In 1955 by Republic in the USA a heavy fighter-bomber was developed, capabale of carrying a heavy bomb load at low altitudes - the F-105 Thunderchief. The needs of the US Air Force made a two seater version necessary, designated F-105F. During the Vietnam war special aircraft were needed to fight the North Vietnamese missile sites and their guidance radars. The US Air Force reacted by using the available aircraft and updating them with search electronics to detect and attack SAM sites in a program called "Wild Weasel". The F-105F was equiped with state of the art electronics, carried mostly on outboard stations under the wing. It was designated EF-105F. Attacking enemy missile sites meant using a special missile, the AGM-45 Shrike that guided itself into the radar site by riding the enemy radar beam. Since the electronics were carried under the wing, the usefull load was limited and therefore the equipment was housed in semi-cicular pods on both sides of the fuselage, giving the F-105G version its typical appearance.
Top speed was Mach 2.15 at 11.600 m; range 3.330 km.