Text 2. The four-engine plane

 

Sikorsky had built the first four-engine plane, the Bolsche of 1913. As long as a single aircraft engine could not generate much more than 1, 000 horsepower, multiple engines became the only way to gain the total amount of power necessary to lift the large loads of fuel needed for long journeys. When Pan American sought to open a service from Alameda (Oakland), Calif., to Manila and China, it faced a 2, 400-mile maximum stage between the San Francisco Bay area and Honolulu. Only a four-engine plane could lift enough fuel to make such a “jump.” A further constraint entered the planning: such large planes and the fuel load they would carry could not lift off the ground on the landing strips then available. Only landing on the surface of sheltered waters would provide the thousands of feet required. The Germans in attempting to establish a transatlantic airmail route experimented with artificially calmed stretches of ocean, but the operation was far too risky ever to be used in passenger service. Only through the use of insular stepping-stones properly spaced, such as the Americans controlled west of Honolulu, could an ocean crossing be obtained. In 1932 Pan American signed a contract with Sikorsky to build a four-engine flying boat capable of carrying mail and passengers across the Pacific and a second contract that same year for an even larger flying boat, weighing 26 tons, to be built by Glenn Martin. On Nov. 22, 1935, the first airmail flight left Alameda for Manila using the Martin M-130 (the China Clipper), with a wingspan of 130 feet (equal to the Boeing 727 of a generation later). Passengers were added to the service in 1936, when the first long transoceanic flight began.

The success of these huge flying boats greatly whetted the appetite of American airline operators because it demonstrated the advantages that might be hoped for from four-engine planes, particularly in raising the ceiling on normal commercial flight so that airlines might “fly above the weather.” To do so, it was necessary to artificially pressurize plane cabins above 6, 000 to 8, 000 feet. Half the weight of the atmosphere is normally found below 18, 000 feet, and most of the turbulence is located there. Early experimental flights had shown that as an aircraft rises in the atmosphere it tends to encounter less stormy conditions; most of the “weather” is found below 4, 000 feet. If planes could operate at such higher altitudes, flights would be more comfortable and there would be less resistance to forward movement, allowing the same input of power to move the plane at a greater speed. The first hurdle came in securing an airtight cabin, but success in this operation had to be accompanied by better engines, as was done in the Boeing Stratoliner introduced in 1940. Capable of flying at 14, 000 feet and at a speed of 200 mile/h, the Stratoliner had just begun service when war in Europe broke out; development of this pioneering four-engine plane was taken over by the government for the duration of the war. It was the only commercial aircraft to be able to fly directly from Newfoundland to Northern Ireland during World War II. With its powerful supercharged engines the Stratoliner could navigate not only above weather but over rather than around mountains. Thus routes could be chosen because they formed parts of great circles on the Earth's surface and were thereby the shortest possible distances between two points.

A second four-engine plane was designed just before World War II when the general configuration of the DC-3 was transformed into a four-engine size. Unlike the Stratoliner, this was not a pressurized plane, so it represented the last phase of one line of advance more than the beginning of a postwar design. The enlarged DC-4 was flown throughout the war, becoming the main transatlantic aircraft, in the form of the United States Army's C-54 troop transport.

 

Essential vocabulary:

1. constraint - ограничение
2. strip - полоса
3. surface - поверхность
4. sheltered – скрытый, укрытый
5. to provide – снабжать, обеспечивать
6. to require - требовать
7. available - доступный
8. to attempt - пытаться
9. to establish - устанавливать
10. artificial - искусственный
11. calm – спокойный, тихий
12. stretch - протяженность
13. insular - островной
14. stepping-stone – камень, положенный для перехода через речку
15. airmail - авиапочта
16. wingspan – размах крыльев
17. whet – точить (зд. разжигать, усиливать)
18. ceiling - потолок
19. to encounter – сталкиваться с
20. altitude - высота
21. resistance - сопротивление
22. input - вклад
23. secure – безопасный, защитный
24. hurdle - барьер
25. airtight -герметический
26. to accompany - сопровождать

 

I. Work in pairs. Discuss which sentence in B best continues the sentence in A:

A	B
1. Multiple engines became the only way to gain the total amount of power	a) capable of carrying mail and passengers across the Pacific.
2. Only landing on the surface of sheltered waters	b) and there would be less resistance to forward movement, allowing the same input of power to move the plane at a greater speed.
3. In 1932 Pan American signed a contract with Sikorsky to build a four-engine flying boat	c) plane cabins above 6, 000 to 8, 000 feet.
4. A second four-engine plane was designed just before World War II	d) necessary to lift the large loads of fuel needed for long journeys.
5. If planes could operate at higher altitudes, flights would be more comfortable	e) would provide the thousands of feet required.
6. It was necessary to artificially pressurize	f) when the general configuration of the DC-3 was transformed into a four-engine size.

 

 

II. Look at the groups of words below. Which word is the odd one?

1. a) engine b) power c) fuel d) load
2. a) plane b) altitude c) aircraft d) flying boat
3. a) to land b) to lift off c) to fly d) to function
4. a) cosmonaut b) pilot c) operator d) passenger
5. a) cabin b) wingspan c) distance d) fuselage
6. a) navigation b) controlling c) operation d) duration
7. a) altitude b) distance c) plane d) velocity

 

III. Complete the sentences:

1. When Pan American sought to open a service from Alameda to Manila and China, it faced a 2, 400-mile … … between the San Francisco Bay area and Honolulu.
2. The Germans in attempting to establish a transatlantic … … experimented with artificially calmed stretches of ocean, but the operation was too risky to be used in passenger service.
3. Passengers were added to the service in 1936, when the first long … … began.
4. Half the weight of the atmosphere is normally found …18, 000 feet, and most of the … is located there.
5. … was the only commercial aircraft to be able to fly directly from Newfoundland to Northern Ireland during … ….
6. The enlarged … was flown throughout the war, becoming the main transatlantic ….

 

IV. Answer the following questions:

1. Who built the first four-engine plane? What was it?
2. How could the ocean crossing be obtained?
3. What and why did whet the appetite of American airline operators?
4. What was the first hurdle in the constructing of the passenger plane?
5. When was Stratoliner first introduced? What an aircraft was it?
6. What was the second four-engine plane? Was it differ from Stratoliner?

 

 

Text 3. AIRCRAFT

During those years which have passed since the first aeroplane was built, aviation has enjoyed phenomenal progress. At present aviation influences many aspects of social life.

In the dynamic world of today, aviation provides a rapid transportation link between different population centres. In many places the aeroplane is the only known vehicle for the large-scale movement of passengers and freight over large distances. The airplane has made it possible to patrol the forests, to fight their fires, to assess their timber resources and to plan their harvesting. It has made an enormous contribution to the photographing and mapping of the vast territories, to exploring and prospecting for mineral wealth and to studying and assessing the water resources.

As for the helicopter, besides its use for passenger transportation, this type of aircraft has proved its value in special applications where vertical take off-landing are required. Helicopters are widely used in search and rescue operations in emergency situations or when some accident occurs.

The main components of airplanes are as follows:

1. The fuselage is the main body of the airplane and contains the pilot's compartment (cockpit) and passenger and baggage compartments. The cockpit contains the flight controls and instruments.

2. The wings are the main lifting surfaces which support the aircraft in flight. Aircraft may be divided into monoplanes and biplanes.

3. The tail unit or empennage consists of a vertical stabilizer and rudder and the horizontal stabilizer and elevators to provide the necessary stability in flight.

4. The three basic flight control surfaces are the ailerons, the elevators and the rudder.

5. The power plant is the heart of the airplane. There are many types of engines: turboprop, turbojet, turbofan, rocket engines, etc.

6. The landing gear or undercarriage is used during manoeuvering of the aircraft on the ground while taxying, taking off and landing. In flight the retractable landing gear is retracted into the wing or the fuselage structure.

AIRCRAFT INSTRUMENTS

Aircraft instruments are basically devices for obtaining information about the aircraft and its environment and for presenting that information to the pilot. Their purpose is to detect, measure, record, process and analise the variables encountered in flying an aircraft. They are mainly electrical, electronic or gyroscopic. Modern aircraft have a computer on board. They are concerned with the behavior of the engines, the speed, height and attitude of the aircraft and its whereabouts. Instruments concerned with the whereabouts of an aircraft are navigation instruments.

An aircraft usually takes the name of the designer or manufacturer. Here are some of the Russian designers: Tupolev, Ilyushin, Antonov, Yakovlev. Manufacturer's names are represented by Boeing, Douglas, Lockheed and others. The name of the designer or manufacturer is followed by a type code, known in some airlines as a class. For example: Ilyushin-96 (designer's name and type code), Boeing-747 (manufacturer's name and type code).

Exercises

 

I. Ответьте на вопросы:

1. What does aviation provide?
2. Where are helicopters used?
3. What types of aircraft do you know?
4. Name the main parts of the aircraft.
5. What does the fuselage contain?
6. What for are the wings required?
7. What are the components of the wing?
8. What does the tail unit provide?
9. What is the power plant?
10. What types of engines do you know?
11. When are the landing gears used?
12. What is the purpose of aircraft instruments?
13. What Russian and foreign designers do you know?
14. What name does the aircraft take?

 

II. Переведите слова, обращая внимание на словообразующие элементы:

transport – transportation

move – movement – movable

possible – possibility – impossible

apply - application

power – powerful

retract – retraction – retractable - unretractable

require – requirement

provide – provision

measure – measurement

contribute – contribution

 

III. Найдите в тексте эквивалент следующим словосочетаниям:

 

населенный центр, минеральные и водные ресурсы, применение авиации, перевозка пассажиров, пассажирское и грузовое отделения, приборы самолета, навигационные приборы, рули управления самолетом, пилотская кабина, конструкция фюзеляжа, аварийная ситуация, поисково-спасательные операции.

 

IV. Переведите на английский язык:

1. Огромный прогресс сделан в авиации за последнее десятилетие.
2. Авиация применяется во многих аспектах общественной жизни.
3. Авиация обеспечивает быструю перевозку пассажиров и груза из одной точки в другую.
4. В некоторых местах авиация является единственным средством перевозки.
5. Вертолет удобное средство передвижения благодаря вертикальному взлету и посадки.
6. Фюзеляж является основной частью самолета.
7. Несущими поверхностями самолета являются крылья.
8. Крылья и хвостовое оперение состоят из подвижных частей, таких как руль высоты, руль поворота, руль направления, стабилизатор, элерон.
9. Шасси используются при рулении на земле и убираются в крыло после взлета.
10. В кабине пилота много приборов, показывающих скорость и высоту полета, работу двигателя и другую информацию.
11. Современные самолеты имеют на борту компьютер.

 

Text 4. Helicopter (I)

Helicopter is an aircraft with one or more power-driven horizontal propellers or rotors that enable it to take off and land vertically, to move in any direction, or to remain stationary in the air. Other vertical-flight craft include autogiros, convertiplanes, and V/STOL aircraft of a number of configurations.

The idea of taking off vertically, making the transition to horizontal flight to the destination, and landing vertically has been for centuries the dream of inventors. It is the most logical form of flight, dispensing as it does with large landing fields located far from city centres and the inevitable intervening modes of travel—automobile, subway, bus—that flight in conventional aircraft usually requires. But vertical flight is also the most demanding challenge in flying, requiring more sophistication in structure, power, and control than conventional fixed-wing aircraft. These difficulties, solved over time by determined engineers and inventors, made the progress of vertical flight seem slow compared to that of conventional flight, for the first useful helicopters did not appear until the early 1940s.

 

Helicopters (Principles of flight and operation)

Unlike fixed-wing aircraft, the helicopter's main airfoil is the rotating blade assembly (rotor) mounted atop its fuselage on a hinged shaft (mast) connected with the vehicle's engine and flight controls. In comparison to airplanes, the tail of a helicopter is somewhat elongated and the rudder smaller; the tail is fitted with a small antitorque rotor (tail rotor). The landing gear sometimes consists of a pair of skids rather than wheel assemblies.

The fact that the helicopter obtains its lifting power by means of a rotating airfoil (the rotor) greatly complicates the factors affecting its flight, for not only does the rotor turn but it also moves up and down in a flapping motion and is affected by the horizontal or vertical movement of the helicopter itself. Unlike the usual aircraft airfoils, helicopter rotor airfoils are usually symmetrical. The chord line of a rotor, like the chord line of a wing, is an imaginary line drawn from the leading edge to the trailing edge of the airfoil.

The relative wind is the direction of the wind in relation to the airfoil. In an airplane, the flight path of the wing is fixed in relation to its forward flight; in a helicopter, the flight path of the rotor advances forward (to the helicopter's nose) and then rearward (to the helicopter's tail) in the process of its circular movement. Relative wind is always considered to be in parallel and opposite direction to the flight path. In considering helicopter flight, the relative wind can be affected by the rotation of the blades, the horizontal movement of the helicopter, the flapping of the rotor blades, and wind speed and direction. In flight, the relative wind is a combination of the rotation of the rotor blade and the movement of the helicopter.

Like a propeller, the rotor has a pitch angle, which is the angle between the horizontal plane of rotation of the rotor disc and the chord line of the airfoil. The pilot uses the collective and cyclic pitch control to vary this pitch angle. In a fixed-wing aircraft, the angle of attack (the angle of the wing in relation to the relative wind) is important in determining lift. The same is true in a helicopter, where the angle of attack is the angle at which the relative wind meets the chord line of the rotor blade.

Angle of attack and pitch angle are two distinct conditions. Varying the pitch angle of a rotor blade changes its angle of attack and hence its lift. A higher pitch angle (up to the point of stall) will increase lift; a lower pitch angle will decrease it. Individual blades of a rotor have their pitch angles adjusted individually.

Rotor speed also controls lift—the higher the revolutions per minute (rpm), the higher the lift. However, the pilot will generally attempt to maintain a constant rotor rpm and will change the lift force by varying the angle of attack.

As with fixed-wing aircraft, air density (the result of air temperature, humidity, and pressure) affects helicopter performance. The higher the density, the more lift will be generated; the lower the density, the less lift will be generated. Just as in fixed-wing aircraft, a change in lift also results in a change in drag. When lift is increased by enlarging the angle of pitch and thus the angle of attack, drag will increase and slow down the rotor rpm. Additional power will then be required to sustain a desired rpm. Thus, while a helicopter is affected like a conventional aircraft by the forces of lift, thrust, weight, and drag, its mode of flight induces additional effects.

 

Essential vocabulary:

1. to take off - взлетать
2. stationary - неподвижный
3. autogiro - автожир
4. transition - переход
5. destination – место назначения
6. to dispense - распределять
7. inevitable - неизбежный
8. intervening modes – появляющиеся способы, методы
9. to require - требовать
10. sophistication - сложность
11. to determine – определять, устанавливать
12. airfoil – аэродинамический профиль
13. blade - лопасть
14. to mount – прикреплять, устанавливать
15. mast - мачта
16. to advance - продвигаться
17. chord line – прямая линия
18. trailing edge – ребро, край
19. to affect - влиять
20. to flap – развеваться, махать
21. pitch - шаг
22. angle - угол
23. humidity - влажность
24. performance – летные данные
25. to sustain – поддерживать, выдерживать, нести
26. thrust – тяга, толчок
27. drag - торможение
28. to induce - порождать
29. to generate - производить

 

Text 5. Helicopter (II)

 

In a helicopter, the total lift and thrust forces generated by the rotor are exerted perpendicular to its plane of rotation. When a helicopter hovers in a windless condition, the plane of rotation of the rotor is parallel to the ground, and the sum of the weight and drag forces are exactly balanced by the sum of the thrust and lift forces. In vertical flight, the components of weight and drag are combined in a single vector that is directed straight down; the components of lift and thrust are combined in a single vector that is directed straight up. To achieve forward flight in a helicopter, the plane of rotation of the rotor is tipped forward. (It should be understood that the helicopter's rotor mast does not tip but rather the individual rotor blades within the plane of rotation have their pitch angle varied.) For sideward flight, the plane of the rotation of the rotor is tilted in the direction desired. For rearward flight, the plane of the rotation of the rotor is tilted rearward.

Because the rotor is powered, there is an equal and opposite torque reaction, which tends to rotate the fuselage in a direction opposite to the rotor. This torque is offset by the tail rotor located at the end of the fuselage. The pilot controls the thrust of the tail rotor by means of foot pedals, neutralizing torque as required.

There are other forces acting upon a helicopter not found in a conventional aircraft. These include the gyroscopic precession effect of the rotor—that is, the dissymmetry of lift created by the forward movement of the helicopter, resulting in the advancing blade having more lift and the retreating blade less. This occurs because the advancing blade has a combined speed of the blade velocity and the speed of the helicopter in forward flight, while the retreating blade has the difference between the blade velocity and the speed of the helicopter. This difference in speed causes a difference in lift—the advancing blade is moving faster and hence is generating more lift. If uncontrolled, this would result in the helicopter rolling. However, the difference in lift is compensated for by the blade flapping and by cyclic feathering (changing the angle of pitch). Because the blades are attached to a rotor hub by horizontal flapping hinges, which permit their movement in a vertical plane, the advancing blade flaps up, decreasing its angle of attack, while the retreating blade flaps down, increasing its angle of attack. This combination of effects equalizes the lift. (Blades also are attached to the hub by a vertical hinge, which permits each blade to move back and forth in the plane of rotation. The vertical hinge dampens out vibration and absorbs the effect of acceleration or deceleration.) In addition, in forward flight, the position of the cyclic pitch control causes a similar effect, contributing to the equalization of lift.

Other forces acting upon helicopters include coning, the upward bending effect on blades caused by centrifugal force; Coriolis effect, the acceleration or deceleration of the blades caused by the flapping movement bringing them closer to (acceleration) or farther away from (deceleration) the axis of rotation; and drift, the tendency of the tail rotor thrust to move the helicopter in hover.

 

Essential vocabulary:

1. thrust force – сила тяги
2. to exert – оказывать, действовать
3. plane of rotation – плоскость вращения
4. to hover - реять
5. drag force – тормозная сила
6. to tip - наклоняться
7. mast - мачта
8. to tilt – наклонять
9. pitch angle – угол наклона
10. torque – вращающий момент
11. offset – офсет, смещение, сдвиг
12. gyroscopic precession effect – эффект гироскопической прецессии
13. retreat - отступление
14. rolling – прокрутка, прокатывание
15. flapping hinge – маховик (шарнир), закрылок
16. hub – узел, втулка
17. feathering – вращение (по принципу пера), резать крылом воздух
18. to permit – позволять, разрешать
19. to attach – прикреплять
20. to increase – увеличивать, повышать
21. to decrease – снижать, уменьшать
22. to equalize - выравнивать
23. to dampen out – демпфировать, тормозить
24. to absorb – поглощать, впитывать
25. to contribute – содействовать
26. coning – конус
27. bending – изгиб
28. centrifugal force – центробежная сила
29. acceleration – ускорение
30. drift – парение, дрейф

 

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