On April 12, 1995, at 1625 hours mountain standard time, an amateur built Covington Lancair 320, N24KB, landed hard and collapsed the main landing gears on runway 11 at Ernest J. Love Field, Prescott, Arizona. The pilot was completing a local visual flight rules personal flight. The airplane, registered to and operated by the pilot, sustained substantial damage. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at Ernest J. Love Field at 1550 hours. The pilot said in a telephone interview conducted on April 12, 1995, that while on final approach, the throttle "continually crept toward the idle position." This condition required him to hold the throttle in with his right hand and manipulate the control stick with his left hand. The pilot said he was unable to maintain a stabilized approach and the airplane began porpoising up and down. He said that he failed to execute a go-around in a timely manner. During the go-around, the airplane settled to the ground and landed hard. Both main landing gears collapsed on touchdown. However, in the National Transportation Safety Board Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2, he said that he was conducting a test flight following a new weight and balance configuration. He said the airplane had not been flown for 7 months. After takeoff, he circled the airport between 15 and 20 minutes checking engine performance and temperatures and then entered the traffic pattern. On the first approach, the airplane pitched violently about the lateral axis and he "over controlled" the airplane. He was not used to handling the control stick with his left hand and that he had " . . . too much back trim set in . . . ." He then executed a go-around and reentered the traffic pattern. He said the second attempt to land was " . . . even worse than the first, ending in a stall and impact with the runway . . . ." After the accident, he said he realized that the elevator trim was set for a nose-heavy condition--the previous condition of the airplane. The pilot also noted in the accident report that the airplane did not experience any preimpact mechanical malfunctions or failures.