Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Тексты.doc
Скачиваний:
7
Добавлен:
12.04.2015
Размер:
470.53 Кб
Скачать

Essential vocabulary:

  1. to consider – рассматривать, считать, решать

  2. topassover– пропускать, переходить, обновить

  3. to seek- искать

  4. site- место

  5. persistent– устойчивый (постоянный)

  6. hill- холм

  7. to glide– скользить, планировать

  8. to secure– закреплять (обозначать)

  9. frame- рамка

  10. biplane- биплан

  11. wingspan– размах крыльев

  12. to equip– оборудовать, оснащать

  13. engine- двигатель

  14. to aid- помогать

  15. accomplishment– выполнение, осуществление

  16. essential– главный, основной

  17. harness– упряжь (зд. обуздать, поймать)

  18. to supply– поставлять, обеспечивать

  19. steer- управление

  20. subsequently- впоследствии

  21. significant invention– важное открытие

  22. to convince- убеждать

  23. to warp- поворачивать

  24. to distort- искажать

  25. fashion- способ

  26. ridged- гребенчатый

  27. wire– шнур, провод

  28. edge– край, ребро

  29. sustained– поддерживать, выдерживать

  30. proprietary– личный, патентованный

  31. contribution- вклад

I. Answer the following questions:

  1. Why did the Wright brothers seek a site with a strong and persistent wind?

  2. Who was the first man to fly in an aeroplane?

  3. Why did neither balloons and dirigibles nor ornithopter experiments produce flight?

  4. What was the most significant invention of the Wright brothers?

  5. How many flights did the Wrights make during the 1904?

  6. When did the Wrights stop experiments and break their cecrecy?

II. Find the English equivalents of the following phrases in the text:

  • сильный постоянный ветер

  • вскоре продемонстрировали

  • абсолютно не важен (нужен)

  • зафиксированный на краю крыла

  • изогнутое крыло

  • подняться с земли (взлететь)

  • движение (динамика) атмосферы

  • один способ или другой

  • расстояние в 120 футов

  • изменяющиеся направления

  • произвести полет (полететь)

  • получить патент на изобретение

III. Make up your own sentences with the phrases and words listed above.

IV. Make up a dialogue. Your partner is one of the Wright brothers (Wilbur or Orville) who is telling about their invention and you are a French journalist who is interviewing him.

Differences in helicopter and airplane design and construction

The most obvious difference in the construction of a fixed-wing aircraft and a helicopter is of course the latter's use of a rotor instead of a wing. There are many other additions, however, including the use of a tail rotor to offset torque. (Some helicopters use a “no tail rotor” system, in which low-pressure air is circulated through a tail boom to control the torque of the spinning main rotor.) Less obvious are such additions as the transmission system, which is used to transfer power from the engine to the rotor, tail rotor, and other accessories; the clutch, used to engage the engine and transmission with the rotor; and the mechanics of the rotor system itself.

The first helicopters were quite primitive, with skids instead of wheeled landing gear, open cockpits, and unaired fuselage sections. Helicopters are now as fully equipped as airplanes, with retractable landing gear and full instrumentation and navigation equipment, and are provided with accoutrements may be necessary to accomplish the specific task at hand. For example, some helicopters are flying ambulances, especially equipped with a complete set of intensive-care accessories. Others function as electronic news gatherers, with appropriate sensors and telecommunications equipment.

The design and operation of helicopters have derived the same advances from computers and composites as have other aircraft, especially in the design and construction of the rotor blades. One of the more important improvements is in the simplification of flight-control systems, where a simple side stick controller, with the assistance of computers, performs the functions of the collective, cyclic, and throttle controls.

Helicopter designs have included a number of optional rotor configurations, such as rotors that stop to serve as a fixed wing for forward flight; rotors that fold and can be stowed within the fuselage contours, lift being provided by a stub wing; and X-shaped rotors that rotate for takeoff and landing but are fixed for lift in flight.

In sum, the additional forces imposed upon a helicopter by its very concept delayed its development, made it relatively more difficult to control than fixed-wing aircraft, and, in general, impeded its use. While generally considered more expensive to operate than conventional fixed-wing aircraft, a true comparison of costs cannot be made without assessing the additional advantages conferred by the vertical flight capability. The popularity of the helicopter indicates that users pay any additional costs to obtain that capability. In some applications—medical evacuation, supplying of oil drilling rigs, spreading of certain agricultural agents, to name but a few—it is irreplaceable.

Walter James Boyne

Тут вы можете оставить комментарий к выбранному абзацу или сообщить об ошибке.

Оставленные комментарии видны всем.