Misplaced Pages

#483516

45-614: The F27 was developed during the early 1950s with the intent of producing a capable successor to the earlier piston engine -powered airliners that had become commonplace on the market, such as the Douglas DC-3 . A key innovation of the F27 was the adoption of the Rolls-Royce Dart turboprop engine, which produced substantially less vibration and noise which provided improved conditions for passengers; another major comfort feature

90-441: A crankshaft or by a swashplate or other suitable mechanism. A flywheel is often used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle. The more cylinders a reciprocating engine has, generally, the more vibration-free (smoothly) it can operate. The power of a reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between

135-459: A flywheel , the power from other pistons connected to the same shaft or (in a double acting cylinder ) by the same process acting on the other side of the piston. This is where the piston forms the smallest volume in the cylinder. In most types the expanded or " exhausted " gases are removed from the cylinder by this stroke . The exception is the Stirling engine , which repeatedly heats and cools

180-577: A piston engine , is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion . This article describes the common features of all types. The main types are: the internal combustion engine , used extensively in motor vehicles ; the steam engine , the mainstay of the Industrial Revolution ; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either

225-440: A spark-ignition (SI) engine , where the spark plug initiates the combustion; or a compression-ignition (CI) engine , where the air within the cylinder is compressed, thus heating it , so that the heated air ignites fuel that is injected then or earlier . There may be one or more pistons. Each piston is inside a cylinder , into which a gas is introduced, either already under pressure (e.g. steam engine ), or heated inside

270-597: A capacity of 1,820 L (64 cu ft), making a total capacity of 25,480 L (900 cu ft) for the largest versions. For piston engines, an engine's capacity is the engine displacement , in other words the volume swept by all the pistons of an engine in a single movement. It is generally measured in litres (l) or cubic inches (c.i.d., cu in, or in ) for larger engines, and cubic centimetres (abbreviated cc) for smaller engines. All else being equal, engines with greater capacities are more powerful and consumption of fuel increases accordingly (although this

315-469: A cylinder to drive a reciprocating engine in a local-pollution-free urban vehicle. Torpedoes may use a working gas produced by high test peroxide or Otto fuel II , which pressurize without combustion. The 230 kg (510 lb) Mark 46 torpedo , for example, can travel 11 km (6.8 mi) underwater at 74 km/h (46 mph) fuelled by Otto fuel without oxidant . Quantum heat engines are devices that generate power from heat that flows from

360-418: A dozen cylinders or more. Cylinder capacities may range from 10 cm or less in model engines up to thousands of liters in ships' engines. The compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The bore/stroke ratio

405-406: A hot to a cold reservoir. The mechanism of operation of the engine can be described by the laws of quantum mechanics . Quantum refrigerators are devices that consume power with the purpose to pump heat from a cold to a hot reservoir. In a reciprocating quantum heat engine, the working medium is a quantum system such as spin systems or a harmonic oscillator. The Carnot cycle and Otto cycle are

450-567: A large number of unusual varieties of piston engines that have various claimed advantages, many of which see little if any current use: Maritime reconnaissance Maritime patrol or maritime reconnaissance is the task of monitoring areas of water. Generally conducted by military and law enforcement agencies , maritime patrol is usually aimed at identifying human activities. Maritime patrol refers to active patrol of an area, as opposed to passive monitoring systems such as sound-detection fixtures or land-based spotters. A patrol consists of

495-486: A longer fatigue life, improved aerodynamics, and a lighter structure; Fokker became the first such company after de Havilland to employ such means. In 1953, the proposed airliner received the name Friendship . A total of four prototypes were produced, two of these being flyable aircraft that were used for the test flight programme and were paid for by the Netherlands Institute of Aircraft Development ;

SECTION 10

#1732787830484

540-651: A mixture of ATR 42 and ATR 72 aircraft by the end of 2009, the last of these aircraft were subsequently donated to the Hickory Aviation Museum . As of July 2010 a total of 65 F27s were in commercial service with almost 30 different airlines. By July 2013, only 25 Friendships remained in service, operated by 13 different airlines; most of these were F27-500s, with two -400s and a solitary -600 series aircraft in service. Italian cargo airline MiniLiner operated six F27s and Air Panama had four in its fleet. The United States Army Parachute Team has operated

585-572: A seal, and more heavily when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders usually measured in cubic centimetres (cm or cc) or litres (l) or (L) (US: liter). For example, for internal combustion engines, single and two-cylinder designs are common in smaller vehicles such as motorcycles , while automobiles typically have between four and eight, and locomotives and ships may have

630-484: A sequence of strokes that admit and remove gases to and from the cylinder. These operations are repeated cyclically and an engine is said to be 2-stroke , 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. The most common type is 4-stroke, which has following cycles. The reciprocating engine developed in Europe during the 18th century, first as the atmospheric engine then later as

675-428: A single C-31A Troopship for conducting its skydiving exhibitions since 1985. As of July 2018, 10 aircraft remain in service operated by 7 airlines. Finland Data from The Observers Book of Aircraft General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists Piston engine A reciprocating engine , also often known as

720-586: Is not to be confused with fuel efficiency , since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of 75 kW/L (1.65 hp/in ). Reciprocating engines that are powered by compressed air, steam or other hot gases are still used in some applications such as to drive many modern torpedoes or as pollution-free motive power. Most steam-driven applications use steam turbines , which are more efficient than piston engines. The French-designed FlowAIR vehicles use compressed air stored in

765-412: Is not true of every reciprocating engine), although power and fuel consumption are affected by many factors outside of engine displacement. Reciprocating engines can be characterized by their specific power , which is typically given in kilowatts per litre of engine displacement (in the U.S. also horsepower per cubic inch). The result offers an approximation of the peak power output of an engine. This

810-394: Is the fictitious pressure which would produce the same amount of net work that was produced during the power stroke cycle. This is shown by: where A p {\displaystyle A_{p}} is the total piston area of the engine, S {\displaystyle S} is the stroke length of the pistons, and V d {\displaystyle V_{d}}

855-459: Is the ratio of the diameter of the piston, or " bore ", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square". If it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line , in a V configuration , horizontally opposite each other, or radially around

900-425: Is the total displacement volume of the engine. Therefore: Whichever engine with the larger value of MEP produces more net work per cycle and performs more efficiently. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle. These are worked by cams, eccentrics or cranks driven by the shaft of the engine. Early designs used

945-423: Is then fed through one or more, increasingly larger bore cylinders successively, to extract power from the steam at increasingly lower pressures. These engines are called compound engines . Aside from looking at the power that the engine can produce, the mean effective pressure (MEP), can also be used in comparing the power output and performance of reciprocating engines of the same size. The mean effective pressure

SECTION 20

#1732787830484

990-452: The D slide valve but this has been largely superseded by piston valve or poppet valve designs. In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can often be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder . Internal combustion engines operate through

1035-420: The steam engine . These were followed by the Stirling engine and internal combustion engine in the 19th century. Today the most common form of reciprocating engine is the internal combustion engine running on the combustion of petrol , diesel , liquefied petroleum gas (LPG) or compressed natural gas (CNG) and used to power motor vehicles and engine power plants . One notable reciprocating engine from

1080-510: The DC-3, the F27 possessed superior levels of efficiency, enabling faster flight times, greater passenger comfort and a higher level of reliability. In 1960, the base purchase price for an RDa.6-powered F27 was £239,000. By the end of the production run for the Fokker F27 in 1987, a total of 592 units had been completed by Fokker (additionally, another 207 F-27s and FH-227s had been produced in

1125-655: The F27 was manufactured in the United States by the latter; Fairchild went on to independently develop a stretched version of the airliner, which was designated as the Fairchild FH-227 . During the 1980s, Fokker developed a modernised successor to the F27, the Fokker 50 , which eventually replaced it in production. In the aftermath of the Second World War , twin-engine all-metal monoplanes such as

1170-485: The F27 were developed and made available for commercial operators. Several military transport models were also produced. Fokker also chose to design a dedicated model of the F27 for conducting maritime reconnaissance missions. During 1952, Fokker established a relationship with the US aircraft manufacturer Fairchild , which was interested in the upcoming F27. In 1956, Fokker signed a licensing deal with Fairchild, under which

1215-571: The F27. The Fokker 50 ultimately replaced the F27 in production. In November 1958, the first production aircraft, an F27-100 model, was delivered to Irish airline Aer Lingus ; it performed its first revenue flight in the following month. Other early customers of the Friendship included Braathens SAFE and Luxair in Europe; New Zealand National Airways Corporation ; Trans Australia Airlines and its Australian competitors Ansett and East-West Airlines ; and Turkish Airlines . Initial sales for

1260-421: The US by Fairchild), more than any other western European civil turboprop airliner at the time. In later service, many aircraft have been modified from their original configurations for passenger service to perform cargo or express-package freighter duties instead. The last major cargo user of the F27 in the United States was FedEx Express , using it as a cargo "feeder" aircraft. These were retired and replaced by

1305-489: The World War II era was the 28-cylinder, 3,500  hp (2,600 kW) Pratt & Whitney R-4360 Wasp Major radial engine. It powered the last generation of large piston-engined planes before jet engines and turboprops took over from 1944 onward. It had a total engine capacity of 71.5 L (4,360 cu in), and a high power-to-weight ratio . The largest reciprocating engine in production at present, but not

1350-477: The crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic . Some designs have set the cylinders in motion around the shaft, such as the rotary engine . In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam. This

1395-430: The cylinder either by ignition of a fuel air mixture ( internal combustion engine ) or by contact with a hot heat exchanger in the cylinder ( Stirling engine ). The hot gases expand, pushing the piston to the bottom of the cylinder. This position is also known as the bottom dead center (BDC), or where the piston forms the largest volume in the cylinder. The piston is returned to the cylinder top (top dead center) (TDC) by

Fokker F27 Friendship - Misplaced Pages Continue

1440-458: The design team chose to incorporate various new technologies into the tentative design. Fokker evaluated several potential configurations for the airliner, including the use of Wright Cyclone radial engines , before finally settling upon a high- wing aircraft, which was furnished with a pair of Rolls-Royce Dart turboprop engines and a pressurised cabin which contained a total of 28 passengers. The Dart engine had already proven successful on

1485-633: The early 1980s, Fokker decided to develop a modernised successor to the F27 Friendship, designated as the F27 Mark 050 and marketed as the Fokker 50 . Although originating from the F27-500 airframe, the Fokker 50 was virtually a new aircraft, complete with Pratt & Whitney Canada engines and modern systems, which led to its general performance and passenger comfort being noticeably improved over

1530-481: The early models of the Vickers Viscount , while a high-mounted wing had been selected as it produced a higher lift coefficient than a lower counterpart, it also enabled easier ground loading due to a lower floor level and provided unfettered external views to passengers without any weight increase. In the aircraft's construction, Fokker used an innovative metal-to-metal bonding technique, Redux , resulting in

1575-604: The largest ever built, is the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine of 2006 built by Wärtsilä . It is used to power the largest modern container ships such as the Emma Mærsk . It is five stories high (13.5 m or 44 ft), 27 m (89 ft) long, and weighs over 2,300 metric tons (2,535 short tons ; 2,264 long tons ) in its largest 14 cylinders version producing more than 84.42 MW (113,209 bhp). Each cylinder has

1620-575: The latter was authorised to manufacture the F27 in the USA. On 12 April 1958, the first American-built aircraft conducted its first flight. Production of Fairchild built aircraft would continue until July 1973. Fairchild proceeded to independently develop a stretched version of the airliner, designated as the FH-227 . The majority of sales completed by Fairchild fell within the North American market. In

1665-488: The maximum number of passengers which could be carried to 32. These aircraft were also powered by the Dart Mk 528 engine, which was capable of generating greater thrust. Throughout the F27's production life, Fokker proceeded to adapt the design for various purposes and roles. Via modifications such as the adoption of improved engines, rearranged loading doors, elongated fuselages, and other changes, several different models of

1710-410: The ones most studied. The quantum versions obey the laws of thermodynamics . In addition, these models can justify the assumptions of endoreversible thermodynamics . A theoretical study has shown that it is possible and practical to build a reciprocating engine that is composed of a single oscillating atom. This is an area for future research and could have applications in nanotechnology . There are

1755-414: The other two prototypes were for static and fatigue testing. On 24 November 1955, the first prototype, registered PH-NIV , performed its maiden flight . The second prototype and initial production machines were 0.9 m (3 ft) longer than the first prototype in order to address a revealed tendency for slightly tail-heavy handling as well as to provide additional space for four more passengers, raising

1800-505: The same sealed quantity of gas. The stroke is simply the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting . In most types, the linear movement of the piston is converted to a rotating movement via a connecting rod and

1845-407: The sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine. This seal is usually provided by one or more piston rings . These are rings made of a hard metal, and are sprung into a circular groove in the piston head. The rings fit closely in the groove and press lightly against the cylinder wall to form

Fokker F27 Friendship - Misplaced Pages Continue

1890-538: The successful Douglas DC-3 airliner dominated commuter aviation. Over 10,000 DC-3s had been manufactured during wartime, which led to the type being highly available and thus encouraging its adoption by hundreds of operators across the world. By the early 1950s, various aircraft manufacturers had begun considering the post-war requirements of the civil aviation market and several commenced work upon projects aiming to produce designs for new aircraft which would be viewed as best meeting these requirements; Dutch firm Fokker

1935-504: The type were slow, which led to Fokker seeking financial support from banks and from the Dutch government in order to maintain production of the airliner while more customers were sought. In 1960, demand for the F27 increased rapidly as multiple airlines placed sizable orders for the type. This is in part due to the spreading reputation of the type, having been found by operators that, in comparison to its piston-engine wartime counterparts like

1980-425: Was cabin pressurisation . Innovative manufacturing techniques were also employed in the aircraft's construction. On 24 November 1955, the F27 made its maiden flight ; on 19 November 1958, the type was introduced to revenue service. Shortly after its introduction, the F27 was recognised as being a commercial success. Under a licensing arrangement reached between Fokker and the U.S. aircraft manufacturer Fairchild ,

2025-416: Was amongst the companies pursuing development of such an aircraft. By 1951, figures within Fokker were urging that design work be undertaken on a prospective 32-seat airliner intended as a direct replacement for the popular DC-3. Fokker sought the opinions of existing DC-3 operators on what performance increases and refinements they would expect of a new model of commuter aircraft. On the basis of this feedback,

#483516