World War II Antisubmarine and Alaskan service The first predecessor of the
squadron was activated at
March Field, California in January 1941 as the
21st Bombardment Squadron (Heavy), one of the original squadrons of the
30th Bombardment Group. The 21st was equipped with a mix of
Douglas B-18 Bolo,
Boeing YB-17 Flying Fortress, and
Lockheed A-29 Hudson aircraft. In May, the squadron moved to
New Orleans Airport, where it continued training as a bomber unit. When
the Japanese attacked Pearl Harbor, the squadron began
antisubmarine patrols over the Gulf of Mexico and dispatched a detachment to
Savannah Army Air Base, Georgia to hunt for
U-boats off the Atlantic Coast. By the end of the month, though, the squadron was patrolling the Pacific Coast with its Hudsons, the 30th Group having returned to March Field after a brief stay at
Muroc Army Air Field, California. From May through June 1942, the squadron operated through detachments at
McChord Field, Washington and
Hamilton Field as well as at civilian airports in Southern California. Although the squadron spent fifteen months operating under the control of the 28th Group in Alaska, it remained formally assigned to the 30th Group at March Field. By September 1943, when the
Aleutian Campaign had ended and the squadron was released to return to the United States, the 30th Group and its remaining squadrons had departed for the Pacific, and the squadron was disbanded at
Smoky Hill Army Air Field, Kansas on 1 November.
Strategic bombing of Japan The second predecessor of the squadron was the
21st Bombardment Squadron, Very Heavy, which was activated at
Dalhart Army Air Field, Texas as one of the original four squadrons of the
16th Bombardment Group. However, before the squadron could be manned or equipped, groups flying the
Boeing B-29 Superfortress were reorganized from four bombardment squadrons with seven aircraft each to three bombardment squadrons with ten aircraft each and the squadron was inactivated on 10 May 1944. The squadron's inactivation lasted only three weeks, however, and on 1 June it was again activated at Dalhart, this time as a component of the
501st Bombardment Group. In August, the squadron moved to
Harvard Army Air Field, Nebraska, where it trained for combat with the Superfortress. It left Harvard in March 1945 after completing its training and arrived at its combat station,
Northwest Field, Guam, on 14 April. The squadron flew its first combat mission against
Truk Island on 19 June, and eight days later made its first attack on Japan. The unit's missions focused on Japan's petroleum facilities on
Honshu. In July 1945, it received a
Distinguished Unit Citation for attacks on the
Maruzen oil refinery at Shimotso, the Utsobo oil refinery at
Yokkaichi and storage facilities at
Kawasaki. After
VJ Day, the squadron dropped food and supplies to
prisoners of war in Japan, China, Korea and Manchuria. The squadron remained on Guam until it was inactivated in June 1946. It initially flew
Cessna O-1 Bird Dog aircraft in the forward air control mission. However, it was not until August that the squadron became operational. The 21st operated primarily in the
II Corps Area, with its aircraft dispersed to support
United States Army,
ARVN and Korean units. While initially organizing, it directed air strikes during the
Battle of Duc Co The squadron performed visual reconnaissance with light aircraft, flying slowly at low altitude. By patrolling the same area regularly, squadron forward air controllers grew familiar with the terrain and learned to detect changes that could indicate enemy forces hiding below. The controller called in
fighter-bombers and marked targets with smoke grenades or white phosphorus rockets. After the attacks, controllers flew low over the target to assess the damage. On 27 February 1967, Captain
Hilliard A. Wilbanks, one of the squadron's forward air controllers, was flying visual reconnaissance in his Cessna O-1 ahead of a
South Vietnamese ranger battalion. He located a well-concealed numerically superior
Viet Cong (VC) force poised to ambush the rangers. The enemy immediately fired on his plane and advanced on the ranger force, which was pinned down by devastating fire. Capt. Wilbanks recognized that
close air support would not be able to arrive soon enough to help the rangers to withstand the advancing enemy. Flying through withering fire at treetop level, he flew over the VC and inflicted many casualties by firing his rifle out the side window of his Bird Dog. Despite increasingly intense antiaircraft fire, he made repeated low passes over the VC. His tactics interrupted the VC's advance and allowed the rangers to withdraw to safety. During his final attack, Capt. Wilbanks was mortally wounded and his aircraft crashed between the opposing forces. He saved numerous friendly personnel from certain injury or death. For his action that day, he was awarded the
Medal of Honor. The single engine of the O-1 Bird Dog made it particularly vulnerable to ground fire and it lacked radio equipment that would permit it to communicate with ground troops and attacking aircraft at the same time. Its low speed and endurance, in addition to making it more vulnerable, sometimes delayed its arrival in areas of operation and the time it could operate. In 1968, the squadron began equipping with twin engined, faster
Cessna O-2 Skymasters that had higher speed, greater endurance and better communications equipment, although the O-1 would not be completely phased out of squadron operations until 1971. The 21st moved to
Cam Ranh Bay Air Base, South Vietnam in September 1969, and to
Phan Rang Air Base two years later. As the United States withdrew forces from Vietnam, the squadron moved to
Tan Son Nhut Air Base in January 1972 and was inactivated there on 21 February 1973.
Cold War The squadron was again activated at
MacDill Air Force Base, Florida, at the end of August 1973. At MacDill, it was equipped with the
Cessna OT-37 Tweet and was assigned to the
68th Tactical Air Support Group, which was located at
Shaw Air Force Base, South Carolina. Little less than a year later, on 1 July 1974, it moved to Shaw, where it joined its parent
507th Tactical Air Control Group, which assumed the mission of the 68th Group when the 68th was inactivated in June 1974. At Shaw, the squadron converted from the OT-37 to the OV-10 Bronco in 1988. It re-equipped with the
Fairchild Republic OA-10 Thunderbolt II in 1991, shortly before being inactivated and transferring its mission, equipment and personnel to the
21st Tactical Fighter Squadron in November 1991.
Testing, evaluation and analysis The squadron was redesignated the
21st Test and Evaluation Squadron and activated on 15 September 1992 at
Randolph Air Force Base, where it was assigned to the
12th Operations Group. It absorbed the resources of the 3307th Test and Evaluation Squadron, which had been activated on 15 September 1991 and assigned to the 3300th Training Support Group, and which was simultaneously inactivated. Air Training Command (ATC) had established the 3307th Squadron to perform tests and evaluations of new ATC systems including
aircraft,
simulators and
software to determine if these acquisitions met operational requirements. The squadron became the
Air Education and Training Command Studies and Analysis Flight at the end of March 1994. In April 1997, it added the resources of the 602d Training Support Squadron at Edwards Air Force Base, California, which developed training programs for new
weapons systems as they were acquired by the Air Force and became a squadron again. Personnel at Edwards formed Detachment 1 of the squadron. The Edwards detachment later downgraded to Operating Location A in 2003, and its mission and personnel were absorbed by the squadron at Randolph in 2008. The squadron currently includes a technology innovation flight and a strategy analysis flight. ==Lineage==