requirements for CSOs, thus ensuring the continued viability of the CSO career path. Until its inactivation and closure in September 1993 due to Base Realignment and Closure (BRAC) action, all USAF undergraduate navigator training (UNT) took place with the former 323d Flying Training Wing at the former Mather AFB, California, utilizing the Boeing T-43A Bobcat and Cessna T-37 Tweet aircraft. In October 1993, training then shifted to the 12th Flying Training Wing at Randolph AFB, Texas, continuing at that location through 2009. Prior to its disestablishment at Randolph AFB, the 562d Flying Training Squadron of the 12th Flying Training Wing (12 FTW) was responsible for training inflight navigation with the Raytheon T-1A Jayhawk and Boeing T-43A Bobcat aircraft, while the 563d Flying Training Squadron taught electronic warfare in an academic and simulator environment. The 563d Flying Training Squadron also incorporated the T-43A Bobcat and the T-1A Jayhawk in advanced CSO training. The T-43A has since been retired and all T-1A CSO training aircraft transferred to the 479 FTG at NAS Pensacola. From 1994 until late 2009, a portion of USAF undergraduate navigator training took place at NAS Pensacola, integrated with the US Navy's student naval flight officer program under the aegis of Training Air Wing Six (TRAWING SIX) with USAF instructor navigators embedded in the wing and its squadrons. US Navy Training Squadron 4 (VT-4) and Training Squadron 10 (VT-10) conducted basic and intermediate flight training, initially the Raytheon T-34C Turbomentor until it was replaced by the T-6 Texan II, followed by training in the Raytheon T-1A Jayhawk and Rockwell T-39 Sabreliner. Training Squadron 86 (VT-86) then conducted advanced training in the T-39 and the Boeing T-45 Goshawk for student naval flight officers of the U.S. Navy, U.S. Marine Corps and numerous NATO/Allied and Coalition partner nations in addition to advanced USAF undergraduate navigator students destined for assignment as weapon systems officers in tactical aircraft. Prior to 2010, these USAF students destined for the F-15E Strike Eagle and the B-1B Lancer, as well as several USAF navigator flight instructors, were also fully integrated into these squadrons, with command of one squadron, VT-10, rotating between a USN commander who was a naval flight officer and a USAF lieutenant colonel who was a senior navigator or master navigator. Starting in the summer of 2010, following completion of initial flight screening, all US Air Force CSO students began attending training at NAS Pensacola