On March 19, 2000, at 1945 hours mountain standard time, a Piper PA-31-T1, N5WC, landed gear up at the Scottsdale, Arizona, airport. The airplane, operated by Gunslinger Investment Corporation, Telluride, Colorado, sustained substantial damage. The airline transport pilot and passenger were not injured. The personal cross-country flight had originated in Telluride, Colorado, at 1815, and was terminating at the time of the accident. Visual meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed. The pilot reported that while landing on runway 21, he felt the rudder pedals vibrating. The airplane settled and he heard the propellers striking the runway. The airplane veered to the right off the runway centerline and struck a runway light. The pressure bulkhead was punctured and there was damage to the right engine air scoop cowling, the right wing leading edge, the flaps, gear doors, bottom antennas, pitot tube, and right spinner. A Federal Aviation Administration inspector from the Scottsdale Flight Standards District Office responded to the site. He reported that on March 23, 2000, he witnessed the landing gear being swung at the Scottsdale airport. He stated that no discrepancies were noted during the test. The landing gear light and horn systems functioned normally.