On September 11, 2012, about 1500 Pacific daylight time, a Hawker MK11 Sea Fury, N4434P, was substantially damaged when the right main landing gear collapsed during landing roll at the Reno Stead Airport (RTS), Reno, Nevada. The airplane was registered to Air Zurich LLC, Lake Zurich, Illinois, and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as Race 15. The commercial pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the air race flight. The local flight originated from RTS about 30 minutes prior to the time of the accident. In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that following an uneventful takeoff, he had a malfunction with retracting the landing gear. After several attempts, the landing gear retracted, and he performed his race course qualifying lap. Upon exiting the closed race course, he attempted to extend the landing gear. After about 20 minutes of troubleshooting the landing gear, it appeared to be down, however, with the right main landing gear warning light illuminated. The pilot initiated a precautionary landing on runway 14. During the landing roll, the right main landing gear collapsed and the airplane exited the right side of the runway. Subsequently, the airplane came to rest upright adjacent to the runway. Examination of the airplane by the NTSB IIC revealed that the right wing, right aileron, and rudder were damaged. Further examination of the recovered airplane by a representative from Sanders Aeronautics, Ione, California, revealed that the landing gear rotary selector valve seal had failed, which allowed landing gear hydraulic pressure to bypass. The representative stated that the bypass in hydraulic pressure would preclude the landing gear retraction system from operating normally.