The de Havilland Aircraft Company of Canada DHC-4 Caribou was designed to provide military operators with a twin-engine STOL (Short Take off & Landing) cargo transport aircraft, with greater capacity than that of the DHC-3 Otter. The type also offered a rear loading capability. The prototype DHC-4 Caribou (CF-KTK-X) was flown for the first time on 30th July 1958.
Like the DHC-3 Otter, the Caribou was a rugged STOL aircraft which was ideally suited for operations from unprepared remote airfields and boasted a capacity of up to 32 troops, or some 8,000 lbs of payload. Power was provided by two 1,450hp Pratt and Whitney Twin Wasp radial engines.
In total, some 307 were built in Canada and it found a ready market with a number of military users at home and around the world. A measure of the aircraft’s success is demonstrated by the fact that some 32 different nations employed the aircraft, predominantly in military roles. Significant users included the US Army / US Air Force (159 CV-2 / C-7), Australia (31 aircraft serving until 2009), Spain (35 aircraft), India (20 + 4 ex-Ghana), Canada (9), Ghana (8), Kenya (6). A smaller number of aircraft were also delivered for commercial operations worldwide.
In 1966, the US Army relinquished its DHC-4 Caribou fleet to the US Air Force, in exchange for the removal of controls on its use of rotary wing aircraft (helicopters). During the Vietnam War some DHC-4 Caribou aircraft were captured by North Vietnamese forces and these stayed in service in Vietnam well into the 1970's. Following the end of the Vietnam War however, the majority of the US Air Force Caribou fleet were replaced by C-130 Hercules, although the final DHC-4 Caribou was retired from US Air Force service as late as 1985, where it had been serving as the jump-platform for the US Army Golden Knights Parachute Display Team.
The last Caribou aircraft in military service anywhere in the world was the Caribou (A4-140) in Australia, which was finally retired in November 2009.