On July 15, 2010, about 1630 Pacific daylight time (PDT), a Beech A36, N4153Q, had a ground event when a passenger attempted to remove the wheel chocks and was struck by the propeller at McCarran International Airport, Las Vegas, Nevada. Connelly Equipment Rental Co. LLC, was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot was not injured, but the passenger sustained serious injuries. The airplane was not damaged. The cross-country personal flight had a planned destination of San Diego, California. The passenger stated that when the pilot and she arrived at the airplane they loaded the luggage and got into the airplane. The pilot attempted to start the engine, but it had difficulty starting, which she described as running rough and "putting." When the airplane finally started, the pilot attempted to move the airplane; however, the wheel chocks were still securing it. The passenger further stated she did not remember exactly what was said, but she did remember offering to help and he asked "would you mind hopping out and getting the chocks from the wheels." She stated that as she exited the airplane she did not receive any instruction and crawled under the right wing forward to the right side of the nose of the airplane. When she leaned in to remove the chocks the propeller struck her. During a telephone conversation, a Federal Aviation Administration inspector explained to the passenger the process associated with a preflight inspection and asked if the pilot had conducted one. The passenger stated that she did not recall him ever conducting a preflight on the airplane and that he usually just places the luggage in the airplane and goes. The pilot reported that after he realized that the chocks were still securing the airplane he did not want to shut down the engine because he did not believe it would start again due to the high outside air temperature. The pilot further stated that the van driver, who drove the pilot and passenger from the parking lot to the airplane, did not assist with loading the luggage or removing the wheel chocks as usual. The van driver reported that she did not remove the wheel chocks prior to leaving the pilot and passenger because the passenger stated that they were not ready. In the recommendation section of the NTSB 6120.1 pilot/operator form, the pilot stated that the accident could have been prevented by not allowing the passenger to exit the airplane while the engine was running.