This was the most advanced F-105 but R. Strange McNamara shut down the F-105 prod. line so he could force the F-111 on the Air Force.
It could fly blind.
Experience in Vietnam demonstrated the need for a better visual and blind bombing capability. In March 1968, the Air Force ordered development of an upgraded bombing/navigation system, incorporating a Singer-General Precision inertial navigation system, improvements to the AN/APN-131 navigation radar, and solid-state circuitry for the R-14A radar, which was redesignated R-14K. Furthermore, the digital AN/ARN-92 long-range navigation receiver replaced the problematic AN/ARN-85 receiver. The additional avionics were housed in a long, raised dorsal spine. The modified bombing/navigation system was known as Thunderstick II. F-105s with this system could achieve a bombing circular error of probability (CEP) of 50 feet (15 m) from an altitude of 15,000 ft (4,600 m). Although the first Thunderstick II aircraft flew in 1969, they were not used in Vietnam. A total of 30 F-105Ds received this modification.