The Douglas DC-9 entered service Dec. 8, 1965, and was produced until 1982. More than 976 DC-9s were built -- including 47 C-9 versions for military customers. The 90-passenger DC-9-10 was expanded into the 15-foot longer DC-9-30, which could carry up to 115 passengers. The DC-9-20, was especially useful for short landing fields. The DC-9-40 was 6 feet longer than the -30 and could hold 125 passengers, and the DC-9-50, was 12 feet longer and had the "new-look" interior patterned after the wide-cabin DC-10. The DC-9-80, later redesignated MD-80, launched the family of commercial jet airliners with McDonnell Douglas "MD" designation.