(Jimmy of the Clue Crew reports from Kadena Air Base in Japan.) The 30-foot rotating dome on top of the AWACS E-3 is a highly advanced version of this system first implemented in England in the 1930s
The dome is 30 
feet in diameter, 6 feet thick and is held 11 feet above .... Pacific Air Forces has 
four E-3 Sentries at Kadena AB, Japan and Elmendorf AFB, Alaska.