The pilot in a retractable landing gear-equipped airplane, accompanied by a company check-pilot, reported that they were conducting a training flight, in preparation for a 14 CFR Part 135 check ride.

During a no-flap landing exercise, as the airplane crossed the runway threshold, the airplane power was set to idle, and the aural warning sounded, which indicated that the landing gear was retracted. The airplane landed with the landing gear retracted.

The airplane sustained substantial damage to the lower fuselage.

The pilots reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.