A parachute is a device used to slow the motion of an object through an atmosphere by creating drag. Paratroopers are Soldiers trained in Parachuting and generally operate as part of an airborne force. In Fluid dynamics, drag (sometimes called fluid resistance) is the force that resists the movement of a Solid object through a Fluid (a

Parachutes are normally used to slow the descent of a person or object to Earth or another celestial body within an atmosphere. s are significant physical entities, associations or structures which current Science has confirmed to exist in Space. An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " Drogue parachutes are also sometimes 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). A drogue parachute is a Parachute designed to be deployed from a rapidly moving object Overview Fixed-wing aircraft range from small training and recreational aircraft to Wide-body aircraft and military cargo aircraft. Drag racing is a competition in which objects compete to be the first to cross a set finish mark usually from a dead stop and in a straight line NASA 's Space Shuttle, officially called the Space Transportation System ( STS) is the Spacecraft currently used by the United States The word "parachute" comes from a French word with a Latin root: "para", meaning "against" or "counter" in Latin, and "chute", the French word for "fall". Therefore "parachute" actually means "against the fall". Many modern parachutes are classified as semi-rigid wings, which are quite maneuverable, and can facilitate a controlled descent similar to that of a glider. Terminology A "glider" is an unpowered Aircraft. The most common types of glider are today used for sporting purposes But older style parachutes were little more than cloth and sticks. The design has changed considerably over the years from roughly cut shapes to aerodynamic ram parachutes. Folding a parachute requires a high degree of skill, and an improperly folded parachute will not deploy, which could end up with deadly results.

Parachutes were once made from silk but now they are almost always constructed from more durable woven nylon fabric, sometimes coated with silicone to improve performance and consistency over time. Eventually parachutes need to be replaced as they deteriorate, as failure to do so could result in loss of life.

When square (also called ram-air) parachutes were introduced, manufacturers switched to low-stretch materials like Dacron or zero-stretch materials like Spectra, Kevlar, Vectran and high-modulus aramids. Uses PET can be semi-rigid to rigid depending on its thickness and is very lightweight Kevlar is the registered Trademark for a light strong para-aramid Synthetic fiber, related to other Aramids such as Nomex and Vectran is a manufactured fibre spun from a Liquid crystal polymer created by Celanese Acetate LLC and now manufactured by Kuraray Co Aramid fibers are a class of heat-resistant and strong Synthetic fibers They are used in aerospace and military applications for ballistic rated body armor

Contents 1 Early forms 2 Modern parachutes 3 Design 3.1 Deployment system 4 Types of parachutes 4.1 Round parachutes 4.2 Cruciform (square) parachutes 4.3 Annular and pull-down apex parachutes 4.4 Ribbon and ring parachutes 4.5 Ram-air parachutes 5 Personnel parachutes 5.1 Deployment 5.2 Varieties of personal ram-airs 5.3 General characteristics of ram-airs 6 Safety 7 Parachute malfunctions 8 References 9 External links

Early forms

The first successful test of a parachute was made in 1603 in Bratislava, Slovakia by Štefan Banič. ARTICLE TEXT BEGINS AFTER THESE COMMENTS - PLEASE READ 1 Please do not edit the lead without reading Slovakia (long form Slovak Republic; Slovak:, long form, is a Landlocked country in Central Europe with a population of over five million Štefan Banič ( 23 November 1870 - 2 January, 1941) is the Inventor of the military Parachute and of the first actually .

In 9th century Al-Andalus, Abbas Ibn Firnas (Armen Firnas) developed a primitive form of parachute. Al-Andalus (الأندلس was the Arabic name given to those parts of the Iberian Peninsula governed by Muslims or Abbas Ibn Firnas (810 &ndash 887 AD) was also known as Abbas Qasim Ibn Firnas and العباس بن فرناس ( Arabic language) ^[1][2][3][4] John H. Lienhard described it in The Engines of Our Ingenuity as "a huge winglike cloak to break his fall" when he "decided to fly off a tower in Cordova". ^[5]

A conical parachute appears for the first time in the 1470s in an Italian manuscript, slightly preceding Leonardo da Vinci's conical parachute designs. Leonardo di ser Piero da Vinci ( April 15 1452 – May 2 1519 was an Italian Polymath, having been a scientist Mathematician, Engineer ^[6] It was intended as an escape device to allow people to jump from burning buildings, but there is no evidence that it was actually ever used. Leonardo da Vinci sketched a parachute while he was living in Milan around 1480-1483: a pyramid-shaped canopy held open by a square wooden frame. Milan (Milano Milan (listen) is one of the largest cities in Italy, located in the plains of Lombardy.

The first parachute was invented in 1595 by the Croatian inventor Faust Vrančić, who named its invention Homo Volans (Flying Man). Croatia (Hrvatska ˈxȓvatska officially the Republic of Croatia ( Republika Hrvatska) is a southern Central European country at the crossroads between Faust Vrančić (1551 Šibenik – January 17 1617) was a Croatian humanist Philosopher, Historian, Diplomat

Twenty years later, he implemented his design and tested the parachute by jumping from a tower in Venice in 1617. Towers are tall human-made Structures that are always taller than they are wide usually by a significant Margin. The event was documented some 30 years after it happened in a book written by John Wilkins, the secretary of the Royal Society in London^[7]. John Wilkins ( January 1, 1614 - November 19, 1672) was an English clergyman and author The Royal Society of London for the Improvement of Natural Knowledge, known simply as The Royal Society, is a Learned society for science that was founded in 1660 London ( ˈlʌndən is the capital and largest urban area in the United Kingdom.

Modern parachutes

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. Louis-Sébastien Lenormand ( May 25, 1757 – December 1837 was a French Physicist, Inventor and pioneer in parachuting This article is about the country For a topic outline on this subject see List of basic France topics. Lenormand also sketched it beforehand. Two years later, Jean-Pierre Blanchard demonstrated it as a means of safely disembarking from a hot air balloon. Jean-Pierre Blanchard (aka Jean Pierre François Blanchard was a French inventor most remembered as a pioneer in Aviation and ballooning. The hot air balloon is the oldest successful human-carrying Flight technology 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.

Subsequent development of the parachute focused on it becoming more compact. While the early parachutes were made of linen stretched over a wooden frame, in the late 1790s, Blanchard began making parachutes from folded silk, taking advantage of silk's strength and light weight. Linen is a Textile made from the Fibers of the Flax plant Linum usitatissimum. Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons In the Physical sciences weight is a Measurement of the gravitational Force acting on an object In 1797, André Garnerin made the first jump using such a parachute. Garnerin also invented the vented parachute, which improved the stability of the fall. In 1911, Gleb Kotelnikov invented the first knapsack parachute, later popularized by Paul Letteman and Kathchen Paulus. Gleb Yevgeniyevich Kotelnikov ( Котельников Глеб Евгеньевич in Russian, – November 22, 1944) was the Russian

At San Francisco in 1885, Thomas Scott Baldwin was the first person in the United States to descend from a balloon in a parachute. The City and County of San Francisco is the fourth most populous city Thomas Scott Baldwin ( June 30, 1860 &ndash May 17, 1923) was a U The United States of America —commonly referred to as the In 1911 Grant Morton made the first parachute jump from an airplane, in a Wright Model B, at Venice Beach, California. Venice is a district in western Los Angeles California. It is known for its Canals Beaches and Circus -like Ocean Front Walk, California ( is a US state on the West Coast of the United States, along the Pacific Ocean. The pilot of the plane was Phil Parmalee. Philip Orin Parmelee ( 1887 - 1 June, 1912) was an American aviation pioneer trained by the Wright brothers and credited with several early Morton's parachute was of the 'throw-out' type whereas he held the chute in his arms as he left the aircraft. On March 1, 1912, US Army Captain Albert Berry made the first parachute jump from a moving aircraft over Missouri using a 'pack' style chute. Events 86 BC - Lucius Cornelius Sulla, at the head of a Roman Republic army enters in Athens, removing the Tyrant Year 1912 ( MCMXII) was a Leap year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Leap year starting The United States of America —commonly referred to as the Captain Albert Berry is one of two people credited as the first person to make a successful Parachute jump from a powered aeroplane Overview Fixed-wing aircraft range from small training and recreational aircraft to Wide-body aircraft and military cargo aircraft. Missouri ( or) is a state in the Midwestern region of the United States bordered by Iowa, Illinois, Kentucky, Tennessee This is the style of chute that became en reg with the actual chute being stored or housed in a casing on the jumper's body. Štefan Banič from Slovakia invented the first actively used parachute, patenting it in 1913. Štefan Banič ( 23 November 1870 - 2 January, 1941) is the Inventor of the military Parachute and of the first actually Slovakia (long form Slovak Republic; Slovak:, long form, is a Landlocked country in Central Europe with a population of over five million On June 21, 1913 Georgia Broadwick became the first woman to parachute jump from a moving aircraft over Los Angeles. Events 524 - Godomar, King of the Burgundians defeats the Franks at the Battle of Vézeronce. Year 1913 ( MCMXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common Tiny Broadwick (born April 8 1893 in Oxford North Carolina &ndash died 1978 in California or Georgia Broadwick, was a pioneering parachutist. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West

The first military use for the parachute was for use by artillery spotters on tethered observation balloons in World War I. World War I Observation Balloon HD-SN-99-02269JPEG|200px|thumb|right|Close-up view of an American major in the basket of an observation balloon flying over territory near front lines during World World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All These were tempting targets for enemy fighter aircraft, though difficult to destroy, due to their heavy antiaircraft defenses. A fighter aircraft is a Military aircraft designed primarily for air-to-air combat with other Aircraft, as opposed to a Bomber, which is designed Anti-aircraft warfare, or air defense, is any method of engaging hostile military Aircraft in defence of ground objectives, ground or naval forces Because they were difficult to escape from, and dangerous when on fire due to their hydrogen inflation, observers would abandon them and descend by parachute as soon as enemy aircraft were seen. The ground crew would then attempt to retrieve and deflate the balloon as quickly as possible. No parachutes were issued to Allied "heavier-thatn-air" aircrew. ^[8] As a result, a pilot's only options were to ride his machine into the ground, jump from several thousand feet, or commit suicide using a standard-issued revolver (though the last two cases were only commonly practised by those who did not wish to die by burning). In the UK, Everard Calthrop, a railway engineer, and breeder of Arab horses, invented and marketed through his Aerial Patents Company a "British Parachute". Everard Richard Calthrop (1857 - 1927 was a British Railway Engineer and Inventor. The German air service, in 1918, became the world's first to introduce a standard parachute and the only one at the time. Despite Germany issuing their pilots with parachutes, their efficiency was relatively poor. As a result, many pilots died whilst using them, including aces such as Oberleutnant Erich Lowenhardt (who fell from 12,000 feet (3,700 m) after being accidentally rammed by a friendly) and Fritz Rumey (he tested it in 1918, only to have it fail from a little over 3,000 ft). Erich Loewenhardt ( April 7, 1897 - August 10, 1918) was the 3rd highest German Flying ace with 54 victories during

Tethered parachutes were initially tried but caused problems when the aircraft was spinning. In 1919 Leslie Irvin invented and successfully tested a parachute that the pilot could deploy when clear of the aircraft. Leslie Irvin may refer to Leslie Irvin (parachutist, a parachutist who made the first free-fall parachute jump Leslie Irvin (serial killer He became the first person to make a premeditated free-fall parachute jump from an airplane^[1].

An early brochure^[2] of the Irvin Air Chute Company credits William O'Connor 24 August 1920 at McCook Field near Dayton, Ohio as the first person to be saved by an Irvin parachute. Events 49 BC - Julius Caesar 's General Gaius Scribonius Curio is defeated in the Second Battle of the Bagradas River Year 1920 ( MCMXX) was a Leap year starting on Thursday (link will display 1920 of the Gregorian calendar McCook Field was an airfield and aviation experimentation station operated by the Aviation Section U Dayton is a city in southwestern Ohio, United States. It is the County seat and largest city of Montgomery County. Another life-saving jump was made at McCook Field by test pilot Lt. Harold H. Harris on Oct 20, 1922. Events 1740 - Maria Theresa takes the throne of Austria. France, Prussia, Bavaria and Saxony Year 1922 ( MCMXXII) was a Common year starting on Sunday of the Gregorian calendar. Shortly after Harris' jump two Dayton newspaper reporters suggested the creation of the Caterpillar Club for successful parachute jumps from disabled aircraft. The Caterpillar Club is an informal association of people who have successfully used a Parachute to bail out of a disabled aircraft Beginning with Italy in 1927, several countries experimented with using parachutes to drop soldiers behind enemy lines, and by World War II, large airborne forces were trained and used in surprise attacks. Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including Aircraft crew were routinely equipped with parachutes for emergencies as well.

Design

A parachute is made from thin, lightweight fabric, support tapes and suspension lines. The lines are usually gathered through cloth loops or metal connector links at the ends of several strong straps called risers. The risers in turn are attached to the harness containing the load. As the thin material inflates it increases drag and in turn slowing down the object it is carrying. The parachute successfully slows down the object enough so that it does not break on impact with the ground.

Deployment system

Types of parachutes

Round parachutes

Round parachutes, which are purely drag devices (that is, unlike the ram-air types, they provide no lift), are used in military, emergency and cargo applications. In the context of a Fluid flow relative to a body the lift force is the component of the Aerodynamic force that is Perpendicular to the flow These have large dome-shaped canopies made from a single layer of triangular cloth gores. A gore is a segment of a three-dimensional shape fabricated from a two- Dimensional material Some skydivers call them "jellyfish 'chutes" because they look like dome-shaped jellyfish. Modern sports parachutists rarely employ this style of parachute.

The first round parachutes were simple, flat circulars, but suffered from instability, so most military round parachutes are some sort of conical (i. e. cone-shaped) or parabolic (a flat circular canopy with an extended skirt) US Army T-10 parachute used for static-line jumps.

Round parachutes are designed to be steerable or non-steerable. Steerable versions are not as maneuverable as ram-air parachutes. An example of a steerable round is provided in the picture of the paratrooper's canopy; it is not ripped or torn but has a "T-U cut". This kind of cut allows air to escape from the back of the canopy, providing the parachute with limited forward speed. This gives the jumpers the ability to steer the parachute and to face into the wind to slow down the horizontal speed for the landing. The variables impact the way and the speed that the parachute falls, because it depends on the speed or the amount of force in the wind that might change how a parachute falls.

Cruciform (square) parachutes

The unique design characteristics of cruciform parachutes reduces oscillations and violent turns(swinging back and forth) 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 Advanced Tactical Parachute System (ATPS is a replacement Parachute system for the United States Army's T-10 system The ATPS canopy is a highly modified version of a cross/ cruciform platform and is square in appearance. The Advanced Tactical Parachute System (ATPS is a replacement Parachute system for the United States Army's T-10 system The ATPS (T-11) system will reduce the rate of descent by 30 percent from 21 feet per second (6. The Advanced Tactical Parachute System (ATPS is a replacement Parachute system for the United States Army's T-10 system 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.

Annular and pull-down apex parachutes

A variation on the round parachute is the pull down apex parachute—invented by a Frenchman named LeMogne—referred to as a Para-Commander-type canopy in some circles, after the first model of the type. It is a round parachute, but with suspension lines to the canopy apex that applies load there and pulls the apex closer to the load, distorting the round shape into a somewhat flattened or lenticular shape.

Often these designs have the fabric removed from the apex to open a hole through which air can exit, giving the canopy an annular geometry. They also have decreased horizontal drag due to their flatter shape, and when combined with rear-facing vents, can have considerable forward speed around 10 mph (15 km/h).

Ribbon and ring parachutes

Ribbon and ring parachutes have similarities to annular designs. They are frequently designed to deploy at supersonic speeds. For other uses see Supersonic. The term supersonic is used to define a speed that is over the Speed of sound ( Mach 1 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. Kevlar is the registered Trademark for a light strong para-aramid Synthetic fiber, related to other Aramids such as Nomex and The B61 Nuclear bomb is the primary Thermonuclear weapon in the U The B83 Nuclear weapon is a variable-yield Gravity bomb developed by the United States in the late 1970s entering service in 1983

Ram-air parachutes

Most modern parachutes are self-inflating "ram-air" airfoils known as a parafoil that provide control of speed and direction similar to paragliders. An airfoil (in American English) or aerofoil (in British English) is the shape of a Wing or blade (of a Propeller, rotor X-38 Ship -2 Landing on Lakebed EC99-45080-101-EDIT1jpg|thumb|200 px|The NASA X-38 prototype makes a gentle lakebed landing at the end of a July 1999 test flight at the Dryden Flight Research Paragliding is a recreational and competitive flying sport A paraglider is a free-flying foot-launched Aircraft. Paragliders have much greater lift and range, but parachutes are designed to handle, spread and mitigate the stresses of deployment at terminal velocity. A free falling object achieves its terminal velocity when the downward force of gravity ( Fg)equals the upward force of drag ( Fd) 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. Airlocks are one-way valves in the leading edge of the wing of a ram-air Parachute.

Personnel parachutes

Deployment

Reserve parachutes usually have a ripcord deployment system, which was first designed by Theodore Moscicki, but most modern main parachutes used by sports parachutists use a form of hand-deployed pilot chute. Ripcord is a part of a Skydiving harness-container system a handle attached to a steel cable ending in a closing pin A pilot chute is a small auxiliary Parachute used to deploy the main or reserve parachute A ripcord system pulls a closing pin (sometimes multiple pins), which releases a spring-loaded pilot chute, and opens the container; the pilot chute is then propelled into the air stream by its spring, then uses the force generated by passing air to extract a deployment bag containing the parachute canopy, to which it is attached via a bridle. 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.

Occasionally, a pilot chute does not generate enough force either to pull the pin or to extract the bag. Causes may be that the pilot chute is caught in the turbulent wake of the jumper (the "burble"), the closing loop holding the pin is too tight, or the pilot chute is generating insufficient force. This effect is known as "pilot chute hesitation," and, if it does not clear, it can lead to a total malfunction, requiring 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. A static line is a fixed cord attached to a large stable object

Varieties of personal ram-airs

Personal ram-air parachutes are loosely divided into two varieties: rectangular or tapered, commonly referred to as "squares" or "ellipticals" respectively. Medium-performance canopies (reserve-, BASE-, canopy formation-, and accuracy-type) are usually rectangular. BASE jumping is involving the use of a Parachute or the sequenced use of a Wingsuit and parachute to jump from fixed objects--with the parachute unopened at the jump High-performance, ram-air parachutes have a slightly tapered shape to their leading and/or trailing edges when viewed in plan form, and are known as ellipticals. Sometimes all the taper is in the leading edge (front), and sometimes in the trailing edge (tail).

Ellipticals are usually used only by sports parachutists. Ellipticals often have smaller, more numerous fabric cells and are shallower in profile. Their canopies can be anywhere from slightly elliptical to highly elliptical—indicating the amount of taper in the canopy design, which is often an indicator of the responsiveness of the canopy to control input for a given wing loading, and of the level of experience required to pilot the canopy safely.

The rectangular parachute designs tend to look like square, inflatable air mattresses with open front ends. They are generally safer to operate because they are less prone to dive rapidly with relatively small control inputs, they are usually flown with lower wing loadings per square foot of area, and they glide more slowly. They typically have a less-efficient glide ratio.

Wing loading of parachutes is measured similarly to that of aircraft: comparing the number of pounds (exit weight) to square footage of parachute fabric. Typical wing loadings for students, accuracy competitors, and BASE jumpers are less than one pound per square foot—often 0. 7 pounds per square foot or less. Most student skydivers fly with wing loadings below one pound per square foot. Most sport jumpers fly with wing loadings between 1. 0 and 1. 4 pounds per square foot, but many interested in performance landings exceed this wing loading. Professional Canopy pilots compete at wing loadings of 2 to 2. 6 pounds per square foot. While ram-air parachutes with wing loadings higher than four pounds per square foot have been landed, this is strictly the realm of professional test jumpers.

Smaller parachutes tend to fly faster for the same load, and ellipticals respond faster to control input. Therefore, small, elliptical designs are often chosen by experienced canopy pilots for the thrilling flying they provide. Flying a fast elliptical requires much more skill and experience. Fast ellipticals are also considerably more dangerous to land. With high-performance elliptical canopies, nuisance malfunctions can be much more serious than with a square design, and may quickly escalate into emergencies. Flying highly loaded, elliptical canopies is a major contributing factor in many skydiving accidents, although advanced training programs are helping to reduce this danger.

High-speed, cross-braced parachutes such as the Velocity, VX, XAOS and Sensei have given birth to a new branch of sport parachuting called "swooping. " A race course is set up in the landing area for expert pilots to measure the distance they are able to fly past the 6-foot (1. 8 m) tall entry gate. Current world records exceed 600 feet (180 m).

Aspect ratio is another way to measure ram-air parachutes. Aspect ratios of parachutes are measured the same way as aircraft wings, by comparing span with chord. Low aspect ratio parachutes (i. e. span 1. 8 times the chord) are now limited to precision landing competitions. Popular precision landing parachutes include Jalbert (now NAA) Para-Foils and John Eiff's series of Challenger Classics. While low aspect ratio parachutes tend to be extremely stable—with gentle stall characteristics—they suffer from steep glide ratios and small "sweet spots" for timing the landing flare.

Medium aspect ratio (i. e. 2. 1) parachutes are widely used for reserves, BASE, and canopy formation competition because of their predictable opening characteristics. Most medium aspect ratio parachutes have seven cells.

High aspect ratio parachutes have the flattest glide and the largest "sweet spots" (for timing the landing flare) but the least predictable openings. An aspect ratio of 2. 7 is about the upper limit for parachutes. High aspect ratio canopies typically have nine or more cells. All reserve ram-air parachutes are of the square variety, because of the greater reliability, and the less-demanding handling characteristics.

General characteristics of ram-airs

Main parachutes used by skydivers today are designed to open softly. Overly rapid deployment was an early problem with ram-air designs. The primary innovation that slows the deployment of a ram-air canopy is the slider; a small rectangular piece of fabric with a grommet near each corner. A slider is a small rectangular piece of fabric with a Grommet near each corner used to control the deployment of a "ram-air" Parachute. Grommets and eyelets are Metal, Plastic, or Rubber rings that are inserted into a hole made through another material Four collections of lines go through the grommets to the risers. During deployment, the slider slides down from the canopy to just above the risers. The slider is slowed by air resistance as it descends and reduces the rate at which the lines can spread. This reduces the speed at which the canopy can open and inflate.

At the same time, the overall design of a parachute still has a significant influence on the deployment speed. Modern sport parachutes' deployment speeds vary considerably. Most modern parachutes open comfortably, but individual skydivers may prefer harsher deployment.

The deployment process is inherently chaotic. Rapid deployments can still occur even with well-behaved canopies. On rare occasions deployment can even be so rapid that the jumper suffers bruising, injury, or death.

For example, one method of reducing the air-resistance of a reserves slider is to make it of open-mesh fabric.

Safety

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. 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 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. 3-ring release system is a Parachute component that is widely used by sport skydivers to attach the two risers of a main parachute to the harness that bears the load under the 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. Automatic Activation Device in Skydiving terminology refers to an electronic- pyrotechnic or mechanical device that automatically opens the main or reserve Parachute This page is about the Automatic Activation Device for parachutes

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. Probability is the likelihood or chance that something is the case or will happen 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.

Parachute malfunctions

Below are listed malfunctions specific to round-parachutes. For malfunctions specific to square parachutes, see Malfunction (parachuting). A malfunction is a partial or total failure of a parachuting device to operate as intended

A "Mae West" is a type of round parachute malfunction which contorts the shape of the canopy into the appearance of a brassiere, presumably one suitable for a woman of Mae West's proportions. Mae West (August 17 1893 &ndash November 22 1980 was an American actress, Playwright, Screenwriter, and Sex symbol. [3]

"Squidding" occurs when a parachute fails to inflate properly and its sides are forced inside the canopy. This kind of malfunction occurred during parachute testing for the Mars Exploration Rover. NASA 's Mars Exploration Rover ( MER) Mission is an ongoing robotic mission of exploring Mars, that began in 2003 with the sending of [4]

A "cigarette roll" occurs when a parachute deploys fully from the bag but fails to open. The parachute then appears as a vertical column of cloth (in the general shape of a cigarette), providing the jumper with very little drag. It is caused when one skirt of the canopy, instead of expanding outward, is blown against the opposite skirt. The column of nylon fabric, buffeted by the wind, rapidly heats from the friction of the nylon rubbing against nylon and can melt the fabric and fuse it together, preventing any hope of the canopy opening.

An "inversion" occurs when one skirt of the canopy blows between the suspension lines on the opposite side of the parachute and then catches air. That portion then forms a secondary lobe with the canopy inverted. The secondary lobe grows until the canopy turns completely inside out.

References

External links

• The 2nd FAI World Championships in Canopy Piloting - 2008 at Pretoria Skydiving Club South Africa
• Parachute History
• FAI The Federation Aeronautique Internationale -- The international governing body for all airborne sports.
• USPA The United States Parachute Association -- The governing body for sport skydiving in the U. S.
• CSPA The Canadian Sport Parachuting Association -- The governing body for sport skydiving in Canada.
• Parachute
• Skydiving education
• Details of the highest parachute jump ever. Excelsior III free-fall from a Stratospheric Balloon

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