De Havilland Canada DHC - 4 Caribou The de Havilland Canada DHC - 4 Caribou ( designated by the United States military as the CV - 2 and later C - 7 Caribou ) is a Canadian - designed and produced specialized cargo aircraft with short takeoff and landing ( STOL ) capability . The Caribou was first flown in 1958 and although mainly retired from military operations , is still in use in small numbers as a rugged " bush " aircraft . Design and development . The de Havilland Canada company ' s third STOL design was a big step up in size compared to its earlier DHC Beaver and DHC Otter , and was the first DHC design powered by two engines . The Caribou , however , was similar in concept in that it was designed as a rugged STOL utility aircraft . The Caribou was primarily a military tactical transport that in commercial service found itself a small niche in cargo hauling . The United States Army ordered 173 in 1959 and took delivery in 1961 under the designation AC - 1 , which was changed to CV - 2 Caribou in 1962 . The majority of Caribou production was destined for military operators , but the type ' s ruggedness and excellent STOL capabilities requiring runway lengths of only 1200 feet ( 365 metres ) also appealed to some commercial users . U . S . certification was awarded on 23 December 1960 . Ansett - MAL , which operated a single example in the New Guinea highlands , and AMOCO Ecuador were early customers , as was Air America , ( a CIA front in South East Asia during the Vietnam War era for covert operations ) . Other civil Caribou aircraft entered commercial service after being retired from their military users . Today only a handful are in civil use . Operational history . In response to a U . S . Army requirement for a tactical airlifter to supply the battlefront with troops and supplies and evacuate casualties on the return journey , de Havilland Canada designed the DHC - 4 . With assistance from Canada ' s Department of Defence Production , DHC built a prototype demonstrator that flew for the first time on 30 July 1958 . Impressed with the DHC4 ' s STOL capabilities and potential , the U . S . Army ordered five for evaluation as YAC - 1s and went on to become the largest Caribou operator . The AC - 1 designation was changed in 1962 to CV - 2 , and then C - 7 when the U . S . Army ' s CV - 2s were transferred to the U . S . Air Force in 1967 . U . S . and Australian Caribous saw extensive service during the Vietnam War . The U . S . Army purchased 159 of the aircraft and they served their purpose well as a tactical transport during the Vietnam War , where larger cargo aircraft such as the Fairchild C - 123 Provider and the Lockheed C - 130 Hercules could not land on the shorter landing strips . The aircraft could carry 32 troops or two Jeep s or similar light vehicles . The rear loading ramp could also be used for parachute dropping ( also , see Air America ) . Under the Johnson - McConnell agreement of 1966 , the Army relinquished the fixed wing Caribou to the United States Air Force in exchange for an end to restrictions on Army rotary wing operations . On 1 January 1967 , the 17th , 57th , 61st , 92nd , 134th , and 135th Aviation Companies of the U . S . Army were inactivated and their aircraft transferred respectively to the newly activated 537th , 535th , 536th , 459th , 457th , and 458th Troop Carrier Squadrons of the USAF . On 1 August 1967 the " troop carrier " designations were changed to " tactical airlift " . Some U . S . Caribou were captured by North Vietnamese forces and remained in service with that country through to the late 1970s . Following the war in Vietnam , all USAF Caribous were transferred to Air Force Reserve and Air National Guard airlift units pending their replacement by the C - 130 Hercules in the 1980s . All C - 7s have now been phased out of U . S . military service , with the last example serving again under U . S . Army control through 1985 in support of the U . S . Army ' s Golden Knights parachute demonstration team . Other notable military operators included Australia , Brazil , Canada , India , Malaysia and Spain . The Royal Australian Air Force retired its last Caribou , " A4 - 140 " , on 27 November 2009 . The aircraft , which was manufactured in 1964 , was donated to the Australian War Memorial , Canberra . Brazil ' s Caribous are slowly being replaced by more modern EADS CASA C - 295 turboprop cargo aircraft . Civilian operations . After retirement from military use , several examples of the Caribou have been purchased by civilian operators for deployment in areas with small airfields located in rugged country with few or poor surface transport links .