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Parachuting & Aviation Supplies
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag.The parachute was invented in 1783 by Sébastien Lenormand . Parachutes are normally used to slow the descent of a person or object to Earth or another celestial body within an atmosphere. 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 freefall, or space shuttle after touchdown). 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. But older style parachutes were little more than cloth and sticks. The design has changed considerably over the years from roughly cut shapes to aero-dynamic ram parachutes. Although skydiving can have its thrills and excitements, it can be very dangerous too. 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 the parachute will have to be replaced because it will cease to perform properly and 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.
Early forms
In the 9th century, an Arab Muslim daredevil named Armen Firman jumped from a tower in Córdoba using a loose cloak stiffened with wooden struts to arrest his fall with only minor injuries. In China rigid parasols were used for entertainment, allowing people to jump from high places and float to the ground. A conical parachute appears for the first time in the 1470s in an anonymous Italian manuscript, slightly preceding Leonardo da Vinci's conical parachute designs.[1] 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. The first successful test of a parachute was made in 1617 in Venice by the Dalmatian inventor Faust Vrančić which he named Homo Volans (Flying Man). Modern parachutesThe modern parachute was invented in 1783 by Sébastien Lenormand in France. Lenormand also skechted it before hand. 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. 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. 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. At San Francisco in 1885, Thomas Scott Baldwin was the first person in the United States to descend from a balloon in a parachute. In 1911 Grant Morton made the first parachute jump from an airplane, in a Wright Model B, at Venice Beach, California. The pilot of the plane was Phil Parmalee. 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. 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. On June 21, 1913 Georgia Broadwick became the first woman to parachute jump from a moving aircraft over Los Angeles. The first military use for the parachute was for use by artillery spotters on tethered observation balloons in World War I. These were tempting targets for enemy fighter aircraft, though difficult to destroy, due to their heavy antiaircraft defenses. 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. Allied aircraft crews, however, were forbidden from carrying their own parachutes. It was believed to encourage a lack of nerve in action. As well, early parachutes were very heavy, and fighters lacked the performance to carry the additional load through most of WWI. As a result, a pilot's only options were to ride their 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 practiced by those who did not wish to die by burning). In the UK, Everard Richard Calthrop, a railway engineer, and breeder of Arab horses, invented and marketed through his Aerial Patents Company a "British Parachute". 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 parachutes, many setbacks were forced upon them. 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 1917, only to have it fail from a little over 3,000 ft). 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. He became the first person to make a premeditated freefall parachute jump from an airplane Airborne Systems. An early brochure [1] 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. Another life-saving jump was made at McCook Field by test pilot Lt. Harold H. Harris on Oct 20, 1922. Shortly after Harris' jump two Dayton newspaper reporters suggested the creation of the Caterpillar Club for successful parachute jumps from 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. Aircraft crew were routinely equipped with parachutes for emergencies as well, DesignA 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 systemsTypes of parachutesRound 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. These have large dome-shaped canopies made from a single layer of triangular cloth gores. Some skydivers call them "jellyfish 'chutes" because they look like dome-shaped jellyfish. Modern 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) parachutesThe unique design characteristics of cruciform parachutes reduces oscillations (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 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 25 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. Annular and pull-down apex parachutesA 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 parachutesRibbon 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. Ram-air parachutesMost 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. Personnel parachutes
ReservesParatroopers and parachutists carry two parachutes. The primary parachute is called a main parachute, the secondary is called a reserve parachute. The jumper uses the reserve if the main parachute fails to deploy or operate correctly. Reserve parachutes were introduced in World War II by the US Army paratroopers, and are now almost universal. For civilian jumpers, the only exceptions are BASE jumping parachutes and emergency bail-out rigs, which both have a single parachute. These emergency parachutes tended to be of round design in the past, while modern PEPs (e.g., P124A/Aviator) contain the large, docile ram-air type. DeploymentReserve 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. 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. Varieties of personal ram-airsPersonal 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. 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-airsMain 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. 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 reserve's slider is to make it of open-mesh fabric. SafetyA 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. Parachute malfunctionsBelow are listed malfunctions specific to round-parachutes. For malfunctions specific to square parachutes, see Malfunction (parachuting). 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. [2] "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. [3] 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
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Parachuting is an activity involving a preplanned drop from a height using a deployable parachute. One type of parachuting is skydiving, which is recreational parachuting, also called sport parachuting. The history of parachuting is not clear. It's known that Andre-Jacques Garnerin made successful parachute jumps from a hot-air balloon in 1797. The military developed parachuting technology first as a way to save aircrews from emergencies aboard balloons and aircraft in flight, later as a way of delivering soldiers to the battlefield. Early competitions date back to the 1930s, and it became an international sport in 1951. Today it is performed as a recreational activity and a competitive sport, as well as for the deployment of military personnel Airborne forces and occasionally forest firefighters.
ProcedureTypically, a trained skydiver (or jumper) and a group of associates meet at an isolated airport, sometimes referred to as a "drop zone." A fixed base operator at that airport usually operates one or more aircraft, and takes groups of skydivers up for a fee. In the earlier days of the sport, it was common for an individual jumper to go up in a Cessna light aircraft such as C-172 or C-185. Larger DZ's near populated areas might use larger aircraft such as the Beech 18 or Douglas DC-3 aircraft for reasons of economy. 
A typical jump involves individuals jumping out of aircraft (usually an airplane, but sometimes a helicopter or even the gondola of a balloon), travelling at approximately 4000 metres (around 13,000 feet) altitude, and free-falling for a period of time before activating a parachute to slow the landing down to safe speeds. 
Once the parachute is opened, (usually the parachute will be fully inflated by 2,500 ft). the jumper can control his or her direction and speed with cords called "steering lines," with hand grips called "toggles" that are attached to the parachute, and so he or she can aim for the landing site and come to a relatively gentle stop in a safe landing environment. Most modern sport parachutes are self-inflating "ram-air" wings that provide control of speed and direction similar to the related paragliders. (Purists in either sport would note that paragliders have much greater lift and range, but that parachutes are designed to absorb the stresses of deployment at terminal velocity.) By manipulating the shape of the body, as a pilot manipulates the shape of his aircraft's wings, turns, forward motion, backwards motion, and even lift can be generated. Experienced skydivers will tell someone that in freefall, one can do anything a bird can do, except go back up. Skydivers generally do not experience a "falling" sensation due to the fact that the resistance of the air to their body at speeds above about 50 MPH provides some feeling of weight and direction. At normal exit speeds for aircraft (approx 90 MPH) there is little feeling of falling just after exit, but jumping from a balloon or helicopter can create this sensation. They reach terminal velocity (around 120 mph (190 km/h) for belly to Earth orientations, 150-200 mph (240-320 km/h) for head down orientations) and are no longer accelerating towards the ground. At this point the sensation is as of a hard wind. When they leave the plane, their momentum from the plane causes their direction of travel to change from the direction of the airplane's flight (horizontal) to the direction pulled by the force of gravity (vertical). Skydivers call this transition period "the hill", and the amount of distance they fly with the plane due to the momentum is called "forward throw". For typical people, less than 1g of force along the body's long axis is what causes the "stomach in your throat" feeling on a roller-coaster or other amusement park rides. Most skydivers make their first jump with an experienced and trained instructor (this type of skydive may be in the form of a tandem skydive). During the tandem jump the jumpmaster is responsible for the stable exit, maintaining a proper stable freefall position, and activating and controlling the parachute. With training and experience, the fear of the first few jumps is supplanted by the tact of controlling fear so that one may come to experience the satisfaction of mastering aerial skills and performing increasingly complicated maneuvers in the sky with friends. Other training methods include static line, IAD (Instructor Assisted Deployment), and AFF (Accelerated Free-Fall) aka Progressive Free-Fall (PFF) in Canada. At larger dropzones, mostly in the Sun Belt region of the United States, training in the sport is often conducted by full-time instructors and coaches at commercial establishments. Commercial centers often provide year-round availability, larger aircraft, and staff who are current in both their sport and their instructional skills. 
In the other latitudes, where winter (or monsoons) gets in the way of year-round operation, commercial skydiving centers are less prevalent and much of the parachuting activity is carried on by clubs. These clubs tend to support smaller aircraft. Training may be offered (by instructors who are tested and certified in exactly the same way as their commercial counterparts) in occasional classes or as demand warrants. These clubs tend to be weekend only operations as the majority of the staff have full-time jobs during the week. Club members will often visit larger centers for holidays, events, and for some concentrated exposure to the latest techniques. Skills
Parachuting has complex skills that can take thousands of jumps to master, but the basics are often fully understood and useful during the first few jumps. There are four basic areas of skill: basic safety, free fall maneuvers, parachute operation, and landing. Free-fall maneuversIn freefall most skydivers start by learning to maintain a stable belly to earth "arch" position[1]. In this position the average fall rate is around 190 km/h (120 mph). Learning a stable arch position is a basic skill essential for a reliable parachute deployment. Next, jumpers learn to move or turn in any direction while remaining belly to earth. Using these skills a group of jumpers can create sequences of formations on a single jump, a discipline known as relative work (RW). In the late 1980s more experienced jumpers started experimenting with freeflying, falling in any orientation other than belly to earth. Today many jumpers start freeflying soon after they earn their license, bypassing the RW (deployment-position flying) stepping stone. Parachute operation and landingThe decision of when to deploy the parachute is a matter of safety. A parachute should be deployed sufficiently high to give the parachutist time to handle a malfunction, should one occur. 600 metres (1,970 ft) is the practical minimum for advanced skydivers.[2] Skydivers monitor their altimeters during freefall to decide when to break off from the formation (if applicable) and when to open their parachutes. Many skydivers open higher to practice their parachute flying skills. During a "hop-and-pop", a jump in which the parachute is deployed immediately upon exiting the aircraft, it is not uncommon to be under canopy as high as 1200 to 1500 meters (4000 to 5000 ft). 
Parachute flying involves two basic challenges. Firstly to avoid injury and secondly to land where planned, often on a designated target. Some experienced skydivers enjoy performing aerobatic maneuvers with parachutes, the most notable being the "Swoop". This is a thrilling, but dangerous maneuver entailing a steep, high speed landing approach, before leveling off a couple of feet above the ground to maintain a fast glide parallel to the surface. Swoops as far as 180 metres (590 ft) have been achieved. A modern parachute or canopy "wing" can glide substantial distances. Elliptical canopies go faster and farther, and some small, highly loaded canopies glide faster than a man can run, which can make them very challenging to land. A highly experienced skydiver using a very small canopy can achieve over 100 km/h (60 mph) horizontal speeds in landing. Today, the majority of skydiving related injuries happen under a fully opened and functioning parachute. The most common causes being poorly-executed, radical maneuvers near to the ground, such as hook turns, or landing flares performed either too high or too low. SafetyDespite the perception of danger, fatalities are rare. However, each year a number of people are hurt or killed parachuting world-wide.[3][4] About 30 skydivers are killed each year in the US; roughly one death for every 100,000 jumps.[5] In the US and in most of the western world skydivers are required to carry a second reserve parachute which has been inspected and packed by a certificated parachute rigger (in the US, an FAA certificated parachute rigger). Many skydivers use an automatic activation device (AAD) that opens the reserve parachute at a safe altitude in the event of failing to activate the main canopy themselves. Most skydivers wear a visual altimeter, but some go as far as using audible altimeters as well. In recent years, one of the most common sources of injury is a low turn under a high-performance canopy and while swooping. Swooping is the advanced discipline of gliding parallel to the ground during landing. Changing wind conditions are another risk factor. In conditions of strong winds, and turbulence during hot days the parachutist can be caught in downdrafts close to the ground. Shifting winds can cause a crosswind or downwind landing which have a higher potential for injury due to the wind speed adding to the landing speed. Equipment failure rarely causes fatalities and injuries. While approximately one in 600 jumps results in a main parachute malfunction, reserve canopies are packed by an FAA licensed rigger and are designed to be highly reliable. Parachuting disciplines such as BASE jumping or those that involve equipment such as wing suit flying and sky surfing have a higher risk factor due to the lower mobility of the jumper and the greater risk of entanglement. For this reason these disciplines are generally practiced by experienced jumpers. It is worth noting that depictions in commercial films — notably Hollywood action movies — usually understate the dangers of the sport. Often, the characters in such films are shown performing feats that are physically impossible without special effects assistance. In other cases, their practices would cause them to be grounded or shunned at any safety-conscious drop zone or club. USPA member drop zones in the US and Canada are required to have an experienced jumper act as a "safety officer" (in Canada DSO - Drop Zone Safety Officer; in the U.S. S&TA - Safety and Training Advisor) who is responsible for dealing with the jumpers who violate rules, regulations, or otherwise act in a fashion deemed unsafe by the appointed individual. In many countries, either the local regulations or the liability-conscious prudence of the dropzone owners require that parachutists must have attained the age of majority before engaging in the sport. TypesThere are several different disciplines to embrace within parachuting. Each of these is enjoyed by both the recreational (weekend) and the competitive participants. There is even a small group of professionals who earn their living with parachuting. They win competitions having cash prizes or are employed or sponsored by skydiving related manufacturers. Parachutists can participate both in competitive and in purely recreational skydiving events. World championships are held regularly in locations offering flat terrain and clear skies. An exception is Paraski, where winter weather and ski-hill terrain are required. Types of parachuting include:
Training
There are ways to practice different aspects of skydiving, without actually jumping. Vertical wind tunnels can be used to practice skills for free fall ("indoor skydiving" or "bodyflight"), while virtual reality parachute simulators can be used to practice parachute control. Beginning skydivers seeking training have a few different options available to them: A unique program where students accomplish their very first jump as a solo freefall is offered at the United States Air Force Academy. The program is called AM490, one in a series of airmanship courses at the school. While typically open only to cadets, Winfield W. Scott Jr., the school's superintendent, went through this program when he was nearly 60 years old. Parachute deploymentAt a skydiver's designated deployment-altitude; the individual pulls the pilotchute from a pocket at the bottom of the rig (the backpack-like container holding both parachutes, a.k.a. canopies). This is known as a bottom of container (B.O.C.) deployment system. This small parachute is connected to the main parachute by a line known as the "bridle" which feeds through a grommet on a small bag - the deployment bag (or d-bag) which has the folded parachute inside and the lines stowed in rubber bands across the top. At the bottom of the container's tray which holds the main parachute is a loop which, in the closing sequence of the parachute system, is fed through grommets on each of four flaps that closes the container. Attached to the bridle is a curved pin which is inserted through the closing loop after it has been fed through each of these grommets. When the pilotchute is thrown out, it catches the wind and pulls the pin out of the closing loop, releasing the deployment bag from the container worn by the skydiver (who is ideally in the stable belly-towards-earth arched position). The parachute lines are pulled loose from rubber bands, through which they were stowed during packing, and extend as the canopy starts to open. To reduce the risk of injury, a rectangular piece of fabric called the "slider" (which separates the parachute lines into four main groups fed through grommets in the four respective corners of the slider) slows the opening of the parachute and works its way down until the canopy is fully open and the slider is just above the head of the skydiver. During a normal deployment, a skydiver will generally experience a few seconds of intense deceleration, in the realm of 3 to 4 G's, while the parachute slows the descent from 120 mph (190 km/h) to approximately 12 mph (19 km/h). If a skydiver experiences a malfunction with their main parachute which they cannot correct, they have a "cut-away" handle on the front right-hand side of their harness (on the chest) which will release the main canopy from the harness/container. Once free from the malfunctioning main canopy, the reserve canopy can be activated by pulling a second handle on the front left (sometimes triggered by a Reserve Static Line (RSL) which, if present, opens the reserve container and allow the spring loaded pilotchute to extract the Reserve Canopy located in the top of the container immediately after the main is cut away). A new type of RSL has been developed called the Skyhook. This new system uses the "cut-away" main canopy to act as a very large pilot chute to more quickly extract the reserve canopy. The Skyhook is an incredibly fast system that has the jumper under the reserve canopy and flying within 2 seconds (compared to the 2-5 seconds of the old system). VariationsIn addition to the various disciplines, for which people actually train, purchase specialized equipment and get coaching, the recreational skydiver finds ways to just have fun. Hit and rockOne example of this is "Hit and Rock", which is a variant of Accuracy landing devised to let people of varying skill levels "compete" for fun, while spoofing the age and abilities of some participants. "Hit and Rock" is originally from POPS (Parachutists Over Phorty Society). See the POPS Main site The object now becomes: to land as close as possible to the chair, remove the parachute harness, sprint to the chair, sit fully in the chair and rock back and forth at least one time. The contestant is timed from the moment that feet touch the ground until that first rock is completed. This event is considered a race. Pond swoopingPond swooping is a form of competitive parachuting wherein canopy pilots attempt to touch down at a glide across a small body of water, and onto the shore. Events provide lighthearted competition, rating accuracy, speed, distance and style. Points and peer approval are reduced when a participant "chows," or fails to reach shore and sinks into the water. Swoop and Chug the BeerVery similar to Hit and Rock, except the target is replaced by a case of beer. Each jumper is timed from the moment his feet touch the ground until he "chugs," or rapidly drinks the can of beer and places the empty can upside-down on his head. Of course, it must be mentioned that dropzones enforce strict rules prohibiting anyone from jumping any more that day once alcohol has been consumed. Therefore, the Swoop & Chug (aka Hit & Chug) is usually reserved for the last load of the day. Cross-CountryA cross-country jump refers to a skydive where the participants open their parachutes immediately after jumping, with the intention of covering as much ground under canopy as possible. Usual distance from Jump Run to the DZ is 10 miles (20 km). Camera flyingIn camera flying, a cameraman or camerwoman jumps with other skydivers and films them. The camera flyer often wears specialized equipment, such as a winged jumpsuit to provide a greater range of fallrates, helmet-mounted video and still cameras, mouth operated camera switches, and special optical sights. Some skydivers specialize in camera flying and a few earn significant fees for filming students on coached jumps or tandem-jumpers, or producing professional footage and photographs for the media. There is always a demand for good camera flyers in the skydiving community, as many of the competitive skydiving disciplines are judged from a video record. Night jumpsSkydiving is not always restricted to daytime hours. Experienced skydivers sometimes perform night jumps. For obvious safety reasons, this requires more equipment than a usual daytime jump and in most jurisdictions requires both an advanced skydiving license (at least a B-License in the U.S.) and specialized training (night rating). A lighted altimeter (preferably accompanied with an audible altimeter) is a must. Skydivers performing night jumps often take flashlights up with them so that they can check their canopies once they deploy, so they can be assured that the canopy has opened correctly and is safe to fly and land. Visibility to other skydivers and other aircraft is also a consideration; FAA regulations require skydivers jumping at night to be wearing a light visible for three miles (5 km) in every direction, and to turn it on once they are under canopy. Stuff jumps
Skydivers are always looking for something new to do in the air. With the availability of a rear door aircraft and a large, unpopulated space to jump over, 'stuff' jumps become possible. In these jumps the skydivers jump out with some object. Rubber raft jumps are popular, where the jumpers sit in a rubber raft. Cars, bikes, motorcycles, water tanks and inflatable companions have also been thrown out the back of an aircraft. At a certain height the jumpers break off from the object and deploy their parachutes, leaving it to crash into the ground at a very high speed. Parachuting organizationsNational parachuting associations exist in many countries (many affiliated with the Fédération Aéronautique Internationale (FAI)), to promote their sport. In most cases, national representative bodies, as well as prudent local dropzone operators, require that participants carry certification, attesting to their training, their level of experience in the sport, and their proven competence. Anyone who cannot produce such bona-fides is treated as a student, requiring close supervision. The primary organization in the United States is the United States Parachute Association (USPA)[1]. This organization hands out licenses and ratings for all American skydiving activities based on safety qualifications. The USPA governs safety in the sport of skydiving as this is the organizations sole responsibility and also publishes the Skydivers Information Manual (SIM) and many other resources. In Canada, the Canadian Sport Parachuting Association is the lead organization. In South Africa the sport is managed by the Parachute Association of South Africa. Within the sport, associations promote safety, technical advances, training-and-certification, competition and other interests of their members. Outside their respective communities, they promote their sport to the public, and often intercede with government regulators. Competitions are organized at regional, national and international levels in most these disciplines. Some of them offer amateur competition. Many of the more photogenic/videogenic variants also enjoy sponsored events with prize money for the winners. The majority of jumpers tend to be non-competitive, enjoying the opportunity to "get some air" with their friends on weekends and holidays. The atmosphere of their gatherings is relaxed, sociable and welcoming to newcomers. Party events, called "boogies" are arranged at local, national and international scale, each year, attracting both the enthusiastic young jumpers and many of their elders -- Parachutists Over Phorty (POPs), Skydivers Over Sixty (SOS) and even older groups who have yet to choose a catchy name for themselves. Famous people associated with this sport include Valery Rozov, a gold medalist from the 1998 X Games, who has had more than 1,500 jumps. Georgia Thompson("Tiny") Broadwick is one of the first American skydivers, and she made the first freefall. 
Drop zone traditions and cultureDrop zones often have distinct cultures or traditions and there are many skydiving traditions that are practiced at drop zones all over the world. Most drop zones have a "beer line", a perimeter around the landing area which marks where it becomes unsafe to land. When an experienced skydiver crosses over the beer line when landing or if their parachute crosses over the beer line they are required by tradition to buy a case of beer for the other experienced skydivers at the drop zone. Other events often prompt beer buying. For instance when an A license is achieved the licensee is expected to buy a case of beer for other experienced skydivers for them to get to know each other over. Also saying the word "first" after your first static line jump prompts the offender to buy a case of beer. Often the beer tally is announced over the loud speakers from the manifest. Often on the weekends experienced skydivers party and drink the owed beers in the hangar or around a bonfire sometimes musicians are brought in for more busy times of the year especially during Boogies. Boogies are huge jumping parties that often last a few days and evolve entertainment and special food at night and special skydiving events during the day. It is important to know that beer drinking activities are kept strictly separate from jumping activities and skydivers are mostly acutely conscious of safety. Other traditions include wearing jumpsuits with particularly bright colors and bold designs along with eye catching parachutes. It is tradition that when one archives 100 jumps they are pied and thrown in the swooping pond by their experienced skydiver friends. Among skydivers it is common to make jokes about jumping out of a 'perfectly good airplane.' It is common for many instructors and skydiving enthusiasts to camp out at the drop zone promoting these traditions. Many skydivers enjoy playing footbag when the weather doesn't permit jumping. A common description of hackysack by skydivers is "a game played with a ball that doesn't bounce by people who might." While there isn't an official code of ethics among skydivers many follow some unwritten rules. It is common for skydivers to be very generous. Skydiving is a dangerous sport and because of that unwritten rules are very important to skydivers. EquipmentCosts in the sport are not trivial. As new technological advances or performance enhancements are introduced, they tend to nudge equipment prices higher. Similarly, the average skydiver carries more equipment than in earlier years, with safety devices (such as an Reserve static line) contributing a significant portion of the cost. A full set of brand-new equipment can easily cost as much as a new motorcycle or half a small car. The market is not large enough to permit the commoditization and price-erosion that is seen in other technologically intensive industries (like the computer industry). In many countries, the sport supports a substantial used-equipment market. For many beginners, especially those with limited funds, that is the preferred way to acquire "gear", and has two advantages:
Novices generally start with parachutes that are large and docile relative to the jumper's body-weight. As they improve in skill and confidence, it is customary to graduate to smaller, faster, more responsive parachutes. An active jumper might change parachute canopies several times in the space of a few years, while retaining his or her first harness/container and peripheral equipment. Older jumpers, especially those who jump only on weekends in summer, sometimes tend in the other direction, selecting slightly larger, more gentle parachutes that do not demand youthful intensity and reflexes on each jump. They may be adhering to the maxim that: "There are old jumpers and there are bold jumpers, but there are no old, bold jumpers." Most parachuting equipment is ruggedly designed and is enjoyed by several owners before being retired. Purchasers are always advised to have any potential purchases examined by a qualified parachute rigger. A rigger is trained to spot signs of damage or misuse. Riggers also keep track of industry product and safety bulletins, and can therefore determine if a piece of equipment is up-to-date and serviceable. Parachuting records
See alsoNotes
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