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101-434: The de Havilland Canada DHC-2 Beaver is a single-engined high-wing propeller -driven short takeoff and landing (STOL) aircraft developed and manufactured by de Havilland Canada . It has been primarily operated as a bush plane and has been used for a wide variety of utility roles, such as cargo and passenger hauling, aerial application ( crop dusting and aerial topdressing ), and civil aviation duties. Shortly after

202-582: A DHC-2 Beaver to an electric aircraft for development and prototype testing, with aspirational palns to eventually to convert its entire fleet. The first test flight of the aircraft took place in Vancouver in December 2019. By 2024, Harbor Air is anticipating the MagniX motor/battery set being airworthiness certified by Transport Canada by the end of 2026, with a plan to get the eBeaver type-certified by

303-684: A Wing Angle Kit which changes the incidence of the wing. Advanced Wing Technologies of Vancouver, British Columbia has developed and certified a new wing for the DHC-2. The FAA Supplemental Type Certificate also raises the aircraft's gross weight to 6,000 lb (2,700 kg). So far, at least two Beavers have been modified in such a manner. In September 2017 the Transportation Safety Board of Canada recommended stall warning devices be mandated for commercial Beaver operators. In March 2019, Harbour Air announced plans to convert

404-464: A bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered , and this plus the absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this was perhaps the first use of aluminium in the construction of an airscrew. Originally, a rotating airfoil behind the aircraft, which pushes it, was called a propeller, while one which pulled from

505-473: A childhood fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu, but powered by rubber bands. By the end of the century, he had progressed to using sheets of tin for rotor blades and springs for power. His writings on his experiments and models would become influential on future aviation pioneers. William Bland sent designs for his "Atmotic Airship" to

606-461: A craft that weighed 3.5 long tons (3.6 t), with a 110 ft (34 m) wingspan that was powered by two 360 hp (270 kW) steam engines driving two propellers. In 1894, his machine was tested with overhead rails to prevent it from rising. The test showed that it had enough lift to take off. One of Pénaud's toys, given as a gift by their father , inspired the Wright brothers to pursue

707-477: A customer supplied 450 hp (340 kW) Pratt & Whitney R-1340 Wasp SC-1 engine as the Norseman Mk.II , but was later re-engined with a 600 hp (450 kW) Pratt & Whitney Wasp S3H-1, its original intended engine, on June 26, 1937 as the prototype for the Norseman Mk.IV . The Mk.IV was the definitive per-war model but the production run might have ended at a few hundred examples if not for

808-747: A desirable modification, but at a high cost. The Beaver was deployed by the British Army Air Corps during the Troubles , at least until 1979, for photo-reconnaissance missions. One of them was hit seven times by machine gun fire in South County Armagh , near the border with the Republic of Ireland in November 1979, while taking photos of an IRA checkpoint. The border crossing where the action took place became known to

909-416: A fixed-pitch prop once airborne. The spring-loaded "two-speed" VP prop is set to fine for takeoff, and then triggered to coarse once in cruise, the propeller remaining coarse for the remainder of the flight. After World War I , automatic propellers were developed to maintain an optimum angle of attack. This was done by balancing the centripetal twisting moment on the blades and a set of counterweights against

1010-730: A jumping-off point for remote communities in Northwestern Ontario , promotes itself as The Norseman Capital of the World . Each summer in July, the "Norseman Floatplane Festival" brings Norseman aircraft to Red Lake as the centrepiece of a community based weekend festival ranging from stage entertainment, children's games and rides, contests, cultural and historical displays and street vendors with craft and specialty booths. Canadian Second World War ace George Beurling died in May 1948 landing

1111-467: A large number of blades. A fan therefore produces a lot of thrust for a given diameter but the closeness of the blades means that each strongly affects the flow around the others. If the flow is supersonic, this interference can be beneficial if the flow can be compressed through a series of shock waves rather than one. By placing the fan within a shaped duct , specific flow patterns can be created depending on flight speed and engine performance. As air enters

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1212-528: A low- drag wing and as such are poor in operation when at other than their optimum angle of attack . Therefore, most propellers use a variable pitch mechanism to alter the blades' pitch angle as engine speed and aircraft velocity are changed. A further consideration is the number and the shape of the blades used. Increasing the aspect ratio of the blades reduces drag but the amount of thrust produced depends on blade area, so using high-aspect blades can result in an excessive propeller diameter. A further balance

1313-415: A propeller efficiency of about 73.5% at cruise for a Cessna 172 . This is derived from his "Bootstrap approach" for analyzing the performance of light general aviation aircraft using fixed pitch or constant speed propellers. The efficiency of the propeller is influenced by the angle of attack (α). This is defined as α = Φ - θ, where θ is the helix angle (the angle between the resultant relative velocity and

1414-453: A propeller suffers when transonic flow first appears on the tips of the blades. As the relative air speed at any section of a propeller is a vector sum of the aircraft speed and the tangential speed due to rotation, the flow over the blade tip will reach transonic speed well before the aircraft does. When the airflow over the tip of the blade reaches its critical speed , drag and torque resistance increase rapidly and shock waves form creating

1515-596: A roller door that can be opened in flight, it can quickly ferry eight skydivers to 13,000 ft (4,000 m). The DHC-2 is popular with air charter companies, police forces and small air taxi operators as well as private individuals and companies. Both the Royal Canadian Mounted Police and Finnish Border Guard operate the aircraft. Several small airline companies in British Columbia use Beavers on scheduled routes from Vancouver to

1616-454: A sharp increase in noise. Aircraft with conventional propellers, therefore, do not usually fly faster than Mach 0.6. There have been propeller aircraft which attained up to the Mach 0.8 range, but the low propeller efficiency at this speed makes such applications rare. The tip of a propeller blade travels faster than the hub. Therefore, it is necessary for the blade to be twisted so as to decrease

1717-417: A spring and the aerodynamic forces on the blade. Automatic props had the advantage of being simple, lightweight, and requiring no external control, but a particular propeller's performance was difficult to match with that of the aircraft's power plant. The most common variable pitch propeller is the constant-speed propeller . This is controlled by a hydraulic constant speed unit (CSU). It automatically adjusts

1818-520: A wound-up spring device and demonstrated it to the Russian Academy of Sciences . It was powered by a spring, and was suggested as a method to lift meteorological instruments. In 1783, Christian de Launoy , and his mechanic , Bienvenu, used a coaxial version of the Chinese top in a model consisting of contrarotating turkey flight feathers as rotor blades, and in 1784, demonstrated it to

1919-529: Is considered a 'working' aircraft, which was designed for vigorous use. In addition to cargo, passengers can also be carried; when appropriately fitted out, the Beaver Mk.I can accommodate up to seven passengers while the more spacious Beaver Mk.III can hold a maximum of 11. Various alterations have been approved, including alternative seating arrangements, enlarged cargo doors, larger windows and smaller batteries have been approved for use. During takeoff, both

2020-423: Is equipped with a 680 shp (510 kW) PT6A-34 turboprop engine. The Beaver is functionally shaped in order to accommodate a useful and sizable payload, typically close to 2,000 lb (910 kg), even when equipped with floats. While the front doors are narrow, the aft doors are wider, having been designed to facilitate the loading of 45 imperial gallon barrels, either upright or on their sides. The Beaver

2121-455: Is hydraulic, with engine oil serving as the hydraulic fluid. However, electrically controlled propellers were developed during World War II and saw extensive use on military aircraft, and have recently seen a revival in use on home-built aircraft. Another design is the V-Prop , which is self-powering and self-governing. On most variable-pitch propellers, the blades can be rotated parallel to

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2222-479: Is suitable for airliners, but the noise generated is tremendous (see the Antonov An-70 and Tupolev Tu-95 for examples of such a design). Forces acting on the blades of an aircraft propeller include the following. Some of these forces can be arranged to counteract each other, reducing the overall mechanical stresses imposed. The purpose of varying pitch angle is to maintain an optimal angle of attack for

2323-409: Is that using a smaller number of blades reduces interference effects between the blades, but to have sufficient blade area to transmit the available power within a set diameter means a compromise is needed. Increasing the number of blades also decreases the amount of work each blade is required to perform, limiting the local Mach number – a significant performance limit on propellers. The performance of

2424-489: Is used to help slow the aircraft after landing and is particularly advantageous when landing on a wet runway as wheel braking suffers reduced effectiveness. In some cases reverse pitch allows the aircraft to taxi in reverse – this is particularly useful for getting floatplanes out of confined docks. Counter-rotating propellers are sometimes used on twin-engine and multi-engine aircraft with wing-mounted engines. These propellers turn in opposite directions from their counterpart on

2525-673: The British Commonwealth Air Training Plan . USAAF Colonel Bernt Balchen was establishing a staging route across Greenland to ferry aircraft to Europe. He required a transport rugged enough to survive in the harsh conditions of the Arctic. After evaluating six Norsemans diverted from the RCAF order, late in 1941, he recommended the purchase of the Norseman Mk.IV specially modified to USAAF requirements as

2626-615: The C-64 Norseman , is a Canadian single-engine bush plane designed to operate from unimproved surfaces. Distinctive stubby landing gear protrusions from the lower fuselage make it easily recognizable. Introduced in 1935, the Norseman remained in production for almost 25 years with over 900 produced. A number of examples remain in commercial and private use to this day. Norseman aircraft are known to have been registered or operated in 68 countries and also have been based and flown in

2727-531: The Canada Car and Foundry acquired the rights to the design and produced the Norseman Mk.V , a civilian version of the UC-64. To further improve the basic design, "Can Car" designed and built the Norseman Mk.VII with a bigger engine, a new all-metal wing and greater cargo capacity but it never went into production. With large Korean War commitments at that time, the company put it into temporary storage where it

2828-545: The French Academy of Sciences . A dirigible airship was described by Jean Baptiste Marie Meusnier presented in 1783. The drawings depict a 260-foot-long (79 m) streamlined envelope with internal ballonets that could be used for regulating lift. The airship was designed to be driven by three propellers. In 1784 Jean-Pierre Blanchard fitted a hand-powered propeller to a balloon, the first recorded means of propulsion carried aloft. Sir George Cayley , influenced by

2929-465: The Tupolev Tu-95 propel it at a speed exceeding the maximum once considered possible for a propeller-driven aircraft using an exceptionally coarse pitch. Early pitch control settings were pilot operated, either with a small number of preset positions or continuously variable. The simplest mechanism is the ground-adjustable propeller , which may be adjusted on the ground, but is effectively

3030-488: The Tupolev Tu-95 , which can reach 575 mph (925 km/h). The earliest references for vertical flight came from China. Since around 400 BC, Chinese children have played with bamboo flying toys . This bamboo-copter is spun by rolling a stick attached to a rotor between one's hands. The spinning creates lift, and the toy flies when released. The 4th-century AD Daoist book Baopuzi by Ge Hong (抱朴子 "Master who Embraces Simplicity") reportedly describes some of

3131-494: The U.S. Air Force Auxiliary (Civil Air Patrol) for search and rescue. By 1967, over 1,600 Beavers had been constructed prior to the closure of the original assembly line. Various aircraft have been remanufactured and upgraded. Additionally, various proposals have been made to return the Beaver to production. The Beaver's versatility and performance led to it being the preferred aircraft of bush pilots servicing remote locations in

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3232-527: The US Army Corps of Engineers . Other Allied air forces also placed orders, for 43 Norseman Mk.IVs. The RCAF ordered an additional 34 aircraft as Norseman Mk.VI s. Noorduyn was still the sole manufacturer, but when the USAAF considered ordering a larger number of C-64As, license production of 600 by Aeronca Aircraft Corp. (Middletown, Ohio) was planned before being cancelled in 1943. Major Glenn Miller

3333-662: The YC-64A . After the US entry into the Second World War, the USAAF placed the first of several orders for a production version C-64A Norseman . The principal differences included two fuselage belly tanks raising the standard fuel capacity to 201 imp gal (910 L; 241 US gal), and an additional cabin fuel tank of 32 imp gal (150 L; 38 US gal) that could also be installed. These changes resulted in an increase of 950 lb (430 kg) in

3434-485: The ailerons and flaps are lowered, which is a relatively uncommon design approach but results in substantially elevated STOL performance. The flaps can be deployed to an extreme range, extending out at full to a 58-degree position; the flight manual notes that the full setting is recommended only for performing emergency landings. In the skies, the Beaver is relatively easy to handle, having been described as possessing light and comfortable controls. Effective application of

3535-619: The rudder is necessary to counteract adverse yaw . It should be flown with a relatively nose-low pitch attitude to maintain airspeed. It is very easy to land, even in moderately rough water. 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

3636-434: The type certificates from Bombardier Aerospace for all the original de Havilland designs, including the Beaver. The ownership of the certificates gives the company the exclusive right to manufacture new aircraft. Viking has stated its interest in the potential restart of production of the Beaver, and commented that, dependent upon market demand, the firm may offer two separate models of the Beaver, one intended to be close to

3737-471: The 21st century, while the tooling and type certificate for the Beaver have been acquired by Viking Air who continue to produce replacement components and refurbish examples of the type. 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

3838-625: The Arctic and Antarctic regions. Designed by Robert B. C. Noorduyn , the Noorduyn Norseman was produced from 1935 to 1959, originally by Noorduyn Aircraft Ltd. and later by the Canadian Car and Foundry company. With the experience of working at Fokker , Bellanca and Pitcairn-Cierva , Noorduyn decided to create his own design in 1934. Along with his colleague, Walter Clayton, Noorduyn created his original company, Noorduyn Aircraft Limited, in early 1933 at Montreal , which then

3939-575: 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

4040-442: The Beaver has had a lengthy service life and many examples have been remanufactured or have otherwise received life extension modifications. The Beaver is typically powered by a single 450 hp (340 kW) Pratt & Whitney R-985 Wasp Junior radial engine . In order to provide the necessary weight balance for optimal loading flexibility, the engine was mounted as far rearwards as possible, resulting in elements intruding into

4141-567: 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

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4242-582: The British Army as "Beaver Junction". Operators of significant numbers of piston-Beavers in early 2008 include Air Saguenay and Harbour Air in Canada and Kenmore Air in the US. American actor Harrison Ford owns a DHC-2 Beaver; he is known for referring to it as being his favourite among his entire fleet of private aircraft. The Civil Air Patrol operated many of the DHC-2 Beaver, where it

4343-582: The Canadian north, and it is considered by aviation historians to be a Canadian icon. In 1987, the Canadian Engineering Centennial Board named the DHC-2 one of the top ten Canadian engineering achievements of the 20th century. The Royal Canadian Mint honoured the aircraft on a special edition Canadian quarter in November 1999, and on a 50-cent commemorative gold coin in 2008. Large numbers continue to be operational into

4444-535: The Great Exhibition held in London in 1851, where a model was displayed. This was an elongated balloon with a steam engine driving twin propellers suspended underneath. Alphonse Pénaud developed coaxial rotor model helicopter toys in 1870, also powered by rubber bands. In 1872 Dupuy de Lome launched a large navigable balloon, which was driven by a large propeller turned by eight men. Hiram Maxim built

4545-473: The Norseman was first fitted with floats, then skis and, finally, wheels. The final design looked much like Noorduyn's earlier Bellanca Skyrocket , a strut-braced high-wing monoplane with a welded steel tubing fuselage. Attached wood stringers carried a fabric covering that faired out the more refined shape. Its wing had a wood structure covered in fabric, except for steel tubing in the flaps and ailerons. The divided landing gear were fitted to fuselage stubs with

4646-578: The Sunshine Coast, Vancouver Island as well as numerous nearby smaller islands. The largest of these airlines is Harbour Air . As of August 2023, there have been 351 incidents involving the DHC-2 and 739 deaths. A select few are listed: Data from The Encyclopedia of World Aircraft , BAE Systems General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists Propeller (aircraft) The propeller attaches to

4747-534: The advent of the Second World War . By 1940, Noorduyn had sold only 17 aircraft, primarily to commercial operators in Canada's north and to the Royal Canadian Mounted Police . With the outbreak of war, demand for a utility transport led to large military orders. The Royal Canadian Air Force and the United States Army Air Forces became the two largest operators. The RCAF ordered 38 Norseman Mk.IVW s for radio and navigational training for

4848-399: The air in the propeller slipstream. Contra-rotation also increases the ability of a propeller to absorb power from a given engine, without increasing propeller diameter. However the added cost, complexity, weight and noise of the system rarely make it worthwhile and it is only used on high-performance types where ultimate performance is more important than efficiency. A fan is a propeller with

4949-428: The aircraft maintain speed and altitude with the operative engines. Feathering also prevents windmilling , the turning of engine components by the propeller rotation forced by the slipstream; windmilling can damage the engine, start a fire, or cause structural damage to the aircraft. Most feathering systems for reciprocating engines sense a drop in oil pressure and move the blades toward the feather position, and require

5050-405: The airflow to stop rotation of the propeller and reduce drag when the engine fails or is deliberately shut down. This is called feathering , a term borrowed from rowing . On single-engined aircraft, whether a powered glider or turbine-powered aircraft, the effect is to increase the gliding distance. On a multi-engine aircraft, feathering the propeller on an inoperative engine reduces drag, and helps

5151-410: The angle of attack of the blade gradually and therefore produce uniform lift from the hub to the tip. The greatest angle of incidence, or the highest pitch, is at the hub while the smallest angle of incidence or smallest pitch is at the tip. A propeller blade designed with the same angle of incidence throughout its entire length would be inefficient because as airspeed increases in flight, the portion near

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5252-583: The aviation community, rebuilt Beavers are often called "Kenmore Beavers" or listed as having "Kenmore mods" installed. The original Wasp Jr radial engine of the Beaver is long 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 PT6 . The added power and lighter installed weight, together with greater availability of kerosene fuel instead of high-octane aviation gasoline, make this

5353-476: The basic design were incorporated. One major customer introduced the use of flat steps replacing the earlier tubes, a feature now almost universal. In 1987, the Canadian Engineering Centennial Board named the DHC-2 as one of the top ten Canadian engineering achievements of the 20th century. At one point in its production, plans to license-build the Beaver in New Zealand were proposed. The remaining tooling

5454-407: The blade pitch in order to maintain a constant engine speed for any given power control setting. Constant-speed propellers allow the pilot to set a rotational speed according to the need for maximum engine power or maximum efficiency, and a propeller governor acts as a closed-loop controller to vary propeller pitch angle as required to maintain the selected engine speed. In most aircraft this system

5555-440: The blade rotation direction) and Φ is the blade pitch angle. Very small pitch and helix angles give a good performance against resistance but provide little thrust, while larger angles have the opposite effect. The best helix angle is when the blade is acting as a wing producing much more lift than drag. However, 'lift-and-drag' is only one way to express the aerodynamic force on the blades. To explain aircraft and engine performance

5656-403: The blade tips approach the speed of sound. The maximum relative velocity is kept as low as possible by careful control of pitch to allow the blades to have large helix angles. A large number of blades are used to reduce work per blade and so circulation strength. Contra-rotating propellers are used. The propellers designed are more efficient than turbo-fans and their cruising speed (Mach 0.7–0.85)

5757-494: 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

5858-499: The carriage of up to 2,450 lb (1,110 kg) of freight, a roughly 25 per cent increase in usable payload. By August 1995, Viking completed its 30th Turbo Beaver conversion. The firm has also developed and marketed other improvements for the type, such as an advanced wing and modified floats. Other manufacturers have also offered aftermarket upgrades and modifications for the type, such as re-engining programmes by Orenda Aerospace and Wipaire . On 24 February 2006, Viking purchased

5959-471: The cockpit space, such as the oil tank being positioned within the center console between the pilot and copilot's feet and the main fuel tank within the forward belly of the aircraft, which also improves accessibility for replenishment. Many Beavers have had wingtip tanks also installed; careful fuel management between the various fuel tanks is required throughout flights in order to maintain the aircraft's center of gravity . The remanufactured DHC-2T Turbo Beaver

6060-452: 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

6161-456: 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,

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6262-474: The design of the original batch, and another incorporating various improvements such as new avionics, engines, and doors, as well as likely being stretched to provide increased internal space. Stolairus Aviation of Kelowna, British Columbia has developed several modifications for the DHC-2 including a STOL Kit which modifies the wing with a contoured leading edge, flap-gap seals, wing fences and drooped wingtips for increased performance. Stolairus has also developed

6363-467: The dream of flight. The twisted airfoil (aerofoil) shape of an aircraft propeller was pioneered by the Wright brothers. While some earlier engineers had attempted to model air propellers on marine propellers , the Wright Brothers realized that a propeller is essentially the same as a wing , and were able to use data from their earlier wind tunnel experiments on wings, introducing a twist along

6464-455: The duct needs to be shaped in a different manner than one for higher speed flight. More air is taken in and the fan therefore operates at an efficiency equivalent to a larger un-ducted propeller. Noise is also reduced by the ducting and should a blade become detached the duct would help contain the damage. However the duct adds weight, cost, complexity and (to a certain degree) drag. Noorduyn Norseman The Noorduyn Norseman , also known as

6565-575: The duct, its speed is reduced while its pressure and temperature increase. If the aircraft is at a high subsonic speed this creates two advantages: the air enters the fan at a lower Mach speed; and the higher temperature increases the local speed of sound. While there is a loss in efficiency as the fan is drawing on a smaller area of the free stream and so using less air, this is balanced by the ducted fan retaining efficiency at higher speeds where conventional propeller efficiency would be poor. A ducted fan or propeller also has certain benefits at lower speeds but

6666-409: The end of 2027 and able to enter commercial service. The de Havilland Canada DHC-2 Beaver is a single-engined high-wing propeller -driven STOL aircraft, principally operated as a bush plane and other utility roles, such as cargo and passenger hauling, aerial application ( crop dusting and aerial topdressing ), and general civil aviation purposes; aviation publication Plane & Pilot described

6767-455: The end of the Second World War , de Havilland Canada decided to orient itself towards civilian operators. Based on feedback from pilots, the company decided that the envisioned aircraft should have excellent STOL performance, all-metal construction, and accommodate many features sought by the operators of bush planes. On 16 August 1947, the maiden flight of the aircraft, which had received the designation DHC-2 Beaver , took place. In April 1948,

6868-558: The era. The prototype, serial number 1, CF-AYO, was designated the Norseman Mk.I . The next four aircraft (serial numbers 2, 3, 4 and 5) were Norseman Mk.IIIs . CF-AZA went to MacKenzie Air Service, Edmonton, Alberta , CF-AZE to Prospector Airways, Clarkson, Ontario, CF-AZS to Starrat Airways, Hudson, Ontario, and CF-BZM to Mackenzie Air Service, as CF-BAM . Several additional aircraft were to have been Mk.IIIs but were completed as Mk.IVs. CF-BAU , serial number 6, had minor changes that were required for it to be certified, and had

6969-431: The feathering process or the feathering process may be automatic. Accidental feathering is dangerous and can result in an aerodynamic stall ; as seen for example with Yeti Airlines Flight 691 which crashed during approach due to accidental feathering. The propellers on some aircraft can operate with a negative blade pitch angle, and thus reverse the thrust from the propeller. This is known as Beta Pitch. Reverse thrust

7070-635: The filming of " Captains of the Clouds " starring James Cagney . Principal aerial photography took place near North Bay, Ontario with CF-AYO carrying temporary registration "CF-HGO." CF-AYO was lost in a crash in Algonquin Park in 1952. Its wreckage currently is on display at the Canadian Bushplane Heritage Centre . Almost immediately, the Norseman proved itself to be a rugged, reliable workhorse with steady sales for

7171-684: The first production aircraft was delivered to the Ontario Department of Lands and Forests . A Royal New Zealand Air Force (RNZAF) Beaver played a supporting role in Sir Edmund Hillary 's famous 1958 Commonwealth Trans-Antarctic Expedition to the South Pole . In addition to its use in civilian operations, the Beaver has been widely adopted by armed forces as a utility aircraft . The United States Army purchased several hundred aircraft; nine DHC-2s are still in service with

7272-463: The front was a tractor . Later the term 'pusher' became adopted for the rear-mounted device in contrast to the tractor configuration and both became referred to as 'propellers' or 'airscrews'. The understanding of low speed propeller aerodynamics was fairly complete by the 1920s, but later requirements to handle more power in a smaller diameter have made the problem more complex. Propeller research for National Advisory Committee for Aeronautics (NACA)

7373-574: The fuselage – clockwise on the left engine and counterclockwise on the right – however, there are exceptions (especially during World War II ) such as the P-38 Lightning which turned "outwards" (counterclockwise on the left engine and clockwise on the right) away from the fuselage from the WW II years, and the Airbus A400 whose inboard and outboard engines turn in opposite directions even on

7474-464: 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

7575-414: The hub would have a negative AOA while the blade tip would be stalled. There have been efforts to develop propellers and propfans for aircraft at high subsonic speeds. The 'fix' is similar to that of transonic wing design. Thin blade sections are used and the blades are swept back in a scimitar shape ( scimitar propeller ) in a manner similar to wing sweepback, so as to delay the onset of shockwaves as

7676-519: The ideas inherent to rotary wing aircraft. Designs similar to the Chinese helicopter toy appeared in Renaissance paintings and other works. It was not until the early 1480s, when Leonardo da Vinci created a design for a machine that could be described as an "aerial screw" , that any recorded advancement was made towards vertical flight. His notes suggested that he built small flying models, but there were no indications for any provision to stop

7777-419: The legs secured with two bolts each to allow the alternate arrangement of floats or skis. The tail could be fitted with a wheel or skid. The first Norseman, powered by a Wright R-975 -E3 Whirlwind, was flight tested on floats on November 14, 1935, and was sold and delivered to Dominion Skyways Ltd. on January 18, 1936, registered as "CF-AYO" and named “Arcturus." In summer 1941, Warner Brothers leased CF-AYO for

7878-400: The length of the blades. This was necessary to maintain a more uniform angle of attack of the blade along its length. Their original propeller blades had an efficiency of about 82%, compared to 90% for a modern (2010) small general aviation propeller, the 3-blade McCauley used on a Beechcraft Bonanza aircraft. Roper quotes 90% for a propeller for a human-powered aircraft. Mahogany was

7979-641: The loaded weight. Deliveries began mid-1942, with the US military eventually ordered 749 Norseman Mk.IVs as the C-64A (later UC-64A ). Throughout the Second World War, the USAAF Norseman aircraft were used in North America (primarily Alaska) as well as other in theaters of war, including Europe. Three UC-64As were used by the US Navy under the designation JA-1 . Six C-64B floatplanes were used by

8080-432: The other wing to balance out the torque and p-factor effects. They are sometimes referred to as "handed" propellers since there are left hand and right hand versions of each prop. Generally, the propellers on both engines of most conventional twin-engined aircraft spin clockwise (as viewed from the rear of the aircraft). To eliminate the critical engine problem, counter-rotating propellers usually turn "inwards" towards

8181-417: The pilot to pull the propeller control back to disengage the high-pitch stop pins before the engine reaches idle RPM . Turboprop control systems usually use a negative torque sensor in the reduction gearbox, which moves the blades toward feather when the engine is no longer providing power to the propeller. Depending on design, the pilot may have to push a button to override the high-pitch stops and complete

8282-484: The power source's driveshaft either directly or through reduction gearing . Propellers can be made from wood, metal or composite materials . Propellers are most suitable for use at subsonic airspeeds generally below about 480 mph (770 km/h), although supersonic speeds were achieved in the McDonnell XF-88B experimental propeller-equipped aircraft. Supersonic tip-speeds are used in some aircraft like

8383-561: The propeller blades, giving maximum efficiency throughout the flight regime. This reduces fuel usage. Only by maximising propeller efficiency at high speeds can the highest possible speed be achieved. Effective angle of attack decreases as airspeed increases, so a coarser pitch is required at high airspeeds. The requirement for pitch variation is shown by the propeller performance during the Schneider Trophy competition in 1931. The Fairey Aviation Company fixed-pitch propeller used

8484-426: 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

8585-424: The rotor from making the craft rotate. As scientific knowledge increased and became more accepted, man continued to pursue the idea of vertical flight. Many of these later models and machines would more closely resemble the ancient bamboo flying top with spinning wings, rather than Leonardo's screw. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by

8686-411: The same force is expressed slightly differently in terms of thrust and torque since the required output of the propeller is thrust. Thrust and torque are the basis of the definition for the efficiency of the propeller as shown below. The advance ratio of a propeller is similar to the angle of attack of a wing. A propeller's efficiency is determined by Propellers are similar in aerofoil section to

8787-410: The same wing. A contra-rotating propeller or contra-prop places two counter-rotating propellers on concentric drive shafts so that one sits immediately 'downstream' of the other propeller. This provides the benefits of counter-rotating propellers for a single powerplant. The forward propeller provides the majority of the thrust, while the rear propeller also recovers energy lost in the swirling motion of

8888-399: The type as being "arguably the best bush plane ever built". The Beaver was designed to operate in all seasons and the majority of weather conditions; a large proportion were also equipped with floats for buoyancy in water; it reportedly possesses favourable performance characteristics for a floatplane . As a result of its favourable characteristics as a hard working and productive aircraft,

8989-425: 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

9090-481: 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

9191-445: The wood preferred for propellers through World War I , but wartime shortages encouraged use of walnut , oak , cherry and ash . Alberto Santos Dumont was another early pioneer, having designed propellers before the Wright Brothers for his airships . He applied the knowledge he gained from experiences with airships to make a propeller with a steel shaft and aluminium blades for his 14 bis biplane in 1906. Some of his designs used

9292-546: Was a passenger on a UC-64A Norseman (s/n 44-70285) flown by F/O John R. S. Morgan which disappeared over the English Channel on December 15, 1944, possibly due being struck by bombs jettisoned from RAF Lancasters after an aborted raid. Another Norseman crashed into King Alfred's Tower , a 50 m (160 ft) tall Stourhead estate folly in Somerset, England, killing all five air crew in 1944. Postwar,

9393-767: Was commonly used for conducting search and rescue missions. For some decades, the United States Navy has operated a pair of 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 for the towing of gliders . In recent years, growing numbers of the type have been used within the leisure industry, being used for pleasure flight and as lifting platforms for skydiving and aerial film activities. The DHC-2 Beaver has been used by skydiving operators due to its good climb rate. When fitted with

9494-408: Was delivered to the Ontario Department of Lands and Forests , who had been a design partner. 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

9595-407: Was designed to be all-metal (unlike older designs, like the famous 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

9696-757: Was destroyed in a hangar fire in September 1951. In 1953, Noorduyn headed a group of investors who bought back the jigs and equipment from Canada Car and Foundry and started a new company called Noorduyn Norseman Aircraft Ltd. Bob Noorduyn became ill and died at his home in South Burlington, Vermont, on 22 February 1959. The company continued to provide support for operating Norseman aircraft and built three new Mk.Vs before selling its assets in 1982 to Norco Associates. Norco provided support services only, as Norseman aircraft manufacture wasn't seen as being likely to be profitable. The last Noorduyn Norseman built

9797-616: Was directed by William F. Durand from 1916. Parameters measured included propeller efficiency, thrust developed, and power absorbed. While a propeller may be tested in a wind tunnel , its performance in free-flight might differ. At the Langley Memorial Aeronautical Laboratory , E. P. Leslie used Vought VE-7s with Wright E-4 engines for data on free-flight, while Durand used reduced size, with similar shape, for wind tunnel data. Their results were published in 1926 as NACA report #220. Lowry quotes

9898-447: Was partially stalled on take-off and up to 160 mph (260 km/h) on its way up to a top speed of 407.5 mph (655.8 km/h). The very wide speed range was achieved because some of the usual requirements for aircraft performance did not apply. There was no compromise on top-speed efficiency, the take-off distance was not restricted to available runway length and there was no climb requirement. The variable pitch blades used on

9999-414: Was purchased by Viking Air of Victoria, British Columbia , Canada, which manufactures replacement parts for most of the early de Havilland line. The company markets and sells the remanufactured DHC-2T Turbo Beaver, an improved variant of the aircraft which has been upgraded with a 680 shp (510 kW) PT6A-34, which enables an increased maximum gross takeoff weight of 6,000 lb (2,700 kg) and

10100-517: Was reorganized in 1935, as Noorduyn Aviation. Noorduyn's ideal bush plane was a high-wing monoplane airframe to facilitate loading and unloading passengers and cargo at seaplane docks, where the high wing provided the best clearance from docks and seaplane ramp fencing, and least opportunity for damage, and from conventional airports, with a structure that could be easily repaired in the bush. Noorduyn designed it to have interchangeable wheel, ski or twin-float landing gear. Unlike most aircraft designs,

10201-470: Was sold to a commercial customer on January 19, 1959. 903 Norseman Mk.I to Mk.V were produced and delivered to commercial and military customers. There are currently 42 Norseman aircraft on the active Canadian aircraft registry and 9 active in the United States. The number in use worldwide is not known. In recognition of the Norseman's role in serving northern Canada, the town of Red Lake, Ontario ,

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