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97-490: The Vickers Viscount is a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs . A design requirement from the Brabazon Committee , it entered service in 1953 and was the first turboprop-powered airliner. The Viscount was well received by the public for its cabin conditions, which included pressurisation , reductions in vibration and noise, and panoramic windows. It became one of
194-400: A Pratt & Whitney Canada PT6 , and an under-speed governor on a Honeywell TPE331 . The turboprop is also distinguished from other kinds of turbine engine in that the fuel control unit is connected to the governor to help dictate power. To make the engine more compact, reverse airflow can be used. On a reverse-flow turboprop engine, the compressor intake is at the aft of the engine, and
291-424: A propelling nozzle . Air enters the intake and is compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts . The hot combustion gases expand through the turbine stages, generating power at the point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator . The gases are then exhausted from
388-606: A 700 could carry a 13,000-lb payload from Chicago to New York in 2 hours 45 minutes against a 10-mph headwind, burning 6395 lb of fuel. In the field of intercity transports employing the propeller turbine, the Vickers Viscount Model 700 appears to be considerably superior to anything else in its class. [It has] exceptionally fine flying qualities and is a most comfortable vehicle in which to travel. John Watkins, Chief Technical Officer of Trans Australia Airlines . All production Viscounts were powered by
485-520: A bombing raid. In 1941, the engine was abandoned due to war, and the factory converted to conventional engine production. The first mention of turboprop engines in the general public press was in the February 1944 issue of the British aviation publication Flight , which included a detailed cutaway drawing of what a possible future turboprop engine could look like. The drawing was very close to what
582-408: A development aircraft for the type for several years. In late August 1950, BEA placed an order for 20 aircraft; further orders came in the following year from operators such as Air France , Aer Lingus , and Misrair . In 1953, the basic cost given for a Viscount was £235,000. One reporter, after travelling on an Air France Viscount, wrote in 1953: "Noise level was less than that of piston engines. It
679-585: A dozen Viscounts, and purchased later turboprop aircraft such as the Fokker F27 Friendship ; It later transitioned to jet aircraft as passenger demand outgrew the capacity of the Viscounts. To compete with its rival TAA, another Australian airline, Ansett-ANA also procured its own small Viscount fleet; the Viscount allowed Ansett to set out a faster and superior service than the larger TAA for
776-442: A governor, and overspeed governor, and a fuel-topping governor. The governor works in much the same way a reciprocating engine propeller governor works, though a turboprop governor may incorporate beta control valve or beta lift rod for beta operation and is typically located in the 12 o'clock position. There are also other governors that are included in addition depending on the model, such as an overspeed and fuel topping governor on
873-410: A mode typically consisting of zero to negative thrust, is used for all ground operations aside from takeoff. The Beta mode is further broken down into 2 additional modes, Beta for taxi and Beta plus power. Beta for taxi as the name implies is used for taxi operations and consists of all pitch ranges from the lowest alpha range pitch, all the way down to zero pitch, producing very little to zero-thrust and
970-561: A new allocation granted – in most cases this is from the new country's new ITU allocation, but neither is it uncommon for the new country to be allocated a subset of their former colonial power's allocation. For example, after partition in 1947, India retained the VT designation it had received as part of the British Empire's Vx series allocation, while Pakistan adopted the AP designation from
1067-565: A number suffix rather than letters, like the United States (N), South Korea (HL), and Japan (JA), the prefix and suffix are connected without a dash. Aircraft flying privately usually use their registration as their radio callsign , but many aircraft flying in commercial operations (especially charter, cargo, and airlines) use the ICAO airline designator or a company callsign. Some countries will permit an aircraft that will not be flown into
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#17327727273201164-720: A single letter prefix. Smaller countries had to share a single letter prefix, but were allocated exclusive use of the first letter of the suffix. This was modified by agreement by the International Bureau at Berne and published on April 23, 1913. Although initial allocations were not specifically for aircraft but for any radio user, the International Air Navigation Convention held in Paris in 1919 ( Paris Convention of 1919 ) made allocations specifically for aircraft registrations, based on
1261-581: A small amount of air by a large degree, a low disc loading (thrust per unit disc area) increases the aircraft's energy efficiency , and this reduces the fuel use. Propellers work well until the flight speed of the aircraft is high enough that the airflow past the blade tips reaches the speed of sound. Beyond that speed, the proportion of the power that drives the propeller that is converted to propeller thrust falls dramatically. For this reason turboprop engines are not commonly used on aircraft that fly faster than 0.6–0.7 Mach , with some exceptions such as
1358-591: A test-bed not intended for production. It first flew on 20 September 1945. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Clyde , the first turboprop engine to receive a type certificate for military and civil use, and the Dart , which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years. The Dart-powered Vickers Viscount
1455-489: Is coupled to the turbine through a reduction gear that converts the high RPM /low torque output to low RPM/high torque. This can be of two primary designs, free-turbine and fixed. A free-turbine turboshaft found on the Pratt & Whitney Canada PT6 , where the gas generator is not connected to the propeller. This allows for propeller strike or similar damage to occur without damaging the gas generator and allowing for only
1552-407: Is that it can also be used to generate reverse thrust to reduce stopping distance on the runway. Additionally, in the event of an engine failure, the propeller can be feathered , thus minimizing the drag of the non-functioning propeller. While the power turbine may be integral with the gas generator section, many turboprops today feature a free power turbine on a separate coaxial shaft. This enables
1649-421: Is typically accessed by moving the power lever to a beta for taxi range. Beta plus power is a reverse range and produces negative thrust, often used for landing on short runways where the aircraft would need to rapidly slow down, as well as backing operations and is accessed by moving the power lever below the beta for taxi range. Due to the pilot not being able to see out of the rear of the aircraft for backing and
1746-639: The Armstrong Siddeley Mamba , which the government specified for the two prototypes. The choice of the Mamba engine increased the weight, but Vickers made sure the engine nacelle would fit either the Mamba or Dart. While the Dart progressed better in development, the government asked in August 1947 for the second prototype to be Dart-powered. The second prototype was designated the 630 and was named as
1843-499: The Cocos (Keeling) Islands to Melbourne's Essendon Airport in 10 hours 16 minutes (343.8 mph). Trans Australia Airlines (TAA) received its first Viscount in 1954, and the aircraft quickly proved profitable, leading to additional orders. The Viscount proved to be an invaluable aircraft for TAA, aviation author John Gunn stating, "TAA had achieved dominance on Australia's trunk routes with its turboprop Viscounts". TAA procured over
1940-546: The Democratic Republic of the Congo . Data from British Civil Aircraft since 1919 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Turboprop A turboprop is a turbine engine that drives an aircraft propeller . A turboprop consists of an intake , reduction gearbox , compressor , combustor , turbine , and
2037-634: The P-3 Orion , and the C-130 Hercules military transport aircraft. The first turbine-powered, shaft-driven helicopter was the Kaman K-225 , a development of Charles Kaman 's K-125 synchropter , which used a Boeing T50 turboshaft engine to power it on 11 December 1951. December 1963 saw the first delivery of Pratt & Whitney Canada's PT6 turboprop engine for the then Beechcraft 87, soon to become Beechcraft King Air . 1964 saw
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#17327727273202134-841: The Piper Meridian , Socata TBM , Pilatus PC-12 , Piaggio P.180 Avanti , Beechcraft King Air and Super King Air . In April 2017, there were 14,311 business turboprops in the worldwide fleet. Between 2012 and 2016, the ATSB observed 417 events with turboprop aircraft, 83 per year, over 1.4 million flight hours: 2.2 per 10,000 hours. Three were "high risk" involving engine malfunction and unplanned landing in single‑engine Cessna 208 Caravans , four "medium risk" and 96% "low risk". Two occurrences resulted in minor injuries due to engine malfunction and terrain collision in agricultural aircraft and five accidents involved aerial work: four in agriculture and one in an air ambulance . Jane's All
2231-618: The Special Administrative Regions of the People's Republic of China , Hong Kong and Macau , both of which were returned to PRC control from Britain in 1997 and Portugal in 1999 respectively. Hong Kong's prefix of VR-H and Macau's of CS-M, both subdivisions of their colonial powers' allocations, were replaced by China's B- prefix without the registration mark being extended, leaving aircraft from both SARs with registration marks of only four characters, as opposed to
2328-614: The Tupolev Tu-114 can reach 470 kn (870 km/h; 540 mph). Large military aircraft , like the Tupolev Tu-95 , and civil aircraft , such as the Lockheed L-188 Electra , were also turboprop powered. The Airbus A400M is powered by four Europrop TP400 engines, which are the second most powerful turboprop engines ever produced, after the 11 MW (15,000 hp) Kuznetsov NK-12 . In 2017,
2425-403: The Tupolev Tu-95 . However, propfan engines, which are very similar to turboprop engines, can cruise at flight speeds approaching 0.75 Mach. To maintain propeller efficiency across a wide range of airspeeds, turboprops use constant-speed (variable-pitch) propellers. The blades of a constant-speed propeller increase their pitch as aircraft speed increases. Another benefit of this type of propeller
2522-425: The 1913 callsign list. The agreement stipulated that the nationality marks were to be followed by a hyphen then a group of four letters that must include a vowel (and for the convention Y was considered to be a vowel). This system operated until the adoption of the revised system in 1928. The International Radiotelegraph Convention at Washington in 1927 revised the list of markings. These were adopted from 1928 and are
2619-406: The 700. The fuselage was lengthened 3 ft 10 in (1.17 m) and the rear pressure bulkhead was moved aft 5 ft 5 in (1.65 m), allowing more passengers to be carried. The 800s (excepting the 806s) were powered by the Dart 510. The third type of Viscount was the 810. It was the same size as the 800s, but was powered with R.Da. 7/1 Mk 225 or Mk 530 Darts. With the greater power,
2716-465: The 810 was faster and longer ranged than the 800. Proposed type 740, 850, and 870 Viscounts never left the drawing board. The Viscount's good performance and popularity with customers encouraged Vickers to privately finance and develop an enlarged and re-engined variant of the Viscount, later designated as the Vickers Vanguard . The Vanguard drew extensively from the knowledge and design of
2813-478: The Chicago Convention, has an NAA whose functions include the registration of civil aircraft . An aircraft can only be registered once, in one jurisdiction, at a time. The NAA allocates a unique alphanumeric string to identify the aircraft, which also indicates the nationality (i.e., country of registration ) of the aircraft, and provides a legal document called a Certificate of Registration , one of
2910-521: The Rolls-Royce Dart turboprop; from its initial 800 hp, and then 1,000 hp and higher, Rolls-Royce extensively developed the Dart engine, due to its popularity and use on the Viscount and several later aircraft. One key model was the Dart 506 engine, with better fuel efficiency than earlier models, allowing airline Viscounts to fly longer routes, with more payload. With the availability of more powerful engines, Vickers continued to develop
3007-660: The Ryan NYP aircraft flown by Charles Lindbergh as the Spirit of St. Louis was registered in the experimental category. There is a unique overlap in the United States with aircraft having a single number followed by two letters and radio call signs issued by the Federal Communications Commission to Amateur Radio operators holding the Amateur Extra class license. For example, N4YZ is, on
Vickers Viscount - Misplaced Pages Continue
3104-533: The Soviet Union had the technology to create the airframe for a jet-powered strategic bomber comparable to Boeing's B-52 Stratofortress , they instead produced the Tupolev Tu-95 Bear, powered with four Kuznetsov NK-12 turboprops, mated to eight contra-rotating propellers (two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of
3201-577: The Type 700. Meanwhile, the first prototype Type 630 was awarded a restricted Certificate of Airworthiness on 15 September 1949, followed by a full certificate on 27 July 1950, which allowed the aircraft to be placed into trial service with BEA on 29 July to familiarise the pilots and ground crew with the new aircraft. It flew scheduled flights between London and Paris, and London and Edinburgh until 23 August 1950. The 29 July 1950 flight between Northolt and Paris – Le Bourget Airport with 14 paying passengers
3298-514: The US government imposed its embargo on Cuba in 1962, Cubana decided to sell all of its Viscounts. They were replaced by Soviet-built turboprop aircraft. South African Airways (SAA) was another major operator of the Viscount; by January 1959, it was operating on all of SAA's domestic routes. In 1961, SAA had seven Viscounts, and acquired a further aircraft from Cuba in the following year. In 1965, SAA began receiving Boeing 727s , which had been selected
3395-618: The United Kingdom) either because of personal or political reasons, or because they fear spurious lawsuits and potential arrest of the aircraft. The first use of aircraft registrations was based on the radio callsigns allocated at the London International Radiotelegraphic Conference in 1913. The format was a single letter prefix followed by four other letters (like A-BCDE). The major nations operating aircraft at that time were allocated
3492-475: The United States Department of Homeland Security) are assigned civil registrations. Although each aircraft registration identifier is unique, some countries allow it to be re-used when the aircraft has been sold, destroyed or retired. For example, N3794N is assigned to a Mooney M20F . It had been previously assigned to a Beechcraft Bonanza (specifically, the aircraft in which Buddy Holly
3589-499: The Viscount 700 prototype G-AMAV achieved the fastest time (40 hours 41 minutes flying time) in the transport section of the 12,367 mi (19,903 km) air race from London to Christchurch , New Zealand. The aircraft averaged 320 mph (520 km/h) in the event, crossing the finish line nine hours ahead of its closest rival, a Douglas DC-6 A of KLM , with the latter winning on handicap. En route , equipped with extra fuel tanks, it flew 3,530 mi (5,680 km) nonstop from
3686-594: The Viscount became the mainstay of the route between Johannesburg in South Africa, Salisbury (now renamed Harare) in modern-day Zimbabwe , and London, England. CAA had enough Viscounts to entirely replace its Viking fleet and to occasionally lease them to other operators. More Viscounts were purchased by CAA right up until 1965, when CAA announced its intention to procure the British Aircraft Corporation 's jet-powered BAC 1-11 successor as
3783-666: The Viscount generated considerable interest from airlines and industry figures across the United States, including American aviation pioneer Howard Hughes , who purchased 15 Viscounts immediately after personally flying one. US Capital Airlines became an important operator of the Type 700 Viscount, using it heavily throughout the eastern US routes; in 1958, Capital reportedly had accumulated over 350,000 flight hours on its Viscounts, more than any other operator. Continental Airlines and Northeast Airlines also became US Viscount operators. The first airline in Latin America to operate
3880-402: The Viscount project. Never having flown other than piston-engined aircraft I was tremendously impressed with the smoothness of the four Dart turboprop engines. As I sat in the cabin, a coin was balanced on its edge on the table... Test Pilot Joseph Summers , commenting on flight characteristics of the Viscount. The prototype Type 630, registered G-AHRF , made its maiden flight from
3977-470: The Viscount was Cubana de Aviación . Cubana's −755D Viscounts, delivered in 1956, were placed on the Havana -Miami and Varadero -Miami routes, and were successful at raising Cubana's market share on these routes. During the 1958 Cuban elections, a Cubana Viscount was hijacked by gunmen aligned with the 26th of July Movement ; the aircraft crash-landed in the sea, reportedly killing 17 of the 20 occupants. When
Vickers Viscount - Misplaced Pages Continue
4074-584: The Viscount with Britain directly. The last batch of six aircraft built was for the Chinese CAAC Airlines , which was delivered during 1964; at the end of production. 445 Viscounts had been manufactured. Many Viscounts were refurbished and saw new service with African operators; sales of these second-hand aircraft continued into the 1990s. The last airworthy Viscount, 9Q-COD, is believed to have been flown last in January 2009 for Global Airways in
4171-788: The Viscount with a newer turboprop aircraft, the Hawker Siddeley HS 748 . On 18 April 1996, British World Airlines conducted the last Viscount passenger service in Britain, exactly 46 years after BEA's inaugural flight; on board the flight were Sir George Edwards and Sir Peter Masefield . In late 1960, the People's Republic of China had begun negotiations with Vickers for as many as 40 Viscounts, but negotiations were protracted due to political tensions. At this point, China sought arrangements to purchase Viscounts second-hand from existing operators, and later achieved successive deals regarding
4268-424: The Viscount's design. Later models could carry more passengers and had fewer load limitations. Three basic versions of the Viscount were built. The first production version was the Type 700 powered by R.Da.3 Dart 505 and later R.Da.3 Dart 506s. A subvariant was the type 700Ds powered by R.D.a Dart 510s. The second version was the Type 800, which was shorter in range and had a higher passenger capacity aircraft than
4365-515: The Viscount, and maintained its advantage of lower operating costs over jet airliners, but its disadvantage in being slower became critical as jets became more available. Regular passenger flights were launched by BEA on 18 April 1953, the world's first scheduled turboprop airline service. BEA became a large user of the Viscount, as well the rival Handley Page Dart Herald ; by mid-1958, BEA's Viscount fleet had carried over 2.75 million passengers over 200,000 flight hours. Following BEA's launch of
4462-464: The Viscount. The first prototype already under construction was converted to the Dart as a 630, as well. The resulting Vickers Type 630 design was completed at Brooklands by chief designer Rex Pierson and his staff in 1945, a 32-seat airliner powered by four Dart engines for a cruising speed of 275 mph (443 km/h). An order for two prototypes was placed in March 1946, and construction started in
4559-459: The Viscount... it was quite likely that the smaller version would have gone into production... It was in a sense BEA's lack of enthusiasm for the [Type] 630 which made possible the [Viscount's] success." Early flight trials, however, showed the qualities of a turboprop, resulting in a February 1949 order from the Ministry of Supply for a prototype of a stretched version with more powerful engines,
4656-495: The World's Aircraft . 2005–2006. Aircraft registration An aircraft registration is a code unique to a single aircraft, required by international convention to be marked on the exterior of every civil aircraft. The registration indicates the aircraft's country of registration, and functions much like an automobile license plate or a ship registration. This code must also appear in its Certificate of Registration, issued by
4753-420: The additional expansion in the turbine system, the residual energy in the exhaust jet is low. Consequently, the exhaust jet produces about 10% of the total thrust. A higher proportion of the thrust comes from the propeller at low speeds and less at higher speeds. Turboprops have bypass ratios of 50–100, although the propulsion airflow is less clearly defined for propellers than for fans. The propeller
4850-583: The aircraft carry 32 passengers, instead, but remained otherwise similar. The first design in June 1945 was based on the Viking with four turboprop engines and 24 seats and designated the VC-2 or Type 453. Later, a double-bubble fuselage was proposed to give extra underfloor cargo space. Neither was pressurised, but the designers soon realised that for economical operation, an altitude above 20,000 ft (6,100 m)
4947-404: The aircraft to be registered in the carrier's home country (either because it does not have sufficient regulation governing civil aviation , or because it feels the courts in that country would not cooperate fully if it needed to enforce any security interest over the aircraft), and the carrier is reluctant to have the aircraft registered in the financier's jurisdiction (often the United States or
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#17327727273205044-522: The airspace of another country to display the registration with the country prefix omitted - for example, gliders registered in Australia commonly display only the three-letter unique mark, without the "VH-" national prefix. Some countries also operate a separate registry system, or use a separate group of unique marks, for gliders, ultralights, and/or other less-common types of aircraft. For example, Germany and Switzerland both use lettered suffixes (in
5141-414: The amount of debris reverse stirs up, manufacturers will often limit the speeds beta plus power may be used and restrict its use on unimproved runways. Feathering of these propellers is performed by the propeller control lever. The constant-speed propeller is distinguished from the reciprocating engine constant-speed propeller by the control system. The turboprop system consists of 3 propeller governors ,
5238-617: The basis of the currently used registrations. The markings have been amended and added to over the years, and the allocations and standards have since 1947 been managed by the International Civil Aviation Organization (ICAO). Article 20 of the Convention on International Civil Aviation (Chicago Convention), signed in 1944, requires that all aircraft engaged in international air navigation bears its appropriate nationality and registration marks. Upon
5335-521: The combinations that could be used: An older aircraft (registered before 31 December 1948) may have a second letter in its identifier, identifying the category of aircraft. This additional letter is not actually part of the aircraft identification (e.g. NC12345 is the same registration as N12345). Aircraft category letters have not been included on any registration numbers issued since 1 January 1949, but they still appear on antique aircraft for authenticity purposes. The categories were: For example, N-X-211,
5432-583: The committee and Vickers' chief designer, Rex Pierson , Vickers advocated turboprop power. The committee was not convinced and split the specification into two types, the Type IIA using piston power, which led to the Airspeed Ambassador , and the turboprop-powered Type IIB, which Vickers was selected to develop in April 1945. British European Airways (BEA) was involved in the design and asked that
5529-524: The company's Foxwarren Experimental Department. Originally named Viceroy after the viceroy of India, Lord Louis Mountbatten , the aircraft was renamed Viscount following India's independence in 1947. Work took place on replacing the Darts with the Mamba, but this was dropped by the time the prototypes were reaching completion. After Pierson's death in 1948, George Edwards (later Sir George Edwards) took over as chief designer and assumed all technical control over
5626-533: The completion of the necessary procedures, the aircraft receives its unique "registration", which must be displayed prominently on the aircraft. Annex 7 to the Chicago Convention describes the definitions, location, and measurement of nationality and registration marks. The aircraft registration is made up of a prefix selected from the country's callsign prefix allocated by the International Telecommunication Union (ITU) (making
5723-581: The documents which must be carried when the aircraft is in operation. The registration identifier must be displayed prominently on the aircraft. Most countries also require the registration identifier to be imprinted on a permanent fireproof plate mounted on the fuselage in case of a post-fire/post-crash aircraft accident investigation . Most nations' military aircraft typically use tail codes and serial numbers. Military aircraft most often are not assigned civil registration codes. However, government-owned non-military civil aircraft (for example, aircraft of
5820-473: The end of 1953, the order book had risen to 90, and 160 by the end of the following year. Vickers was able to quickly respond to the new orders, as it had gambled on such orders emerging and early on the decision had been taken to commit to a high production rate at the company's own risk. In 1957, the Vickers production line was producing the Viscount at a rate of one aircraft every three days. In October 1953,
5917-407: The exhaust is situated forward, reducing the distance between the turbine and the propeller. Unlike the small-diameter fans used in turbofan engines, the propeller has a large diameter that lets it accelerate a large volume of air. This permits a lower airstream velocity for a given amount of thrust. Since it is more efficient at low speeds to accelerate a large amount of air by a small degree than
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#17327727273206014-499: The first jet aircraft and comparable to jet cruising speeds for most missions. The Bear would serve as their most successful long-range combat and surveillance aircraft and symbol of Soviet power projection through to the end of the 20th century. The USA used turboprop engines with contra-rotating propellers, such as the Allison T40 , on some experimental aircraft during the 1950s. The T40-powered Convair R3Y Tradewind flying-boat
6111-590: The first Viscount was delivered to Canada in a large media event that included an improvised aerial display. TCA became a prolific operator of the type, placing multiple follow-up orders for additional Viscounts. By 1958, TCA had an operational fleet of 51 Viscounts. Aviation author Peter Pigott later wrote: "For TCA and Vickers, the Viscount was a public-relations coup. Passengers loved the quiet ride and panoramic windows. No other airline in North America flew turbo-prop airliners then, and no other British aircraft
6208-564: The first deliveries of the Garrett AiResearch TPE331 , (now owned by Honeywell Aerospace ) on the Mitsubishi MU-2 , making it the fastest turboprop aircraft for that year. In contrast to turbofans , turboprops are most efficient at flight speeds below 725 km/h (450 mph; 390 knots) because the jet velocity of the propeller (and exhaust) is relatively low. Modern turboprop airliners operate at nearly
6305-491: The first time. The Two Airlines Policy was formally established in 1952 by the Fifth Menzies Ministry. The policy took practical effect when Ansett purchased the failing Australian National Airways in 1957, resulting in it being the only competitor for the government-owned TAA. Unstated was the requirement for both airlines to have identical equipment. The first North American airline to use turboprop aircraft
6402-480: The form D-xxxx and HB-xxx respectively) for most forms of flight-craft but numbers (D-nnnn and HB-nnn) for unpowered gliders. Many other nations register gliders in subgroups beginning with the letter G, such as Norway with LN-Gxx and New Zealand with ZK-Gxx. In the United States , the registration number is commonly referred to as an "N" number, because all aircraft registered there have a number starting with
6499-441: The fuselage from 65 ft 5 in (19.94 m) to 74 ft 6 in (22.71 m) and meant an increased wingspan of 89 ft (27 m). The contract for the aircraft to Air Ministry specification C.16/46 was signed on 9 March 1946 and Vickers allocated the designation Type 609 and the name Viceroy . Although George Edwards had always favoured the 800 hp Rolls-Royce Dart other engines were considered, including
6596-465: The future Rolls-Royce Trent would look like. The first British turboprop engine was the Rolls-Royce RB.50 Trent , a converted Derwent II fitted with reduction gear and a Rotol 7 ft 11 in (2.41 m) five-bladed propeller. Two Trents were fitted to Gloster Meteor EE227 — the sole "Trent-Meteor" — which thus became the world's first turboprop-powered aircraft to fly, albeit as
6693-463: The grass airfield at Wisley on 16 July 1948, piloted by Joseph "Mutt" Summers , Vickers' chief test pilot . The design was considered too small and slow at 275 mph (443 km/h), making the per-passenger operating costs too high for regular service, and BEA had placed an order for 20 piston-engined Airspeed Ambassadors in 1947. Retrospectively commenting on Britain's aviation industry, Duncan Burn stated: "Had BEA committed itself to full support of
6790-419: The letter N. An alphanumeric system is used because of the large numbers of aircraft registered in the United States. An N-number begins with a run of one or more numeric digits, may end with one or two alphabetic letters, may only consist of one to five characters in total, and must start with a digit other than zero. In addition, N-numbers may not contain the letters I or O , due to their similarities with
6887-462: The long-term successor to the Viscount. BEA, and its nationalised successor British Airways (BA), vigorously operated the Viscount on Britain's domestic routes. In the 1980s, BA began withdrawing its ageing Viscount fleet; all BA Viscount operations in Scotland had ended in 1982. Former BA aircraft were often sold on to charter operators such as British Air Ferries . Some airlines chose to replace
6984-463: The most successful and profitable of the first postwar transport aircraft; 445 Viscounts were built for a range of international customers, including in North America. The Viscount was a response to the 1943 Brabazon Committee's proposed Type II design for a postwar, small, medium-range, pressurised aircraft to fly less-travelled routes, carrying 24 passengers up to 1,750 mi (2,816 km) at 200 mph (320 km/h). During discussions between
7081-671: The most widespread turboprop airliners in service were the ATR 42 / 72 (950 aircraft), Bombardier Q400 (506), De Havilland Canada Dash 8 -100/200/300 (374), Beechcraft 1900 (328), de Havilland Canada DHC-6 Twin Otter (270), Saab 340 (225). Less widespread and older airliners include the BAe Jetstream 31 , Embraer EMB 120 Brasilia , Fairchild Swearingen Metroliner , Dornier 328 , Saab 2000 , Xian MA60 , MA600 and MA700 , Fokker 27 and 50 . Turboprop business aircraft include
7178-480: The newly allocated ITU callsigns APA-ASZ. When this happens it is usually the case that aircraft will be re-registered into the new series retaining as much of the suffix as is possible. For example, when in 1929 the British Dominions at the time established their own aircraft registers, marks were reallocated as follows: Two oddities created by this reallocation process are the current formats used by
7275-405: The numerals 1 and 0 . Each alphabetic letter in the suffix can have one of 24 discrete values, while each numeric digit can be one of 10, except the first, which can take on only one of nine values. This yields a total of 915,399 possible registration numbers in the namespace , though certain combinations are reserved either for government use or for other special purposes. The following are
7372-587: The one hand, a Cessna 206 registered to a private individual in Melba, Idaho , while, on the other hand, is also issued to an Amateur Radio operator in North Carolina. Since an aircraft registration number is also used as its call sign, this means that two unrelated radio stations can have the same call sign. The impact of decolonisation and independence on aircraft registration schemes has varied from place to place. Most countries, upon independence, have had
7469-493: The power section (turbine and gearbox) to be removed and replaced in such an event, and also allows for less stress on the start during engine ground starts. Whereas a fixed shaft has the gearbox and gas generator connected, such as on the Honeywell TPE331 . The propeller itself is normally a constant-speed (variable pitch) propeller type similar to that used with larger aircraft reciprocating engines , except that
7566-413: The previous year as a jet-powered replacement for the Viscount. SAA sold its last Viscount to British Midland in the 1970s. Central African Airways (CAA) had been a traditional customer of Vickers, already operating a number of Vickers Vikings when it received its first Viscount on 25 April 1956. The introduction of the Viscount roughly coincided with the opening of a major airport at Salisbury , and
7663-534: The propeller to rotate freely, independent of compressor speed. Alan Arnold Griffith had published a paper on compressor design in 1926. Subsequent work at the Royal Aircraft Establishment investigated axial compressor-based designs that would drive a propeller. From 1929, Frank Whittle began work on centrifugal compressor-based designs that would use all the gas power produced by the engine for jet thrust. The world's first turboprop
7760-403: The propeller-control requirements are very different. Due to the turbine engine's slow response to power inputs, particularly at low speeds, the propeller has a greater range of selected travel in order to make rapid thrust changes, notably for taxi, reverse, and other ground operations. The propeller has 2 modes, Alpha and Beta. Alpha is the mode for all flight operations including takeoff. Beta,
7857-518: The registration a quick way of determining the country of origin) and the registration suffix. Depending on the country of registration, this suffix is a numeric or alphanumeric code, and consists of one to five characters. A supplement to Annex 7 provides an updated list of approved nationality and common marks used by various countries. While the Chicago convention sets out the country-specific prefixes used in registration marks, and makes provision for
7954-556: The relevant civil aviation authority (CAA). An aircraft can only have one registration, in one jurisdiction, though it is changeable over the life of the aircraft. In accordance with the Convention on International Civil Aviation (also known as the Chicago Convention), all civil aircraft must be registered with a civil aviation authority (CAA) using procedures set by each country. Every country, even those not party to
8051-592: The same speed as small regional jet airliners but burn two-thirds of the fuel per passenger. Compared to piston engines, their greater power-to-weight ratio (which allows for shorter takeoffs) and reliability can offset their higher initial cost, maintenance and fuel consumption. As jet fuel can be easier to obtain than avgas in remote areas, turboprop-powered aircraft like the Cessna Caravan and Quest Kodiak are used as bush airplanes . Turboprop engines are generally used on small subsonic aircraft, but
8148-415: The turbine. In contrast to a turbojet or turbofan , the engine's exhaust gases do not provide enough power to create significant thrust, since almost all of the engine's power is used to drive the propeller. Exhaust thrust in a turboprop is sacrificed in favor of shaft power, which is obtained by extracting additional power (beyond that necessary to drive the compressor) from turbine expansion. Owing to
8245-433: The type, multiple independent charter operators, such as British Eagle , were quick to adopt the Viscount into their fleets. During the 1960s, the Viscount formed the backbone of domestic air travel in Scotland. The early operational service of the Viscount quickly proved it to have significant performance advances over its rivals, and orders rapidly rose as a result; up to November 1952, only 42 aircraft had been ordered; by
8342-430: The ways they are used in international civil aviation and displayed on aircraft, individual countries also make further provision for their formats and the use of registration marks for intranational flight. When painted on the aircraft's fuselage, the prefix and suffix are usually separated by a dash (for example, YR-BMA). When entered in a flight plan , the dash is omitted (for example, YRBMA). In some countries that use
8439-433: Was Trans-Canada Air Lines (TCA), with a small fleet of Type 700 Viscounts. Initially, TCA was cautious of the Viscount due to the turboprop engine being a new technology, and a preference had existed for acquiring the piston-engined Convair CV-240 , instead; praise of the Viscount from pilots and a promise from Vickers to make any design changes desired by TCA persuaded it to procure the Viscount, instead. On 6 December 1954,
8536-662: Was killed ). An individual aircraft may be assigned different registrations during its existence. This can be because the aircraft changes ownership, jurisdiction of registration, or in some cases for vanity reasons. Most often, aircraft are registered in the jurisdiction in which the carrier is resident or based, and may enjoy preferential rights or privileges as a flag carrier for international operations. Carriers in emerging markets may be required to register aircraft in an offshore jurisdiction where they are leased or purchased but financed by banks in major onshore financial centres. The financing institution may be reluctant to allow
8633-457: Was a definite relief to be rid of the rough vibrations... The turboprop is an excellent shorthaul airplane and a definite crowd pleaser. The substitution of a lower constant-pitch noise and smoothness for the vibration, grunts, and groans of the piston engine gives the hesitant passenger a feeling of confidence." Viscount cabin windows were huge ellipses, 19 by 26 inches. Viscount operational costs were lower than many rival aircraft; Vickers projected
8730-592: Was bought by American airlines in such quantity." TCA operated the Viscount for two decades until Air Canada (TCA relabelled with a name equally at home in English and French), ended Viscount services in 1974. The type was replaced by the McDonnell Douglas DC-9 . Routine Flight (1955) featured the TCA introduction of the Viscount in this National Film Board of Canada documentary. TCA's procurement of
8827-573: Was designed by the Hungarian mechanical engineer György Jendrassik . Jendrassik published a turboprop idea in 1928, and on 12 March 1929 he patented his invention. In 1938, he built a small-scale (100 Hp; 74.6 kW) experimental gas turbine. The larger Jendrassik Cs-1 , with a predicted output of 1,000 bhp, was produced and tested at the Ganz Works in Budapest between 1937 and 1941. It
8924-501: Was needed. Thus, pressurisation was required. The decision for pressurisation resulted in the double-bubble and elliptical fuselage designs being abandoned. A circular cross-section variant was offered at the beginning of 1946. The resulting 28-seat VC-2 was financed by the Ministry of Supply with an order for two prototypes. Before the contract was signed, though, the government asked for the capacity to be increased to 32. This stretched
9021-467: Was of axial-flow design with 15 compressor and 7 turbine stages, annular combustion chamber. First run in 1940, combustion problems limited its output to 400 bhp. Two Jendrassik Cs-1s were the engines for the world's first turboprop aircraft – the Varga RMI-1 X/H . This was a Hungarian fighter-bomber of WWII which had one model completed, but before its first flight it was destroyed in
9118-714: Was operated by the U.S. Navy for a short time. The first American turboprop engine was the General Electric XT31 , first used in the experimental Consolidated Vultee XP-81 . The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power. The technology of Allison's earlier T38 design evolved into the Allison T56 , used to power the Lockheed Electra airliner, its military maritime patrol derivative
9215-690: Was the first scheduled airline flight by any turbine-powered aircraft. The second prototype Viscount, the Type 663 testbed, had two Rolls-Royce Tay turbojet engines, and first flew in RAF markings as serial VX217 at Wisley on 15 March 1950. It was demonstrated at the Farnborough SBAC Show in September and was later used in the development of powered controls for the Valiant bomber. It later
9312-527: Was the first turboprop aircraft of any kind to go into production and sold in large numbers. It was also the first four-engined turboprop. Its first flight was on 16 July 1948. The world's first single engined turboprop aircraft was the Armstrong Siddeley Mamba -powered Boulton Paul Balliol , which first flew on 24 March 1948. The Soviet Union built on German World War II turboprop preliminary design work by Junkers Motorenwerke, while BMW, Heinkel-Hirth and Daimler-Benz also worked on projected designs. While
9409-401: Was used as a test bed by Boulton Paul Ltd for the development of electronic flight-control systems. The designers then went back to the drawing board and the aircraft emerged as the larger Type 700 with up to 48 passengers (53 in some configurations), and a cruising speed of 308 mph (496 km/h). The new prototype G-AMAV first flew from Brooklands on 28 August 1950, and served as
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