A parachute is a device used to slow the motion of an object through an atmosphere by creating drag (or in the case of ram-air parachutes, aerodynamic lift). Parachutes are usually made out of light, strong fabric, originally silk, now most commonly nylon. They are typically dome-shaped, but vary, with rectangles, inverted domes, and others found. A variety of loads are attached to parachutes, including people, food, equipment, space capsules, and bombs.
In fluid dynamics, drag is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers or a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, drag forces depend on velocity. Drag force is proportional to the velocity for a laminar flow and the squared velocity for a turbulent flow. Even though the ultimate cause of a drag is viscous friction, the turbulent drag is independent of viscosity.
A fluid flowing past the surface of a body exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it can act in any direction at right angles to the flow.
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles, thus producing different colors.
A drogue chute is used to aid horizontal deceleration of a vehicle including fixed-wing aircraft and drag racers, provide stability, as to assist certain types of light aircraft in distress,tandem free-fall; and as a pilot triggering deployment of a larger parachute.
A fixed-wing aircraft is a flying machine, such as an airplane or aeroplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft, and ornithopters. The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft and aeroplanes that use wing morphing are all examples of fixed-wing aircraft.
Drag racing is a type of motor racing in which automobiles or motorcycles compete, usually two at a time, to be first to cross a set finish line. The race follows a short, straight course from a standing start over a measured distance, most commonly 1⁄4 mi, with a shorter becoming increasingly popular, as it has become the standard for Top Fuel dragsters and funny cars, where some major bracket races and other sanctioning bodies have adopted it as the standard, while the 1⁄8 mi is also popular in some circles. Electronic timing and speed sensing systems have been used to record race results since the 1960s.
A light aircraft is an aircraft that has a maximum gross takeoff weight of 12,500 lb (5,670 kg) or less.
The earliest fictional account of a parachute type of device was made some 4,000 years ago when the Chinese noticed that air resistance would slow a person's fall from a height. The Western Han Dynasty writer Sima Qian in his book Historical Records recounts the story of Shun, a legendary Chinese emperor who ran away from his murderous father by climbing onto the top of a high granary. As there was nowhere to go, Shun grabbed two bamboo hats and leaped off and glided downward to safety.
Sima Qian was a Chinese historian of the early Han dynasty. He is considered the father of Chinese historiography for his Records of the Grand Historian, a Jizhuanti-style general history of China, covering more than two thousand years from the Yellow Emperor to his time, during the reign of Emperor Wu of Han, a work that had much influence for centuries afterwards on history-writing not only in China, but in Korea, Japan and Vietnam as well. Although he worked as the Court Astrologer, later generations refer to him as the Grand Historian for his monumental work; a work which in later generations would often only be somewhat tacitly or glancingly acknowledged as an achievement only made possible by his acceptance and endurance of punitive actions against him, including imprisonment, castration, and subjection to servility.
The Records of the Grand Historian, also known by its Chinese name Shiji, is a monumental history of ancient China and the world finished around 94 BC by the Han dynasty official Sima Qian after having been started by his father, Sima Tan, Grand Astrologer to the imperial court. The work covers the world as it was then known to the Chinese and a 2500-year period from the age of the legendary Yellow Emperor to the reign of Emperor Wu of Han in the author's own time.
The earliest evidence for the modern 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 crossbar frame attached to a conical canopy. As a safety measure, four straps ran from the ends of the rods to a waist belt, 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 first design appears to be too small to be effective and the wooden frame is superfluous and potentially harmful, the basic concept of a working parachute is apparent.
The Renaissance is a period in European history, covering the span between the 14th and 17th centuries and marking the transition from the Middle Ages to modernity. The traditional view focuses more on the early modern aspects of the Renaissance and argues that it was a break from the past, but many historians today focus more on its medieval aspects and argue that it was an extension of the middle ages.
Shortly after, 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 learned 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 Briton Adrian Nicholas and again in 2008 by the Swiss skydiver Olivier Vietti-Teppa. 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."
A polymath is a person whose expertise spans a significant number of subject areas, known to draw on complex bodies of knowledge to solve specific problems.
Leonardo di ser Piero da Vinci, more commonly Leonardo da Vinci or simply Leonardo, was an Italian polymath of the Renaissance whose areas of interest included invention, drawing, painting, sculpting, architecture, science, music, mathematics, engineering, literature, anatomy, geology, astronomy, botany, writing, history, and cartography. He has been variously called the father of palaeontology, ichnology, and architecture, and he is widely considered one of the greatest painters of all time. Sometimes credited with the inventions of the parachute, helicopter, and tank, he epitomised the Renaissance humanist ideal.
The Codex Atlanticus is a twelve-volume, bound set of drawings and writings by Leonardo da Vinci, the largest such set; its name indicates the large paper used to preserve original da Vinci notebook pages, which was that used for atlases. It comprises 1,119 leaves dating from 1478 to 1519, the contents covering a great variety of subjects, from flight to weaponry to musical instruments and from mathematics to botany. This codex was gathered by the sculptor Pompeo Leoni, son of Leone Leoni, in the late 16th century, who dismembered some of Leonardo's notebooks in its formation. It is currently preserved at the Biblioteca Ambrosiana in Milan.
The Croatian polymath and inventor Fausto Veranzio (1551–1617) examined da Vinci's parachute sketch and kept the square frame but replaced the canopy with a bulging sail-like piece of cloth that he came to realize decelerates a fall more effectively.A now-famous depiction of a parachute that he dubbed Homo Volans (Flying Man), showing a man parachuting from a tower, presumably St Mark's Campanile in Venice, appeared in his book on mechanics, Machinae Novae ("New Machines", published in 1615 or 1616), alongside a number of other devices and technical concepts.
Fausto Veranzio was a Croatian polymath and bishop from Šibenik, then part of the Venetian Republic and today part of Croatia.
St Mark's Campanile is the bell tower of St Mark's Basilica in Venice, Italy, located in the Piazza San Marco. It is one of the most recognizable symbols of the city.
Venice is a city in northeastern Italy and the capital of the Veneto region.
It was once widely believed that in 1617, Veranzio, then aged 65 and seriously ill, implemented his design and tested the parachute by jumping from St Mark's Campanile,from a bridge nearby, or from St Martin's Cathedral in Bratislava. In various publications it was incorrectly claimed the event was documented some thirty years later by John Wilkins, founder and secretary of the Royal Society in London, in his book Mathematical Magick or, the Wonders that may be Performed by Mechanical Geometry , published in London in 1648. However, Wilkins wrote about flying, not parachutes, and does not mention Veranzio, a parachute jump, or any event in 1617. Doubts about this test, which include a lack of written evidence, suggest it never occurred, and was instead a misreading of historical notes.
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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 his device beforehand.
Two years later, in 1785, Lenormand coined the word "parachute" by hybridizing an Italian prefix para, an imperative form of parare = to avert, defend, resist, guard, shield or shroud, from paro = to parry, and chute, the French word for fall, to describe the aeronautical device's real function.
Also in 1785, 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 claimed to have had the opportunity to try it himself in 1793 when his hot air balloon ruptured and he used a parachute to descend (this event was not witnessed by others).
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 descent of a "frameless" parachute covered in silk.In 1804 Jérôme Lalande introduced a vent in the canopy to eliminate violent oscillations.
In 1907 Charles Broadwick demonstrated two key advances in the parachute he used to jump from hot air balloons at fairs: he folded his parachute into a pack he wore on his back and the parachute was pulled from the pack by a static line attached to the balloon. When Broadwick jumped from the balloon, the static line became taut, pulled the parachute from the pack, and then snapped.
In 1911 a successful test took place with a dummy at the Eiffel tower in Paris. The puppet's weight was 75 kg; the parachute's weight was 21 kg. The cables between puppet and the parachute were 9 m long. On February 4, 1912, Franz Reichelt jumped to his death from the tower during initial testing of his wearable parachute.
Also in 1911, Grant Morton made the first parachute jump from an airplane, a Wright Model B piloted by Phil Parmalee, at Venice Beach, California. Morton's device was of the "throw-out" type where he held the parachute in his arms as he left the aircraft. In the same year, Russian Gleb Kotelnikov invented the first knapsack parachute,although Hermann Lattemann and his wife Käthe Paulus had been jumping with bagged parachutes in the last decade of the 19th century.
In 1912, on a road near Tsarskoye Selo, years before it became part of St. Petersburg, Kotelnikov successfully demonstrated the braking effects of a parachute by accelerating a Russo-Balt automobile to its top speed and then opening a parachute attached to the back seat, thus also inventing the drogue parachute.
On March 1, 1912, U.S. Army Captain Albert Berry made the first (attached-type) parachute jump in the United States from a fixed-wing aircraft, a Benoist pusher, while flying above Jefferson Barracks, St. Louis, Missouri. The jump utilized a knapsack style parachute stored or housed in a casing on the jumper's body.
Štefan Banič, an immigrant in the United States, from Slovakia patented an umbrella-like design in 1914 [ clarification needed ]and sold (or donated) the patent to the United States military which later on modified his design, resulting in the first military parachute. Stefan Banic had been the first person to patent the parachute. Stefan Banic's design was the first to properly function in the 20th century.
On June 21, 1913, Georgia Broadwick became the first woman to parachute-jump from a moving aircraft, doing so over Los Angeles, California.In 1914, while doing demonstrations for the U.S. Army, Broadwick deployed her chute manually, thus becoming the first person to jump free-fall.
The first military use of the parachute was by artillery observers on tethered observation balloons in World War I. These were tempting targets for enemy fighter aircraft, though difficult to destroy, due to their heavy anti-aircraft defenses. Because it was difficult to escape from them, 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. The main part of the parachute was in a bag suspended from the balloon with the pilot wearing only a simple waist harness attached to the main parachute. When the balloon crew jumped the main part of the parachute was pulled from the bag by the crew's waist harness, first the shroud lines, followed by the main canopy. This type of parachute was first adopted on a large scale for their observation balloon crews by the Germans, and then later by the British and French. While this type of unit worked well from balloons, it had mixed results when used on fixed-wing aircraft by the Germans, where the bag was stored in a compartment directly behind the pilot. In many instances where it did not work the shroud lines became entangled with the spinning aircraft. Although a number of famous German fighter pilots were saved by this type of parachute, including Hermann Göring,no parachutes were issued to Allied "heavier-than-air" aircrew, since it was thought at the time that if a pilot had a parachute he would jump from the plane when hit rather than trying to save the aircraft.
Airplane cockpits at that time also were not large enough to accommodate a pilot and a parachute, since a seat that would fit a pilot wearing a parachute would be too large for a pilot not wearing one. This is why the German type was stowed in the fuselage, rather than being of the "backpack" type. Weight was – at the very beginning – also a consideration since planes had limited load capacity. Carrying a parachute impeded performance and reduced the useful offensive and fuel load.
In the U.K., Everard Calthrop, a railway engineer and breeder of Arab horses, invented and marketed through his Aerial Patents Company a "British Parachute" and the "Guardian Angel" parachute. Thomas Orde-Lees, known as the "Mad Major," demonstrated that parachutes could be used successfully from a low height (he jumped from Tower Bridge in London)which led to parachutes being used by the balloonists of the Royal Flying Corps, though they were not available for aircraft.
In 1911, Solomon Lee Van Meter, Jr. of Lexington Kentucky, submitted for and in July 1916 received a patent for a backpack style parachute – the Aviatory Life Buoy.His self-contained device featured a revolutionary quick-release mechanism – the ripcord – that allowed a falling aviator to expand the canopy only when safely away from the disabled aircraft.
Otto Heinecke, a German airship ground crewman, designed a parachute which the German air service introduced in 1918, becoming the world's first air service to introduce a standard parachute. Although many pilots were saved by these, their efficacy was relatively poor. Out of the first 70 German airmen to bail out, around a third died, 3,600 metres (11,800 ft) after being accidentally rammed by another German aircraft) and Fritz Rumey who tested it in 1918, only to have it fail at a little over 900 m (3,000 ft). These fatalities were mostly due to the chute or ripcord becoming entangled in the airframe of their spinning aircraft or because of harness failure, a problem fixed in later versions.including aces such as Oberleutnant Erich Löwenhardt (who fell from
The French, British, American and Italian air services later based their first parachute designs on the Heinecke parachute to varying extents.
In the UK Sir Frank Mears who was serving as a Major in the Royal Flying Corps in France (Kite Balloon section) registered a patent in July 1918 for a parachute with a quick release buckle, known as the "Mears parachute" which was in common use from then onwards.
The experience with parachutes during the war highlighted the need to develop a design that could be reliably used to exit a disabled airplane. For instance, tethered parachutes did not work well when the aircraft was spinning. After the war, Major Edward L. Hoffman of the United States Army led an effort to develop an improved parachute by bringing together the best elements of multiple parachute designs. Participants in the effort included Leslie Irvin and James Floyd Smith. The team eventually created the Airplane Parachute Type-A. This incorporated three key elements.
In 1919, Irvin successfully tested the parachute by jumping from an airplane. The Type-A parachute was put into production and over time saved a number of lives.The effort was recognized by the awarding of the Robert J. Collier Trophy to Major Edward L. Hoffman in 1926.
Irvin became the first person to make a premeditated free-fall parachute jump from an airplane. An early brochure of the Irvin Air Chute Company credits William O'Connor as having become, on August 24, 1920, at McCook Field near Dayton, Ohio, 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 October 20, 1922. Shortly after Harris' jump, two Dayton newspaper reporters suggested the creation of the Caterpillar Club for successful parachute jumps from disabled aircraft.
In July 4, 1924 (patent №1607) Gleb Kotelnikov of Russia became the first parachutist to apply the soft packing of a parachute instead of a hard casing.
Beginning with Italy in 1927, several countries experimented with using parachutes to drop soldiers behind enemy lines. The regular Soviet Airborne Troops were established as early as 1931 after a number of experimental military mass jumps starting from August 2, 1930. [ citation needed ]Earlier the same year, the first Soviet mass jumps led to the development of the parachuting sport in the Soviet Union. By the time of World War II, large airborne forces were trained and used in surprise attacks, as in the battles for Fort Eben-Emael and The Hague, the first large-scale, opposed landings of paratroopers in military history, by the Germans. This was followed later in the war by airborne assaults on a larger scale, such as the Battle of Crete and Operation Market Garden, the latter being the largest airborne military operation ever. Aircraft crew were routinely equipped with parachutes for emergencies as well.
In 1937, drag chutes were used in aviation for the first time, by Soviet airplanes in the Arctic that were providing support for the polar expeditions of the era, such as the first manned drifting ice station North Pole-1. The drag chute allowed airplanes to land safely on smaller ice-floes.
Today's modern parachutes are classified into two categories – ascending and descending canopies. All ascending canopies refer to paragliders, built specifically to ascend and stay aloft as long as possible. Other parachutes, including ram-air non-elliptical, are classified as descending canopies by manufacturers.
Some modern parachutes are classified as semi-rigid wings, which are maneuverable and can make a controlled descent to collapse on impact with the ground.
Round parachutes are purely a drag device (that is, unlike the ram-air types, they provide no lift) and are used in military, emergency and cargo applications. Most have large dome-shaped canopies made from a single layer of triangular cloth gores. Some skydivers call them "jellyfish 'chutes" because of the resemblance to the marine organisms. Modern sports parachutists rarely use this type. The first round parachutes were simple, flat circulars. These early parachutes suffered from instability caused by oscillations. A hole in the apex helped to vent some air and reduce the oscillations. Many military applications adopted conical, i.e., cone-shaped, or parabolic (a flat circular canopy with an extended skirt) shapes, such as the United States Army T-10 static-line parachute. A round parachute with no holes in it is more prone to oscillate and is not considered to be steerable. Some parachutes have inverted dome-shaped canopies. These are primarily used for dropping non-human payloads due to their faster rate of descent.
Forward speed (5–13 km/h) and steering can be achieved by cuts in various sections (gores) across the back, or by cutting four lines in the back thereby modifying the canopy shape to allow air to escape from the back of the canopy, providing limited forward speed. Other modifications sometimes used are cuts in various sections (gores) to cause some of the skirt to bow out. Turning is accomplished by forming the edges of the modifications, giving the parachute more speed from one side of the modification than the other. This gives the jumpers the ability to steer the parachute (such as the United States Army MC series parachutes), enabling them to avoid obstacles and to turn into the wind to minimize horizontal speed at landing.
The unique design characteristics of cruciform parachutes decrease oscillation (its user swinging back and forth) and violent turns during descent. This technology will be used by the United States Army as it replaces its older T-10 parachutes with T-11 parachutes under a program called Advanced Tactical Parachute System (ATPS). The ATPS canopy is a highly modified version of a cross/ cruciform platform and is square in appearance. The ATPS 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 the rate of descent will reduce the impact energy by almost 25% to lessen the potential for injury.
A variation on the round parachute is the pull-down apex parachute. Invented by a Frenchman named Pierre-Marcel Lemoigne,it is called a Para-Commander 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 apply load there and pull the apex closer to the load, distorting the round shape into a somewhat flattened or lenticular shape.
Some 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.
Sport parachuting has experimented with the Rogallo wing, among other shapes and forms. These were usually an attempt to increase the forward speed and reduce the landing speed offered by the other options at the time. The ram-air parachute's development and the subsequent introduction of the sail slider to slow deployment reduced the level of experimentation in the sport parachuting community. The parachutes are also hard to build.
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 and be shredded at such speeds. Ribbon parachutes have a ring-shaped canopy, often with a large hole in the centre 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 parafoils are steerable, and have two layers of fabric—top and bottom—connected by airfoil-shaped fabric ribs to form "cells". The cells fill with higher-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 . The first ram-air test jump was performed[ when? ] by United States Navy test jumper Joe Crotwell.[ citation needed ]
Personal ram-air parachutes are loosely divided into two varieties – rectangular or tapered – commonly called "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 on the leading edge (front), and sometimes in the trailing edge (tail).
Ellipticals are usually used only by sport parachutists. They 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.[ citation needed ]
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 lower glide ratio.
Wing loading of parachutes is measured similarly to that of aircraft, comparing exit weight to area of parachute fabric. Typical wing loading for students, accuracy competitors, and BASE jumpers is less than 5 kg per square meter – often 0.3 kilograms per square meter or less. Most student skydivers fly with wing loading below 5 kg per square meter. Most sport jumpers fly with wing loading between 5 and 7 kg per square meter, but many interested in performance landings exceed this wing loading. Professional Canopy pilots compete with wing loading of 10 to over 15 kilograms per square meter. While ram-air parachutes with wing loading higher than 20 kilograms per square meter 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.[ citation needed ]
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 1.5-metre (4.9 ft) tall entry gate. Current world records exceed 180 metres (590 ft).
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 a small tolerance, or "sweet spot", for timing the landing flare.
Because of their predictable opening characteristics, parachutes with a medium aspect ratio around 2.1 are widely used for reserves, BASE, and canopy formation competition. Most medium aspect ratio parachutes have seven cells.
High aspect ratio parachutes have the flattest glide and the largest tolerance 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.
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. Four collections of lines go through the grommets to the risers (risers are strips of webbing joining the harness and the rigging lines of a parachute). 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. Reducing the amount of fabric decreases the air resistance. This can be done by making the slider smaller, inserting a mesh panel, or cutting a hole in the slider.
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. 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 sometimes not recovered after 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.
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 a malfunction where the main parachute fails to deploy correctly or fully. In the United States 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.
Exact numbers are difficult to estimate because parachute design, maintenance, loading, packing technique and operator experience has a significant impact on malfunction rates. Approximately one in a thousand sport main parachute openings malfunctions, requiring the use of the reserve parachute, although some skydivers have many thousands of jumps and never needed to use their reserve parachute.
Reserve parachutes are packed and deployed somewhat differently. They are also designed more conservatively, favouring reliability over responsiveness and are built and tested to more exacting standards, making them more reliable than main parachutes. Regulated inspection intervals, coupled with significantly less use contributes to reliability as wear on some components can adversely affect reliability. The primary safety advantage of a reserve parachute 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 there is also a small possibility that a malfunctioning main parachute cannot be released and thus interfere with the reserve parachute. In the United States, the 2017 average fatality rate is recorded to be 1 in 133,571 jumps.
Injuries and fatalities in sport skydiving are possible even under a fully functional main parachute, such as may occur if the skydiver makes an error in judgment while flying the canopy which results in a high-speed impact either with the ground or with a hazard on the ground, which might otherwise have been avoided, or results in collision with another skydiver under canopy.
Below are listed the malfunctions specific to round parachutes.
On August 16, 1960, Joseph Kittinger, in the Excelsior III test jump, set the previous world record for the highest parachute jump. He jumped from a balloon at an altitude of 102,800 feet (31,333 m) (which was also a manned balloon altitude record at the time). A small stabilizer chute deployed successfully, and Kittinger fell for 4 minutes and 36 seconds, also setting a still-standing world record for the longest parachute free-fall, if falling with a stabilizer chute is counted as free-fall. At an altitude of 17,500 feet (5,300 m), Kittinger opened his main chute and landed safely in the New Mexico desert. The whole descent took 13 minutes and 45 seconds. During the descent, Kittinger experienced temperatures as low as −94 °F (−70 °C). In the free-fall stage, he reached a top speed of 614 mph (988 km/h or 274 m/s), or Mach 0.8.
According to Guinness World Records , Yevgeni Nikolayevich Andreyev (Soviet Union) held the official FAI record for the longest free-fall parachute jump (without drogue chute) after falling for 24,500 m (80,380 ft) from an altitude of 25,457 m (83,523 ft) near the city of Saratov, Russia on November 1, 1962, until broken by Felix Baumgartner in 2012.
Felix Baumgartner broke Joseph Kittinger's record on October 14, 2012, with a jump from an altitude of 127,852 feet (38,969.3 m) and reaching speeds up to 833.9 mph (1,342.0 km/h or 372.8 m/s), or nearly Mach 1.1. Kittinger was an advisor for Baumgartner's jump.
Alan Eustace made a jump from the stratosphere on October 24, 2014, from an altitude of 135,889.108 feet (41,419 m). However, because Eustace's jump involved a drogue parachute while Baumgartner's did not, their vertical speed and free fall distance records remain in different record categories.
BASE jumping, also sometimes written as B.A.S.E. jumping, is parachuting or wingsuit flying from a fixed structure or cliff. "BASE" is an acronym that stands for four categories of fixed objects from which one can jump: building, antenna, span, and earth (cliff). Due to the lower altitudes of the jumps, BASE jumping is significantly more dangerous than skydiving from a plane. In the U.S., BASE jumping is currently regarded by many as a fringe extreme sport or stunt.
In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it.
Wingsuit flying is the sport of flying through the air using a wingsuit which adds surface area to the human body to enable a significant increase in lift. The modern wingsuit, first developed in the late 1990s, creates a surface area with fabric between the legs and under the arms. Wingsuits are sometimes referred to as "birdman suits", "squirrel suits", and "bat suits".
A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, to provide control and stability, or as a pilot parachute to deploy a larger parachute. It was invented in Russia by Gleb Kotelnikov in 1912.
Bill Booth is an American engineer, inventor, and entrepreneur in the skydiving equipment manufacturing industry. His invention of the 3-ring release safety device has enhanced skydiving safety.
Automatic activation device (AAD) in skydiving terminology refers to an electronic-pyrotechnic or mechanical device that automatically opens the main or reserve parachute container at a preset altitude or after a preset time.
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. A ram-air parachute has a tendency to open very rapidly. At high velocities, the opening shock from such a rapid deployment can cause damage to the canopy or injury to the jumper. The slider was developed as a way of mitigating this. During deployment, the slider slides down from the canopy to just above the risers. It is slowed by air resistance as it descends and reduces the rate at which the lines can spread and therefore the speed at which the canopy can open and inflate. The slider also deflects some of the rising air column away from the center of the canopy as it inflates. This also helps moderate the speed of opening. This invention solved the rapid deployment problem with ram-air designs. Sliders also reduce the chance of the lines twisting to cause a malfunction.
A malfunction is a partial or total failure of a parachuting device to operate as intended. Malfunctions may require a skydiver to cut away his or her main parachute and deploy the reserve parachute.
A static line is a fixed cord attached to a large, stable object. It is used to open parachutes automatically for paratroopers and novice parachutists.
A pilot chute is a small auxiliary parachute used to deploy the main or reserve parachute. The pilot chute is connected to the deployment bag containing the parachute by a bridle. On modern skydiving rigs three types of pilot chutes can be found:
Tandem skydiving or tandem parachuting refers to a type of skydiving where a student skydiver is connected to a harness attached to a tandem instructor. The instructor guides the student through the whole jump from exit through freefall, piloting the canopy, and landing. The student needs only minimal instruction before making a tandem jump with the instructor. In the United States most skydiving centers and clubs require that you be 18 years or older to skydive whereas in other countries the minimum age can be lower or higher. This is one of three commonly used training methods for beginning skydivers; the others being static line and Accelerated Freefall.
The Skyhook is United Parachute Technologies version of a Main-Assisted Reserve Deployment system (MARD), a safety feature on skydiving parachute systems. It builds on the concept underlying an ordinary reserve static line (RSL), which uses the force of the departing main parachute to open the reserve parachute compartment after the malfunctioning main parachute is cut-away, by further using the force of the departing main parachute to extract the reserve parachute out of the reserve compartment. This greatly decreases the time, and hence loss of altitude, required to fully open the reserve parachute.
Cut-away is a skydiving term referring to disconnecting the main parachute from the harness-container in case of a malfunction in preparation for opening the reserve parachute. The 3-ring release system on parachutes allows a rapid cut-away in the event of an emergency.
Accelerated freefall (AFF) is a method of skydiving training. This method of skydiving training is called "accelerated" because the progression is the fastest way to experience solo freefall, normally from 10,000 to 15,000 feet "Above Ground Level" (AGL). In static line progression, more jumps are required to experience freefall, but the jumps are less expensive for the student as one instructor can dispatch multiple students per load and students are initially dispatched from lower altitudes. Under accelerated freefall, one or sometimes two instructors are dedicated just to one student.
Leslie Leroy Irvin made the first premeditated free-fall parachute jump in 1919. Irvin was born in Los Angeles. He became a stunt-man for the fledgling Californian film industry, for which he had to perform acrobatics on trapezes from balloons and then make descents using a parachute. Irvin made his first jump when aged fourteen. For a film called Sky High, he first jumped from an aircraft from 1,000 feet in 1914. He developed his own static line parachute as a life-saving device in 1918 and jumped with it several times.
Georgia Ann Thompson Broadwick, or Georgia Broadwick, was an American pioneering parachutist. She was nicknamed 'Tiny', as she weighed only 85 pounds (39 kg) and was 5 feet (1.5 m) tall. She invented the ripcord.
Parachuting is a method of transiting from a high point to Earth with the aid of gravity, involving the control of speed during the descent with the use of a parachute or parachutes. It may involve more or less free-falling which is a period when the parachute has not yet been deployed and the body gradually accelerates to terminal velocity.
The T-10 Parachute is a series of static line-deployed parachutes used by the United States armed forces for combat mass-assault airborne operations and training. The T-10 parachute was introduced in the early 1950s. In 1976, the B model introduced the anti-inversion net; in 1986, the C model was introduced, which changed the pocket band free length from 4" to 7½". The T-10D, adopted in 2000, includes the detachable pack tray, which in itself includes the 15' universal static line and 5' extension static line. The T-10D is currently being replaced by the T-11 parachute system. In 2006, all T-10C parachutes were revised by adding one static line stow bar to each side of the pack tray; the material for the T-10C was also changed to the Army's Foliage Green #504.
CharlesBroadwick was an American pioneering parachutist and inventor. Speaking about Broadwick, an executive director of the U.S. Parachute Association, Ed Scott, said "just about all modern parachute systems" use ideas Broadwick developed: "an integrated, form-fitting harness and container system nestled on the back." Broadwick also developed the static line for deploying a parachute where a line attached to an aircraft pulls the parachute from its pouch. Static lines are still used today, for instance by paratroopers and novice skydivers. U.S. Army Warrant Officer Jeremiah Jones commented, "[Broadwick] is like the grandfather of paratroopers." In addition, Broadwick demonstrated parachute jumps at fairs and taught and equipped famous female parachutist Tiny Broadwick.
Luke Aikins is an American professional skydiver, BASE jumper, pilot, and aerial photographer. He is the first person to intentionally dive from mid-tropospheric altitude and land safely without a parachute or a wingsuit and the second skydiver to intentionally and safely land without using a parachute.
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