On Tuesday afternoon, October 5, 1993, at 1340 Pacific daylight time, a Cessna 172RG, N16ED, operated by Avia Flight Services, impacted the runway while landing at the Corvallis Municipal Airport, Corvallis, Oregon. There was no flight plan filed for the local training flight, which took off at 1225. The flight was conducted under 14 CFR 91 in visual meteorological conditions. The certified flight instructor and the commercial pilot were not injured in the accident. The aircraft was substantially damaged. There was no fire. Flight instructor Anderson reported that he pulled the landing gear circuit breaker to deactivate the warning horn while he was conducting training for commercial pilot Foster. He said that after finishing several training maneuvers, he reduced the throttle while over the airport to simulate an engine failure, and the commercial pilot initiated a forced landing to the runway. The landing gear handle was placed in the down position, but the gear did not fully extend. Just as the aircraft was touching down on the runway, the CFI noticed that the gear was not fully down, but there was not sufficient time for remedial action. The aircraft then impacted on the runway with the gear partially extended.