First the DHC-1 chipmunk, then the DHC-2 Beaver, next the DHC-3 Otter and now -- the DHC-4 Caribou, which, like its forebears, should have a long and successful career.

        It is only since the end of the last war that the de Havilland Aircraft Company of Canada began producing original designs, and the quartet mentioned above have shown the world that the company is not lacking in ideas.

        The Caribou made its first flight on 30th July, and the prototype is one of two ordered by the Canadian Government and will be used for extensive evaluation trials. By February next it is expected that the first five machines ordered by the U.S. Army will be delivered, and at the same time work will start on the first batch of twenty production aircraft. The first civil Caribou should be ready by March next year.

        The development of the Caribou was under consideration by de Havilland Canada for over two years before the decision to go ahead was made in January 1957. During this time extensive design studies were undertaken by the design team, and at one phase it was proposed to fit a twin-finned tail unit. This was dropped in favour of the present single fin, which is one of the largest ever for an aircraft of the size of the Caribou.

        Basically the Caribou is an all-weather utility aircraft designed to offer low-cost transportation of passengers and cargo, or combinations of both, over the world's air routes, particularly in undeveloped areas.

        Powerplants chosen are a pair of Pratt & Whitney R-2000-7M2s turning Hamilton Standard hydraulic three-blade constant-speed full-feathering propellers. The engines are built as interchangeable power pods, and a portable engine change crane is available and can be fitted to the top of the wing for in-the-field maintenance. Cowlings are "petal" type and have five hinged panels. Exhaust augmentors are used.

        The fuselage is of all-metal construction and is sharply swept up at the rear. This rear portion contains a large cargo door built in two parts. The upper portion retracts into the roof structure and operates in flight to facilitate aerial delivery. The lower section operates as a ramp which can be adjusted to truck-bed height. Passengers can enter the cabin through doors in the left and right sides of the rear fuselage. Crew entrance is made through a door under the belly when the cabin is fully loaded.

        Wing assembly comprises a downward cranked centre section and two tapered outer panels built around two main spars. All fuel is carried in the outer panels which each contain ten interconnected flexible-bladder fuel cells having a total capacity of 700 gal. Double slotted flaps-wingtip to wingtip-are fitted with four sections on each wing. Of the four double slotted flaps the lower portions of the two outer sections are also ailerons.

        As a freighter the Caribou will carry 7,383 lb. of cargo over a stage distance of 200 miles, but this drops to 5,368 lb. over 800 miles.

        As a passenger plane it can carry twenty-seven passengers, 1,863 lb. of baggage and cargo over 200 miles, while over 800 miles twenty-five passengers could be carried with 175 lb. of baggage.

        Military versions are designed to carry twenty-eight full, equipped troops or twenty-two paratroops. For evacuation it will carry fourteen stretchers and ten seats for attendants and or walking cases. The cabin with a 1,000 cu. ft. capacity measures 25 ft. in length and is 6 ft. 11 in. wide.

        When used for mixed passenger/cargo work the twenty-seven utility seats can be folded against the cabin wall. Altematively, the aircraft can be fitted with three longitudinal floor rails which permit rapid adjustment of seat spacing to suit loading requirements. For heavy loads the cabin will accommodate two Army "jeeps" or similar vehicles.

        For emergency exits an escape hatch is provided in the roof over the pilot’s head in addition to the entry hatch in the bell of the cockpit compartment. Three passenger emergency exits are provided in the cabin . . . in addition the upper section of the rear cargo door is jettisonable, providing a fourth emergency exit from the cargo compartment.

        The main undercarriage legs are single units and have two stage shock-absorbing action. The long stroke is designed to absorb a 14 1/2 ft./sec. rate of descent and the short stroke action comes in to provide less damping while the aircraft is taxi-ing over rough ground. The main legs retract back into the engine nacelles. The nose wheels retract backwards and when extended the wheel doors close to prevent mud, stones and other objects from entering the wheel-well. Emergency system for the nosewheel includes a hand pump and a compressed air bottle. The tin wheels are "gravity" extended.

        Several turboprop versions of the Caribou are on the drawing boards and one of these is said to use Lycoming T55 turboprops of 1,680 s.h.p.