A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward, and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of vertical takeoff and landing aircraft cannot perform.
Название: Helicopters (20th Century Weapons)
Издательство: Franklin Watts
Автор: Charles Messenger
Год издания: 1985
Формат: PDF
Страниц: 54
Язык: English
Размер: 45 MB
Скачать бесплатно / free download
=============================
=============================
