This 1971 reference page from the 366th Tactical Fighter Wing's 'DaNang Inflight Aid' manual defines the North Vietnam border and Positive Control Area boundary in radial-and-distance format relative to regional TACAN stations, critical data for F-4 Phantom crews operating near contested airspace. The accompanying frequency list for out-country control agencies, including the airborne command posts known as Hillsboro/Moonbeam and Cricket/Alleycat, reflects the extensive air traffic coordination required for combat operations over Laos and North Vietnam during the war. Project: 218454