catapult
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catapult
Catapult
(1) In military terminology a throwing machine activated by the elastic force of twisted cords made from sinews, hair, and so forth. Catapults were used in ancient Greece and Rome up to the end of the fifth century mainly for besieging fortresses; lightweight versions (from the fourth century B.C.) were also used in field combat. Catapults hurled stones, logs, barrels with burning tar, and other objects over distances of a few hundred meters and lances up to 185 cm long and weighing up to 1.5 kg over distances up to 150 m.
(2) A device for imparting initial (launch) velocity to airplanes, gliders, and so forth on a short runway. A catapult consists of a driving apparatus (trolley, “shuttle”, hook, etc.), a guiding device (usually rails), and a launching mechanism. The driving apparatus with the aircraft attached to it is accelerated either by a jet engine or by employing the energy of steam, gunpowder, compressed air, springs, or rubber bands. Toward the end of the takeoff run, the driving mechanism is abruptly halted, and the aircraft separates from the driving apparatus with the necessary velocity for independent flight.
Catapults with horizontal guiding devices are employed mainly on aircraft carriers, where steam catapults are usually employed that provide an airplane acceleration on a runway of 60–80 m up to a velocity of 200–300 km/hr. Catapults with vertical guiding devices are used for practicing ejection from airplanes on the ground, training flight crews, and studying the effects of great strains on man over short time periods.
REFERENCE
Korotkin, I. M., Z. F. Slepenkov, and B. A. Kolyzaev. Avianostsy. Moscow. 1964.G. M. BADAEV and E. P. GOLUBKOV
catapult
[′kad·ə‚pəlt]catapult
ii. To eject a person from an airplane by means of a catapult.