431st Test and Evaluation Squadron The 431st Test and Evaluation Squadron is an inactive United States Air Force unit . Its last assignment was with the Tactical Air Command 57th Fighter Wing stationed at Nellis AFB , Nevada . It was inactivated on 30 June 1992 . History . World War II . Established by Fifth Air Force in Australia in May 1943 specifically to accommodate very long range Lockheed P - 38J Lightning s at Amberley Airfield in Queensland , Australia . The 431st was specifically trained to provide long - range escort for bombers during daylight raids on Japanese airfields and strongholds in the Netherlands East Indies and the Bismarck Archipelago . On 14 August 1943 , the 431st transferred from Amberley airfield to Port Moresby . New Guinea . Engaged in combat operations , providing escort for B - 25 Mitchell medium bombers that were engaged in strafing attacks on airdromes at Wewak but also destroyed a number of the enemy fighter planes that attacked the formation . Also intercepted and destroyed many Japanese aircraft which were sent against American shipping in Oro Bay on 15 and 17 October 1943 . Covered landings in New Guinea , New Britain , and the Schouten Islands . After moving to Biak in July 1944 , the squadron flew escort missions and fighter sweeps to the southern Philippines , Celebes , Halmahera , and Borneo . Moved to the Philippines in October 1944 and attacked enemy airfields and installations , escorting bombers , and engaging in aerial combat during the first stages of the Allied campaign to recover the Philippines , October – December 1944 . The squadron flew many missions to support ground forces on Luzon during the first part of 1945 . Also flew escort missions to Southeast China and attacked railways on Formosa . Began moving to Ie Shima near Okinawa in August 1945 but the war ended before the movement was completed . After active combat ended , on 22 September 1945 , the squadron moved to Seoul Airfield , Korea for occupation duty as part of the 308th Bomb Wing , assigned to the 315th Air Division of Far East Air Forces . The unit moved to Kimpo Airfield , on 7 January 1946 where the it converted to the very long - range P - 51H Mustang . The squadron was reassigned to Nagoya Airfield , Japan in March 1947 and later moved to Itazuke Airfield , Japan in August 1948 . It became a subordinate unit of 475th Fighter Wing on 10 August . The squadron was inactivated on 1 April 1949 at Ashiya Airfield , Japan . Cold War . Reactivated as part of Air Defense Command in November 1952 , replacing the federalized 172d Fighter - Interceptor Squadron of the Michigan Air National Guard . Assigned to Selfridge AFB , Michigan with mission of air defense of the Detroit / Akron area and Great Lakes initially flying the F - 86F Sabre s reassigned from the 63d Fighter - Interceptor Squadron at Oscoda AFB , Michigan . Relieved from duty with ADC and reassigned to USAFE under Seventeenth Air Force . Flying from Wheelus AB , Libya to provide air defense over the large North African base and expansive training ranges . Replaced its Korean War vintage F - 86F ' s with new F - 86D Sabre Interceptors in January 1955 . Moved to Zaragoza AB , Spain in September 1958 and was reassigned to the Strategic Air Command Sixteenth Air Force . Inactivated in 1964 with withdrawal of B - 47 Stratojet from inventory and SAC turning jurisdiction of its Spanish refueling bases to USAFE . Was reassigned to Tactical Air Command , being stationed at George AFB , California , assigned to 8th Tactical Fighter Wing . Equipped with F - 4C Phantom II tactical fighter - bomber , engaged in training , participated in numerous exercises , operational readiness inspections , deployments . Re - equipped with new F - 4D Phantom II in 1965 and reassigned to 479th Tactical Training Wing at George AFB . The F - 4D was an improved version of the F - 4C , which the 8th TFW had been deployed with to Southeast Asia . In February 1966 , the squadron began F - 4D replacement pilot training for personnel to be deployed to Southeast Asia . Along with the USAF fighter pilot training , the squadron began training foreign personnel in F - 4 operations and maintenance in March 1969 . Pilots were trained from Israel , Iran , Japan , and West Germany . Inactivated on 30 October 1970 due to budget reductions . Reactivated at George AFB in 1975 as part of the 35th Tactical Fighter Squadron . Engaged in F - 4E " Wild Weasel " training as a Tactical Fighter Training Squadron against F - 105G Thunderchief s . Inactivated due to budget cuts in 1978 . Fighter Weapons Squadron . Reactivated at McClellan AFB , California in 1980 as an F - 111 Aardvark evaluation squadron , assuming mission of Detachment 3 , 57th Fighter Weapons Wing , home stationed at Nellis AFB , Nevada , being a Geographically Separated Unit ( GSU ) of the 57th FWW . McClellan AFB was the Air Force Logistics Command prime support depot for the F - 111 and changes and modifications could be made there and tested by the detachment . The 431st ' s mission was to test and evaluate TCTO ( Time Change Technical Order ) modifications to the F - 111A / D / E and F models prior to those hanges being released to operational F - 111 Tactical wings in the United States and Europe . In addition was tasked with exploiting foreign technologies , and developing leading edge tactics to improve the future combat capability of aerospace forces . Squadron remained active until June 1992 when the F - 111 was retired at the end of the Cold War .