NTSB Factual Report

The pilot stated that after the airplane crossed the runway threshold, he reduced engine power to idle and the gear warning horn sounded. The pilot reported that he misinterpreted the gear warning horn for the ground proximity warning system and the airplane landed with the gear retracted. The airplane sustained substantial damage to the spar carry-through structure and left spar attachment. The pilot reported no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

NTSB Probable Cause

The pilot's failure to extend the landing gear before landing.