Accident Sequence
The flight instructor reported that during a training flight, the pilot under instruction was practicing a simulated single engine failure approach. On the second approach, the student reduced the left engine power setting to 12 inches of manifold pressure, which activated the landing gear auditory warning horn. While on downwind, the student performed prelanding checks and asked the instructor whether to deploy the landing gear. Because the student was struggling to maintain altitude, the instructor instructed the student to delay landing gear deployment until the final landing checks.
Shortly after turning final, the student performed the final landing checks and provided verbal cues of completion but did not include the landing gear check. The instructor stated that he was distracted and focused on corrections because the student was struggling to maintain altitude and the runway centerline during the final approach. As a result, the instructor did not verify that the landing gear was extended.
During the landing flare, the instructor realized the landing gear was not extended and immediately took control of the airplane. He leveled the airplane and landed on the runway with the gear retracted.
Damage
The airplane sustained substantial damage to both engines. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.