(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
[DOC] [TLE] E-3 Sentry (AWACS) > U.S. Air Force > Fact Sheet Display [PAR] Sep 22, 2015 ... MissionThe E-3 Sentry is an airborne warning and control system, ... modified 
Boeing 707/320 commercial airframe with a rotating radar dome.