De Havilland Canada DHC-2 Beaver

Development

Origins

Following the end of the Second World War, de Havilland Canada's management team, recognising that there would be a corresponding downturn in military orders in the immediate post-war climate, decided to focus the company's energies upon finding work within the civilian sector. The company had recently hired Punch Dickins as Director of Sales; Dickins carried out an extensive market research program in the form of requesting and collecting feedback from other pilots, to understand what they needed in a new aircraft. It was on the basis of this information from the prospective operators themselves, as opposed to aerodynamic research or fiscal data, that the future aircraft has its origins.

In response, almost without exception, these pilots specified their desire for tremendous extra power and STOL performance, in a design that could be easily fitted with wheels, skis or floats. When de Havilland engineers noted this would result in poor cruise performance, one pilot replied, "You only have to be faster than a dog sled to be a winner". Other suggestions that were seemingly mundane, but important in the bush plane world, included the installation of full-sized doors on both sides of the aircraft, which meant that it could be readily loaded no matter which side of a dock it tied up on; the doors were also made wide enough to allow for a 44 Imperial gallon drum to be rolled up into the aircraft.

On 17 September 1946, de Havilland officially put together a design team consisting of Fred Buller, Dick Hiscocks, Jim Houston and Wsiewołod Jakimiuk, led by Phil Garratt. The new aircraft was designed to be all-metal (unlike older designs, like the Noorduyn Norseman), using "steel from the engine to the firewall, heavy aluminium truss frames with panels and doors throughout the front seat area, lighter trusses toward the rear and all monocoque construction aft". At the time, de Havilland Canada was still a British-owned company and there were plans to fit the evolving design with the British de Havilland Gipsy engine. As a result of its comparatively limited power, the wing area was greatly increased in order to maintain STOL performance. When Pratt & Whitney Canada offered to supply war-surplus 450 hp (340 kW) Wasp Junior radial engines at a low price, the aircraft ended up with extra power as well as the original long wing. The result was unbeatable STOL performance for an aircraft of its size.

In line with the convention for aircraft produced by de Havilland Canada being named after animals, it was decided that the new bush plane would be named after the beaver, which was known for its hard-working nature. On 16 August 1947, the maiden flight of the DHC-2 Beaver was in Downsview, Ontario; it was flown by Second World War flying ace Russell Bannock. After completing its flight test programme, the prototype received several adjustments and improvements in order for it to serve as a flying demonstration model ready for the sales circuit. The prototype was ultimately sold to Central British Columbia Airways, as a routine day-to-day working air-taxi airplane and continued to fly as such with various air-taxi operators until 1980, after which it was retired and preserved. In April 1948, the first production aircraft was delivered to the Ontario Department of Lands and Forests, who had been a design partner.

Production

Initial sales were slow, perhaps two or three a month but as the plane was demonstrated sales started to improve. A key event in the Beaver's history occurred the next year when the US Army commenced its search for a new utility aircraft to replace their fleet of Cessnas. The competition quickly boiled down to the Beaver and the Cessna 195. The Beaver won and during the Korean War, the US Army ordered 970, more than half of the overall production run for the type.

Soon, the Beaver grew to become an export success as orders for the type increased from customers around the world. Individual military services of more than 30 different nations would ultimately be included amongst its operators. In later life, as the type was gradually phased out of military service, many examples underwent conversion work so that they could continue to be operated as civilian aircraft instead. During the 1960s, de Havilland developed an improved model of the Beaver, the Mk.III Turbo Beaver, which was equipped with a Pratt & Whitney Canada PT6 turboprop engine. A total of sixty aircraft were built during the late 1960s. In 1967, when production of the type finally ceased, a total of 1,657 DHC-2 Beavers had been constructed.

The Beaver was designed for flight in rugged and remote areas of the world. Its STOL capability made it ideal for areas normally only accessible by canoe or foot. Because the aircraft often flies to remote locations and in cold climates, its oil reservoir filler is located in the cockpit and oil can be filled in flight. A series of upgrades to the basic design were incorporated. One major customer introduced the use of flat steps replacing the earlier tubes, a feature now almost universal.