Beechcraft C - 12 Huron The C - 12 Huron is the military designation for a series of twin - engine turboprop aircraft based on the Beechcraft Super King Air and Beechcraft 1900 . C - 12 variants are used by the United States Air Force , United States Army , United States Navy and United States Marine Corps . These aircraft are used for various duties , including embassy support , medical evacuation , as well as passenger and light cargo transport . Some aircraft are modified with surveillance systems for various missions , including the Cefly Lancer , Guardrail and Project Liberty programs . Design and development . The first C - 12A models entered service with the U . S . Army in 1974 and was used as a liaison and general personnel transport . The aircraft was essentially an " off - the - shelf " Super King Air 200 , powered by the type ' s standard Pratt & Whitney Canada PT6 A - 41 engines . The U . S . Navy followed suit in 1979 , ordering a version of the Super King Air A200C ( modified with a 52 inch by 52 inch cargo door from the Super King Air 200C ) , designating it the UC - 12B , for logistics support between Naval and Marine Corps air stations , air facilities , and other activities , both in CONUS and overseas . The cabin can readily accommodate cargo , passengers or both . It is also equipped to accept litter patients in medical evacuation missions . Through 1982 , the Navy ordered 64 of these aircraft . A U . S . Air Force variant of the plane for surveillance roles primarily over Afghanistan and Iraq is the MC - 12 Liberty . For that variant , Beechcraft builds the basic plane and then sends it to Greenville , Texas where sophisticated Intelligence , Surveillance & Reconnaissance equipment is installed by L - 3 Communications Missions Integration . As of 2013 the Liberty program has exceeded 300 , 000 combat flying hours . C - 12J . To meet the needs of transporting larger groups , the U . S . Army purchased six C - 12J aircraft , based on the Beechcraft 1900 C commuter airliner . One of the military C - 12Js is used for GPS jamming tests at the 586th Flight Test Squadron , Holloman Air Force Base , New Mexico . Another is based at the 517th Airlift Squadron , Elmendorf Air Force Base , Alaska . Three were based at the 55th Airlift Flight , Osan Air Base , South Korea . They have been relocated to the 459th Airlift Squadron , Yokota Air Base , Japan . The remaining two are used by U . S . Army Aviation . Although the UD - series 1900s were manufactured exclusively for military use , the United States military and other military and government organizations use 1900s from other series such as the UB - series 1900C , and 1900Ds which may be found elsewhere . The Air Force currently operates only 4 C - 12Js . 3 are operated by the 459th Airlift Squadron at Yokota Air Base , Japan and 1 by the Air Force Materiel Command from Holloman AFB , New Mexico . The Army has 2 C - 12Js in use , 1 in Korea and 1 in Germany . Variants . Beechcraft 1900 - based variant . " Note : The U . S . military also operates other King Air versions under other designations , including the C - 6 Ute and T - 44 series . In addition , there are a number of Beechcraft 1900s operated by the military under civilian registrations , using their civilian model designations . "