On April 30, 2010, about 1630 local time, a Cessna 172N, N733SN, registered to Micronesian Aviation Systems Inc., and operated by a private pilot, had the propeller strike the pilot while the airplane was being prepared for a 14 Code of Federal Regulations (CFR) Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The private pilot received serious injuries, and the safety pilot in the airplane and occupying the right front seat was not injured. The airplane, which was being prepared to be flown when the accident occurred, was not damaged. In a statement submitted to the Safety Board investigator-in-charge (IIC), the safety pilot reported that during the starting sequence the pilot was unable to start the engine. The safety pilot stated that after attempting two more start attempts the pilot said that he would exit the airplane and rotate the propeller [by hand] to see if that would “help out with the engine start.” The safety pilot further reported that prior to exiting the airplane the pilot pulled the mixture to the cutoff position, pulled the throttle to idle, turned off the master switch, and turned the magnetos off and pulled out the keys. The safety pilot reported that the pilot then exited the airplane and proceeded to the propeller where “…he turned the propeller a few times with one hand, and then with both hands. As he turned the propeller with both hands his head went beneath the propeller and [it] struck his head.” The safety pilot added that emergency medical personnel responded to the injured pilot a short time later and transported him to a local hospital for treatment.