The C-21 is a twin turbofan-engine aircraft used for cargo and passenger airlift. The aircraft is the military version of the Lear Jet 35A business jet. In addition to providing cargo and passenger airlift, the aircraft is capable of transporting one litter or five ambulatory patients during aeromedical evacuations. Assigned Units: 375th Airlift Wing / Scott AFB, Illinois; National Guard Bureau / Peterson AFB, Colorado; Air Force Flight Standards Agency / Joint Base Andrews, Maryland; Air Education and Training Command / Keesler AFB, Mississippi