Incident Overview
The pilot reported that during descent in the airport traffic pattern, another airplane announced its position nearby. The pilot diverted attention to locate the traffic visually. The traffic collision avoidance system (TCAS) annunciated in proximity to the other airplane. After passing the traffic, the pilot initiated the turn to base leg. During base and final legs, the gear warning horn sounded, but the pilot stated he mistook it for the TCAS alert. The pilot subsequently landed with the landing gear retracted.
Damage and Inspection
The airplane sustained substantial damage to the fuselage supporting structure. Following the accident, the aircraft was placed on jacks, and the landing gear was extended using the airplane's own systems. No abnormal operation was indicated during this test.
Pilot Report
The pilot reported wearing noise-cancelling headphones during the flight but stated he was able to hear the gear warning horn annunciate. The pilot also reported no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.