KING BEAVER TO CARRY TON PAYLOAD
FIRST performance and specification details have now become available forecasting what is probably the most promising prototype in the history of Canadian commercial aircraft design. The King Beaver, a high-performance, 8-l4-passenger bushplane is now under construction at the de Havilland plant near Toronto. The prototype is expected to fly late in the fall.
A considerably larger version of the well-known D-H Beaver, the "King" will feature a large cabin (12 ft. long, 5 ft. wide, 5 ft. high, volume :260 cu. ft.); 7,200-lb. gross weight compared with the Beaver's 4,820 lb.); all-metal construction; and extra-large doors.
While stepping up the cabin volume and load-carrying capacity the designers have been able to retain the distinctive take-off performance of the Beaver. The latter, as a seaplane, fully loaded and in still air at sea level, will take off and clear a 50-ft. obstacle in 1,195 ft. (19 seconds). The King Beaver seaplane, with a payload of 1,900 lb., is expected to take under similar conditions in 1,200 ft., or about the same distance.
This has been achieved by stepping up the power from 450 hp. to 600 hp.with a Pratt & Whitney Wasp H-R 1340 engine (geared and fitted with a new type three-bladed propeller) while retaining the high-lift amply-flapped wing characteristics of the Beaver.
Construction of jigs and fixtures for the prototype is well underway and, as in the case of the Beaver, these will be used for the production aircraft. The prototype probably will make its first flight in September or October. It is anticipated that a limited number of the King Beavers will be delivered to customers next year.
However, with substantial Beaver commitments on the books de Havilland is planning in terms of 1953 for King Beaver deliveries.
As a general purpose aircraft the King will carry eight to 14 passengers or one ton payload. Span is 58 ft., length 42 ft., height 10 ft. 6 in. In addition to the 260-cu.-ft. cabin volume there is an extra baggage locker 27 in. by 50 in, by 50 in. The floors are reinforced for cargo carrying. Behind the rear bulkhead there is a circular floor hatch which can be used for camera installation or for dropping either cargo or paratroops.
The cabin doors are 46 ft. wide on the port side and 30 in. on the starboard side. As in the Beaver, there are crew doors forward, on both sides.
As an ambulance, the King Beaver will carry six litters and four seats or three litters and seven seats.
The high wing is of rectangular plan form and strut-braced with slotted flaps and drooping ailerons. The wing section is designed to provide maximum lift coeffcient and a docile stall. Horizontal tail area is generous to provide for a large c.g. range and ample static stability margins for all flap and power settings. All controls will be mass balanced to eliminate any possibility of flutter and full aerodynamic balance will be provided to reduce pilot fatigue and ensure good stick-free stability.
Construction Details -- The wing is of constant thickness and will be in two panels, left and right, attaching to the sides of the fuselage at roof level. A bolt attaches each spar root.
An NACA type double slotted flap extends from root to tip of the wing. A slotted type aileron extends from the mid-section of the flap to the tip. The wing tips are removable.
The fuselage consists of three main sections; a short front section comprising the firewall, flying and engine controls and panels, windscreen and front floor, and pilot's door; a centre section containing main passenger and cargo compartments, fuel tanks and main doors; and a rear section extending from the rear of the cabin bulkhead.
Canadian Aviation , August 1951, p. 16-17