The Century Series is a popular name for a group of US fighter aircraft representing models designated between F-100 and F-106 which went into full production. They included the first successful supersonic aircraft designs in the United States Air Force's service, which remained in active service well into the 1970s and 1980s with the Air Force Reserve and Air National Guard. Three later variants, the QF-100, QF-102 and QF-106, also continued in service, primarily as aerial target drones, until the late 1990s.