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    Build Your Own Parachute
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    Parachute and Parachuting Experiments

    Parachute Background Information

    Definitions

    A parachute is usually an umbrella shaped device on which people or things can float slowly and safely down to the ground from a great height, such as an aircraft.

    Parachuting, also known as skydiving, is the activity of jumping from enough height to deploy a fabric parachute and land.

    Basics

    The word parachute comes from the French words parer meaning to protect and chute meaning fall carefully down making sure you are safe.Drogue parachutes are used to aid horizontal deceleration of a vehicle (a fixed-wing aircraft, or a drag racer), or to provide stability (tandem free-fall, or space shuttle after touchdown).

    Parachutes have got a lot of air resistance which means what ever is inside is safe and secure. If there was no air restance in parachutes people would injur themseves but they have got air restistance so people are safer.

    Parachute's are used in a sport called parchuting.

    The great inventor Leonardo Da Vinci believed that one day humans would fly . Most of his inventions were never made. However, we found notebooks containing drawings of parachutes and decided to build it

    The word "parachute" comes from "para", meaning "against" or "counter" in Ancient Greek, and "chute", the French word for "fall". Some modern parachutes are classified as semi-rigid wings, which are maneuverable and can make a controlled descent to break on impact with the ground. Only slightly later, a more sophisticated parachute was sketched by the polymath Leonardo da Vinci in his Codex Atlanticus (fol. 381v) dated to ca. 1485. Here, the scale of the parachute is in a more favorable proportion to the weight of the jumper. Leonardo's canopy was held open by a square wooden frame, which alters the shape of the parachute from conical to pyramidal. It is not known whether the Italian inventor was influenced by the earlier design, but he may have learnt about the idea through the intensive oral communication among artist-engineers of the time. The feasibility of Leonardo's pyramidal design was successfully tested in 2000 by the British Adrian Nicholas and again in 2008 by another skydiver. According to the historian of technology Lynn White, these conical and pyramidal designs, much more elaborate than early artistic jumps with rigid parasols in Asia, mark the origin of "the parachute as we know it".

    The oldest known depiction of a parachute, by an anonymous author (Italy, 1470s).

    An American paratrooper using an MC1-1C series 'round' parachute. A parachute is carefully folded, or "packed" to ensure that it will open reliably. If a parachute is not packed properly it can result in death because the main parachute might fail to deploy correctly or fully. In the U.S. and many developed countries, emergency and reserve parachutes are packed by "riggers" who must be trained and certified according to legal standards. Sport skydivers are always trained to pack their own primary "main" parachutes.

    Parachutes can malfunction in several ways. Malfunctions can range from minor problems that can be corrected in-flight and still be landed, to catastrophic malfunctions that require the main parachute to be cut away using a modern 3-ring release system, and the reserve be deployed. Most skydivers also equip themselves with small barometric computers (known as an AAD or automatic activation device like Cypres, FXC or Vigil) that will automatically activate the reserve parachute if the skydiver himself has not deployed a parachute to reduce his rate of descent by a preset altitude.

    Exact numbers are difficult to estimate, but approximately one in a thousand sports main parachute openings malfunction, and must be cut away, although some skydivers have many hundreds of jumps and never cut away. Reserve parachutes are packed and deployed differently. They are also designed more conservatively, and are built and tested to more exacting standards, making them more reliable than main parachutes. However, the primary safety advantage of a reserve chute comes from the probability of an unlikely main malfunction being multiplied by the even less likely probability of a reserve malfunction. This yields an even smaller probability of a double malfunction, although the possibility of a main malfunction that cannot be cut away causing a reserve malfunction is a very real risk. In the U.S., the average fatality rate is considered to be about 1 in 80,000 jumps. Most injuries and fatalities in sport skydiving occur under a fully functional main parachute because the skydiver made an error in judgment while flying the canopy—resulting in high-speed impact with the ground, impact with a hazard on the ground that might otherwise have been avoided, or collision with another skydiver under canopy.

    Topics of Interest

    The earliest evidence for the parachute dates back to the Renaissance period. The oldest parachute design appears in an anonymous manuscript from 1470s Renaissance Italy (British Museum Add. MSS 34,113, fol. 200v), showing a free-hanging man clutching a cross bar frame attached to a conical canopy. As a safety measure, four straps run from the ends of the rods to a waist belt. The design is a marked improvement over another folio (189v) which depicts a man trying to break the force of his fall by the means of two long cloth streamers fastened to two bars which he grips with his hands. Although the surface area of the parachute design appears to be too small to offer effective resistance to the friction of the air and the wooden base-frame is superfluous and potentially harming, the revolutionary character of the new concept is obvious.

    The modern parachute was invented in the late 18th century by Louis-Sébastien Lenormand in France, who made the first recorded public jump in 1783. Lenormand also sketched it beforehand. Two years later, Jean-Pierre Blanchard demonstrated it as a means of safely disembarking from a hot air balloon. While Blanchard's first parachute demonstrations were conducted with a dog as the passenger, he later had the opportunity to try it himself in 1793 when his hot air balloon ruptured and he used a parachute to escape.

    Round parachutes are purely drag devices (that is, unlike the ram-air types, they provide no lift) and are used in military, emergency and cargo applications. These have large dome-shaped canopies made from a single layer of triangular cloth gores. Some skydivers call them "jellyfish 'chutes" because of the resemblance. Modern sports parachutists rarely use this type.

    The unique design characteristics of cruciform (square) parachutes reduces oscillations (its user swinging back and forth) and violent turns during descent. This technology will be used by the US Army as it replaces its current T-10 parachutes under a program called ATPS (Advanced Tactical Parachute System). The ATPS canopy is a highly modified version of a cross/ cruciform platform and is square in appearance. The ATPS (T-11) system will reduce the rate of descent by 30 percent from 21 feet per second (6.4 m/s) to 15.75 feet per second (4.80 m/s). The T-11 is designed to have an average rate of descent 14% slower than the T-10D thus resulting in lower landing injury rates for jumpers. The decline in rate of descent will reduce the impact energy by almost 25% to lessen the potential for injury.

    Ribbon and ring parachutes have similarities to annular designs. They are frequently designed to deploy at supersonic speeds. A conventional parachute would instantly burst upon opening at such speeds. Ribbon parachutes have a ring-shaped canopy, often with a large hole in the center to release the pressure. Sometimes the ring is broken into ribbons connected by ropes to leak air even more. These large leaks lower the stress on the parachute so it does not burst or shred when it opens. Ribbon parachutes made of kevlar are used on nuclear bombs such as the B61 and B83.

    Most modern parachutes are self-inflating "ram-air" airfoils known as a parafoil that provide control of speed and direction similar to paragliders. Paragliders have much greater lift and range, but parachutes are designed to handle, spread and mitigate the stresses of deployment at terminal velocity. All ram-air parafoils have two layers of fabric; top and bottom, connected by airfoil-shaped fabric ribs to form "cells." The cells fill with high pressure air from vents that face forward on the leading edge of the airfoil. The fabric is shaped and the parachute lines trimmed under load such that the ballooning fabric inflates into an airfoil shape. This airfoil is sometimes maintained by use of fabric one-way valves called Airlocks.

    A parachute is carefully folded, or "packed" to ensure that it will open reliably. If a parachute is not packed properly it can result in death because the main parachute might fail to deploy correctly or fully. In the U.S. and many developed countries, emergency and reserve parachutes are packed by "riggers" who must be trained and certified according to legal standards. Sport skydivers are always trained to pack their own primary "main" parachutes.

    Parachutes can malfunction in several ways. Malfunctions can range from minor problems that can be corrected in-flight and still be landed, to catastrophic malfunctions that require the main parachute to be cut away using a modern 3-ring release system, and the reserve be deployed. Most skydivers also equip themselves with small barometric computers (known as an AAD or automatic activation device like Cypres, FXC or Vigil) that will automatically activate the reserve parachute if the skydiver himself has not deployed a parachute to reduce his rate of descent by a preset altitude.

    Exact numbers are difficult to estimate, but approximately one in a thousand sports main parachute openings malfunction, and must be cut away, although some skydivers have many hundreds of jumps and never cut away. Reserve parachutes are packed and deployed differently. They are also designed more conservatively, and are built and tested to more exacting standards, making them more reliable than main parachutes. However, the primary safety advantage of a reserve chute comes from the probability of an unlikely main malfunction being multiplied by the even less likely probability of a reserve malfunction. This yields an even smaller probability of a double malfunction, although the possibility of a main malfunction that cannot be cut away causing a reserve malfunction is a very real risk. In the U.S., the average fatality rate is considered to be about 1 in 80,000 jumps. Most injuries and fatalities in sport skydiving occur under a fully functional main parachute because the skydiver made an error in judgment while flying the canopy—resulting in high-speed impact with the ground, impact with a hazard on the ground that might otherwise have been avoided, or collision with another skydiver under canopy.

    Free fall describes any motion initiated solely by the force of gravity. Since this definition does not specify velocity, it also applies to objects initially moving upward. Although strictly the definition excludes motion of an object subjected to aerodynamic drag, in nontechnical usage falling through an atmosphere without a deployed parachute or lifting device is also referred to as free fall.

    Paratroopers are soldiers trained in parachuting and generally operate as part of an airborne force.

    A powered parachute (motorized parachute, PPC, paraplane) is a parachute with motor and wheels.

    Parachute cord (also paracord or 550 cord) is a lightweight nylon kernmantle rope originally used in the suspension lines of US parachutes during World War II. Once in the field, paratroopers found this cord useful for many other tasks. It is now used as a general purpose utility cord by both military personnel and civilians. This versatile cord was even used by astronauts during STS-82, the second Space Shuttle mission to repair the Hubble Space Telescope.

    A parachute rigger is a person who is trained or licenced to pack, maintain or repair parachutes. A rigger is required to understand fabrics, hardware, webbing, regulations, sewing, packing, and other aspects related to the building, packing, repair, and maintenance of parachutes.

    A drogue parachute is a parachute designed to be deployed from a rapidly moving object. It is often used to gain control of very fast descents, including those of spacecraft during atmospheric reentry, or nuclear bombs such as the B61 and B83.

    Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License and Creative Commons Attribution-ShareAlike License.)

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