 RPM the pilot disengaged the rotor and went to full power. As the aircraft became airborne, it started a roll to the left at about 10 ft elevation and the rotor blades struck the ground.