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Parachute

Parachute

 

IN 9TH century Islamic Spain, Abbas Ibn Firnas (Armen Firnas) invented a primitive version of the parachute. John H. Lienhard described it in The Engines of Our Ingenuity as follows:

Abbas Ibn Firnas, also known as Abbas Qasim Ibn Firnas was a Muslim Andalusian polymath an inventor, engineer, aviator, physician, Arabic poet, and Andalusian musician. He is known for an early attempt at aviation.

“In 852, a new Caliph and a bizarre experiment: A daredevil named Armen Firman (Armen Firman may be the Latinized name of Abbas Ibn Firnas, or, alternatively, he may have been the man who inspired Ibn Firnas) decided to fly off a tower in Cordova. He glided back to earth, using a huge winglike cloak to break his fall. He survived with minor injuries, and the young Ibn Firnas was there to see it.”

Ibn Firnas is also said to have made an attempt at flight using a set of wings. The only evidence for this is an account by the Moroccan historian Ahmed Mohammed al-Maqqari, composed seven centuries later.

Among other very curious experiments which he made, one is his trying to fly. He covered himself with feathers for the purpose, attached a couple of wings to his body, and, getting on an eminence, flung himself down into the air, when according to the testimony of several trustworthy writers who witnessed the performance, he flew a considerable distance, as if he had been a bird, but, in alighting again on the place whence he had started, his back was very much hurt, for not knowing that birds when they alight come down upon their tails, he forgot to provide himself with one.

Today parachute is a device used to slow the motion of an object through an atmosphere by creating drag, or in the case of ram-air parachutes, aerodynamic lift. Parachutes are usually made out of light, strong cloth, originally silk, now most commonly nylon. Parachutes must slow an object’s terminal vertical speed by a minimum 75% in order to be classified as such. Depending on the situation, parachutes are used with a variety of loads, including people, food, equipment, space capsules, and bombs.

A hand-deployed pilot chute, once thrown into the air stream, pulls a closing pin on the pilot chute bridle to open the container, then the same force extracts the deployment bag. There are variations on hand-deployed pilot chutes, but the system described is the more common throw-out system.

Only the hand-deployed pilot chute may be collapsed automatically after deployment—by a kill line reducing the in-flight drag of the pilot chute on the main canopy. Reserves, on the other hand, do not retain their pilot chutes after deployment. The reserve deployment bag and pilot chute are not connected to the canopy in a reserve system. This is known as a free-bag configuration, and the components are often lost during a reserve deployment.

Paratroopers’ main parachutes are usually deployed by static lines that release the parachute, yet retain the deployment bag that contains the parachute—without relying on a pilot chute for deployment. In this configuration the deployment bag is known as a direct-bag system, in which the deployment is rapid, consistent, and reliable. This kind of deployment is also used by student skydivers going through a static line progression, a kind of student program.