De Havilland Canada DHC-2 Beaver: Διαφορά μεταξύ των αναθεωρήσεων

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Έκδοση από την 15:49, 29 Δεκεμβρίου 2007

Πρότυπο:Lowercase Πρότυπο:Infobox Aircraft The de Havilland Canada DHC-2 Beaver is one of the most famous bush planes in the world. After World War II, de Havilland Canada was looking to produce a plane suited to operations in the extremes of the Canadian north.

The Beaver has become a symbol of the Canadian north, and has since found use as a bush plane all over the world; the international ICAO designation for flight plans is DHC2. The type is used for aerial application; (crop dusting and aerial topdressing), and has been widely used by armed forces as a utility aircraft; the U.S. Army Air Corps purchased several hundred. Nine DHC-2s are still in service with the US Air Force Auxiliary (Civil Air Patrol) for search and rescue. A Royal New Zealand Air Force Beaver supported Sir Edmund Hillary's expedition to the South Pole. Over 1,600 Beavers were produced.

Due to this success, the Royal Canadian Mint commemorated the Beaver on a special edition Canadian quarter in November 1999.

Design and development

Ontario Ministry of Natural Resources deHavilland DHC-2 Mk 3 Turbo Beavers on amphib floats in Dryden, Ontario in 1995

After extensive consultation with bush pilots, de Havilland Canada began production of the Beaver —a reliable, single-engine monoplane that could be easily fitted with wheels, skis, or floats. The Beaver was designed for flight in rugged and remote areas of the world. Its short takeoff and landing capability made it ideal for areas normally only accessible by canoe or foot. Because it often flies to remote locations (that often are in cold climates) its oil reservoir filling spout is located in the cockpit itself and the oil can be refilled while the aircraft is in flight. The first flight of the DHC-2 Beaver was in Downsview, Ontario by Second World War flying ace Russ Bannock on 16 August 1947, with the first production aircraft being delivered in April 1948. The plane was an immediate success within the Canadian aviation community. The de Havilland company hired veteran bush pilot Punch Dickins as their Director of Sales and when production finally ceased in 1967, 1,657 DHC-2 Beavers had been built.

Operational history

Despite the fact that production ceased in 1967, hundreds of Beavers are still flying—many of them heavily modified to adapt to changes in technology and needs. Kenmore Air of Kenmore, Washington provides Beaver and Otter airframes with zero-hour fatigue-life ratings, and owns dozens of supplemental type certificates (STCs) for aircraft modifications. These modifications are so well-known and desirable in the aviation community that the rebuilt Beavers are often called "Kenmore Beavers" or listed as having "Kenmore mods" installed.^[1] A 1950s Beaver that originally sold for under US $50,000 can now be seen for sale at prices reaching US $500,000.

The original Pratt & Whitney Wasp radial engine of the Beaver is now out of production, so repair parts are getting harder to find. Some aircraft conversion stations have addressed this problem by replacing the piston engine with a turboprop engine such as the Pratt & Whitney Canada PT-6. The added power and lighter installed weight, together with greater availability of kerosene fuel instead of high-octane aviation gasoline, make this a desirable modification.

Harrison Ford owns a DHC-2 Beaver (N28S), and has commented that it is his favourite among his entire fleet of private aircraft. The United States military continues to operate two DHC-2s at the United States Naval Test Pilot School, where they are used to instruct students in the evaluation of lateral-directional flying qualities and to tow gliders.

The DHC-2 Beaver is sometimes used by skydiving operators due to its good climb rate. When fitted with a roller door that can be opened in flight, it can quickly ferry eight skydivers to 13,000 ft (3,950 m).

Recent developments

At one point in its production, plans to license build the type in New Zealand were proposed. Although there have been rumours of Canadian companies manufacturing new Beavers, it remains an out-of-production aircraft. The remaining tooling was purchased by Viking Air of Victoria, Canada which manufactures replacement parts for most of the early de Havilland line. On February 24, 2006, Viking purchased the type certificates from Bombardier Aerospace for all the original de Havilland designs^[2]. The ownership of the certificates gives Viking the exclusive right to manufacture new Beavers.

In a news report on 4 April 2007 (www.flightglobal.com), Victoria, British Columbia-based Viking said it may restart production of the single engine DHC-3 Otter and possibly the DHC-2 Beaver following strong market demand for both aircraft.

In 1987, the Canadian Engineering Centennial Board named the DHC-2 Beaver as one of the top ten Canadian engineering achievements of the 20th century.^[3]

Variants

Beaver I : Single-engined STOL utility transport aircraft.
- Beaver AL Mk 1 : STOL utility transport aircraft for the British Army.
- YL-20 : Test and evaluation aircraft for the US military.
- L-20A Beaver : STOL utility transport aircraft for the US Army, later redesignated U-6A in 1962, 968 built.
- L-20B Beaver : Basically similar to the L-20A, but with minor equipment changes. Six were sold to the US Army. Later redesignated U-6B in 1962.
Beaver II : One aircraft was fitted with an Alvis Leonides radial piston engine.
Turbo-Beaver III : Powered by a 431-kW (578-ehp) Pratt & Whitney PT6A-6 or -20 turboprop engine.
DHC-2/PZL-3S: After-market conversion by Airtech Canada in the 1980s, using current-production PZL-3S radial engines of 600 hp (450 kW)

Operators

Military operators

Specifications (DHC-2)

General Characteristics

Crew: one pilot

Capacity: 6 passengers

Length: 30 ft 3 in (9.22 m)

Wingspan: 48 ft 0 in (14.63 m)

Height: 9 ft 0 in (2.74 m)

Wing area: 250 ft² (23.2 m²)

Empty: 3,000 lb (1,360 kg)

Loaded: 5,100 lb (2,310 kg)

Useful load: 2,100 lb (950 kg)

Powerplant: 1 Pratt & Whitney R-985 Wasp Jr. radial engine, 450 hp (335 kW)

Performance

Maximum speed: 158 mph (255 km/h)

Range: 455 miles (732 km)

Service ceiling: 18,000 ft (5,500 m)

Rate of climb: 1,020 ft/min (5.2 m/s)

References

Notes

↑ «Beaver Rebuild Program». Kenmore Air. Ανακτήθηκε στις 21 Απριλίου 2007.
↑ Viking acquires DeHavilland type certificates Press Release 24 February 2006
↑ Russ Cooper, Winged Workhorse, Canadian Geographic magazine, July/August 2007, p. 26

Bibliography