RAF Harrowbeer was a WWII Fighter Station that was built on land at Yelverton. It opened on the 15th August 1941 and was closed for the first time on 31st July 1945. It was then reopened and remained in RAF Use until the late 50s.
The RAF Harrowbeer Interest Group website has full information on the history of the airfield here.
Application forms for next year's event will be available during October.