Phantom IIs and sometimes Vought F-8 Crusaders escorted the American bombers such as Boeing B-52 Stratofortresses, Republic F-105 Thunderchiefs and Douglas A-4 Skyhawks. In some cases the missions of F-4 were "mixed", when some F-4 were equipped with bombs, and some F-4 acted as escorts (similar cases occurred with F-8). Modern era The advent of the air superiority fighter, such as the McDonnell Douglas F-15 Eagle, meant that high value assets like tankers, airborne early warning and control, command platforms, bombers and attack aircraft would be protected by air superiority fighters, sometimes flying far afield and ahead of them, engaging distant enemy air units, rather than by direct escorts staying in sight nearby. The development of the multirole fighter, such as McDonnell Douglas F/A-18 Hornet, also decreased the need for escorts, as the aircraft on air strike mission became capable of effectively defending themselves. During the 2010s, the US Air Force was in the early stages of developing a new fighter intended to operate as an escort for the next generation Northrop Grumman B-21 Raider strategic bomber. Notes References Citations Bibliography Bergstrom, Christer & Dikov, Andrey & Aptipov, Vladislav. Black Cross – Red Star, Air War over the Eastern Front. Volume 3. Everything for Stalingrad. Eagle Editions Limited, 2006. . Bodie, Warren M. The Lockheed P-38 Lightning: The Definitive Story of Lockheed's P-38 Fighter. Hayesville, North Carolina: Widewing Publications, 2001 [1991]. . Bowman, Martin W. B-17 Flying Fortress Units of the Eighth Air Force, Volume 2. Oxford, UK: Osprey Publishing, 2002. . Boylan, Bernard. Development of the Long Range Escort Fighter. Washington, D.C: USAF Historical Division, Research Studies Institute, Air University, 1955. Retrieved: 15 July 2014. Cole, Christopher and Cheesman, E. F. The Air Defence of Great Britain 1914–1918. London: Putnam, 1984. . Freeman, Roger A. B-17 Fortress at War. New York: Charles Scribner's Sons, 1977. . Fredette, Raymond H. The Sky on Fire: The First Battle of Britain 1917–1918. New York: Harvest, 1976. . Gunston, Bill. "Parasitic Protectors." Aeroplane Monthly, Volume 3, No. 10, October 1975. Jenkins, Dennis R. F/A-18 Hornet: A Navy Success Story. New York: McGraw-Hill, 2000. . Lesnitchenko, Vladimir. "Combat Composites: Soviet Use of 'Mother-Ships' to Carry Fighters, 1931–1941." Air Enthusiast, No. 84, November/December 1999. Levine, Alan J. The Strategic Bombing of Germany, 1940–1945. Westport, Connecticut: Praeger, 1992. . McLaren, David. Republic F-84 Thunderjet, Thunderstreak & Thunderflash: A Photo Chronicle. Atglen, Pennsylvania: Schiffer Military/Aviation History, 1998.