The 421st Fighter Squadron (421 FS) is part of the 388th Fighter Wing at Hill Air Force Base, Utah. It operates the Block 40 F-16 Fighting Falcon aircraft conducting air superiority missions. The squadron is one of the most decorated fighter squadrons in the United States Air Force, being awarded three Presidential Unit Citations and seven Air Force Outstanding Unit Awards for Valor in Combat.The unit was originally formed as the 421at Night Fighter Squadron in 1943.