De Havilland Canada DHC-4A Caribou

     Notes: This Canadian cargo aircraft comes in civilian and military versions.  The civil version seats 30 passengers, while the military version carries 32 troops.  This aircraft is used by Canada (where it is known as the CC-108), the US (where it is known as the C-7A), Australia, Cameroon, Costa Rica, Malaysia, Vietnam, and Thailand.  The Caribou is used by many bush pilots in Canada and Alaska. It is noted for its use by the CIA’s Air America during the Vietnam War, and for being “the only RAAF plane ever hijacked” (an interesting story in of itself). It is mostly retired from military service, but remains in use by civilian companies and relief organizations. It is a basic transport first built in 1958. US Army Caribous were at first designated CV-2.

     The Caribou is a light transport with STOL takeoff and landing characteristics, and able to remain in the air at slow speeds.  The wingspan is long, but the wings are narrow, and have wide flaps for its STOL mission.  The tail is tall and well off the ground, beyond the rear cargo ramp. The Caribou is powered by a pair of piston engines set into the inner wing; these are Pratt & Whitney R-2000-7M2 Twin Wasps with 1450 horsepower each. The DHC-4A has strengthened fuselage ribs and has a higher weight than the stock DHC-4. The DHC-4T is a DHC-4A that is powered by a pair of Pratt & Whitney PT-6A-67T turboprop engines that produce 1294 horsepower each and are more fuel efficient, though lower in power than the DHC-4 and 4A, and the engines are lighter in weight than the Twin Wasp. The DHC-4T was test flown and certified, but has not yet been produced in scale.

De Havilland Canada DHC-5 Buffalo

    Notes: This is a turboprop, STOL, stretched version of the Caribou.  Except for the distinctive T-tail, the Buffalo retains the lines of the Caribou (and at first was designated the Caribou II). It is known as the CC-115 in Canadian service, and the C-8A in US service.  It was also sold to about 20 world air forces. The US Air Force saw them as an expensive duplication of the role already filled by the C-123 Provider, and did not take many of the Buffalos other than the four already bought by the Army for evaluation. In addition to the basic cargo aircraft, specially equipped Buffaloes are used for maritime patrol (not detailed here). Several are in use by bush pilots and civilian agencies. Some 126 had been built and sold to a variety of nations by 1986.

     The DHC-5 series is powered by turboprop engines; the DHC-5 is powered by a pair of GE T64-10s developing 2650 horsepower, the DHC-5A by CT64-820-1s developing 2825 horsepower each, and the DHC-5D by CT-820-4s developing 3133 horsepower each. Each increase in engine power allowed the DHC-5 to haul more cargo, while retaining the STOL and rough field capabilities. In 2006, Viking Air of British Columbia purchased the rights to manufacture the DHC-5, and proposed the DHC-5NG (New Generation), powered by a pair of Pratt & Whitney PW150s developing 4920 horsepower each.  No such manufacturing has yet taken place, though a test airframe with the PW150 engines has been produced and flown.