The pilot of the experimental amateur-built airplane was performing a simulated forced landing to the airport runway. As the airplane was in the landing flare, another pilot radioed that the accident airplane's landing gear was still retracted. About that time, the aft mounted propeller struck the runway and the pilot increased power in an attempt to abort the landing. The pilot subsequently lost control of the airplane and it impacted terrain to the side of the runway, resulting in serious injuries to the pilot and flight instructor, and substantial damage to the airframe. Examination of the wreckage following the accident revealed that the landing gear switch was selected to the "UP" position.