parachute

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(păr'ə-shūt') pronunciation
n.
  1. An apparatus used to retard free fall from an aircraft, consisting of a light, usually hemispherical canopy attached by cords to a harness and worn or stored folded until deployed in descent.
  2. Any of various similar unpowered devices that are used for retarding free-speeding or free-falling motion.

v., -chut·ed, -chut·ing, -chutes.

v.tr.
To drop (supplies or troops, for example) by means of a parachute.

v.intr.
To descend by means of a parachute.

[French : para(sol), parasol; see parasol + chute, fall; see chute.]

parachutic par'a·chut'ic adj.
parachutist par'a·chut'ist or par'a·chut'er n.


Umbrella-like device for slowing the descent of a body falling through the atmosphere. Separate panels sewn together form a canopy attached by suspension lines to a harness worn by the user. Originally designed to provide a safe escape from a disabled aircraft, parachutes are also used for dropping supplies and for slowing returning space capsules. The parachute was conceived by the 14th century, but practical demonstrations began only in the 1780s in France, leading in 1797 to a 3,200-ft (1,000-m) exhibition jump from a balloon by Andr-Jacques Garnerin (17691823); in 1802 he made a jump of 8,000 ft (2,400 m). Early parachute material was canvas, which was later replaced by silk and then nylon. skydiving.

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Background

A parachute is a device used to slow the movement of a person or object as it falls or moves through the air. Used primarily for safe descent from high altitudes (e.g., a spacecraft reentering the atmosphere, a person or object dropped from an airplane), parachutes can also be used in horizontal configurations to slow objects like race cars that have finished their runs.

There are two basic types of parachutes. One is a dome canopy made of fabric in a shape that ranges from a hemisphere to a cone; the canopy traps air inside its envelope, creating a region of high pressure that retards movement in the direction opposite the entering air flow. The other is a rectangular parafoil, or ram-air canopy, consisting of a series of tubular cells; commonly used by sport jumpers, the parafoil acts as a wing, allowing the jumper to "fly" toward a target. Either type of parachute weighs less than 15 lb (7 kg) and costs from $1,200-$ 1,500.

In addition to the fabric canopy, a parachute designed to be used by a person must be equipped with a harness that is worn by the user. Attached to the harness is a container that holds the canopy; often this is a back-pack, but it can also extend low enough for the user to sit on it. There is an actuation device that opens the container and releases the canopy for use; one of the most common actuation devices is a ripcord. When the container is opened, a small pilot chute about 3 ft (1 m) in diameter is pulled out, either by a spring mechanism or by hand. This pilot chute, in turn, pulls the main canopy from the container. Some type of deployment device, such as a fabric sleeve, is used to slow the opening of the canopy so that the suspension lines will have time to straighten. A gradual opening of the canopy also reduces the shock to the equipment and the user that a more sudden opening would cause.

History

There is some evidence that rigid, umbrella-like parachutes were used for entertainment in China as early as the twelfth century, allowing people to jump from high places and float to the ground. The first recorded design for a parachute was drawn by Leonardo da Vinci in 1495. It consisted of a pyramid-shaped, linen canopy held open by a square, wooden frame. It was proposed as an escape device to allow people to jump from a burning building, but there is no evidence that it was ever tested.

Parachute development really began in the eighteenth century. In 1783 Louis-Sebastien Lenormand, a French physicist, jumped from a tree while holding two parasols. Two years later, J. P. Blanchard, another Frenchman, used silk to make the first parachute that was not held open by a rigid frame. There is some evidence that he used the device to jump from a hot air balloon.

There is extensive evidence that Andre Jacques Garnerin made numerous parachute jumps from hot air balloons, beginning in 1797. His first jump, in Paris, was from an altitude of at least 2,000 ft (600 m). In 1802, he jumped from an altitude of 8,000 ft (2,400 m); he rode in a basket attached to a wooden pole that extended downward from the apex (top) of the canopy, which was made of either silk or canvas. The parachute assembly weighed about 100 lb (45 kg). During the descent, the canopy oscillated so wildly that Garnerin became airsick. In fact, he was once quoted as saying that he "usually experienced [painful vomiting] for several hours after a descent in a parachute." In 1804, French scientist Joseph Lelandes introduced the apex vent—a circular hole in the center of the canopy—and thus eliminated the troublesome oscillations.

Americans became involved in parachute development in 1901 when Charles Broadwick designed a parachute pack that was laced together with a cord. When the parachutist jumped, a line connecting the cord with the aircraft caused the cord to break, opening the pack and pulling out the parachute. In 1912, Captain Albert Berry of the U.S. Army accomplished the first parachute jump from a moving airplane. Parachutes did not become standard equipment for American military pilots until after World War I (German pilots used them during the final year of that war).

Parachutes were widely used during World War II, not only as life-saving devices for pilots, but also for troop deployment. In 1944, an American named Frank Derry patented a design that placed slots in the outer edge of the canopy to make a parachute steerable.

The world record for the highest parachute jump was set in 1960. Joe Kittinger, a test pilot for the U.S. Air Force's Project Excelsior ascended in a balloon to an altitude of 102,800 ft (31 km) and jumped. Using only a 6ft (1.8 m) parachute to keep him in a stable, vertical position, he experienced essentially free fall for four minutes and 38 seconds, reaching a speed of 714 mph (1,150 km/h). At an altitude of 17,500 ft (5.3 km), his 28-ft (8.5-m) parachute opened. In all, his fall lasted nearly 14 minutes.

Raw Materials

Parachute canopies were first made of canvas. Silk proved to be more practical because it was thin, lightweight, strong, easy to pack, fire resistant, and springy. During World War II, the United States was unable to import silk from Japan, and parachute manufacturers began using nylon fabric. The material turned out to be superior to silk because it was more elastic, more resistant to mildew, and less expensive. Other fabrics, such as Dacron and Kevlar, have recently been used for parachute canopies, but nylon remains the most popular material. More specifically, parachutes are made of "ripstop" nylon that is woven with a double or extra-thick thread at regular intervals, creating a pattern of small squares. This structure keeps small tears from spreading.

Other fabric components such as reinforcing tape, harness straps, and suspension lines are also made of nylon. Metal connectors are made of forged steel that is plated with cadmium to prevent rusting. Ripcords are made from stainless steel cable.

One parachute manufacturing plant lists its monthly materials use as exceeding 400,000 sq yd (330,000 m2) of fabric, 500,000 yd (455 km) of tape and webbing, 2.3 million yd (2,000 km) of cord, and 3,000 lb (1,400 kg) of thread.

Design

A dome canopy may consist of a flat circle of fabric, or it may have a conical or parabolic shape that will not lie flat when spread out. It has a vent hole at the apex to allow some air to flow through the open canopy. Some designs also have a few mesh panels near the outer edge of the canopy to aid in steering the descent. Some designs use continuous suspension lines that run across the entire span of the canopy and extend to the harness on each end. Others—as described in "The Manufacturing Process"—use segments of suspension lines that are attached only to the outer edge of the canopy (and across the apex vent).

The Manufacturing
Process

Assembling

  • Ripstop nylon cloth is spread on a long table and cut according to pattern pieces. The cutting may be done by a computer-guided mechanism or by a person using a round-bladed electric knife.
  • Four trapezoidal panels are sewn together to form a wedge-shaped "gore" about 13 ft (3.96 m) long. A two-needle industrial sewing machine stitches two parallel rows, maintaining consistent separation between the rows. To provide sufficient strength and enclose the raw fabric edges, a "French fell" seam is used; an attachment on the sewing machine folds the cloth edges as a highly skilled operator feeds the material through it. Depending on the parachute's specific design, a few of the gore sections may be sewn using mesh rather than ripstop nylon fabric for the largest panel.
  • A number of gores (typically 24) are sewn together, side by side, to form a circular canopy. The seams are sewn in the same manner as in Step 2.
  • Every panel and every seam is carefully inspected on a lighted inspection table to make certain that the seams are correctly folded and sewn and that there are no flaws in the cloth. If any weaving defects, sewn-in pleats, or an incorrect number of stitches per inch is found, the canopy is rejected. The problems are recorded on an inspection sheet, and they must be repaired before additional work is done.

Finishing

  • A tape the same width as the original seam is sewn on top of each radial seam using two more rows of stitching. This tape strengthens the canopy.
  • The top of each gore is a few inches (several centimeters) wide; after the gores are sewn together, their tops form a small open circle (the vent) at the center of the canopy. To reinforce the vent and to keep the cloth from fraying, the fabric is rolled around a piece of webbing and sewn with a four-needle sewing machine, which stitches four parallel rows at once.
  • The bottom of each gore is 2-3 ft (0.5-1 m) wide. Sewn together, these edges form the outer edge (the skirt) of the canopy. This edge is finished in the same manner as the vent, as in Step 6.
  • A short piece of reinforcing tape is sewn to the skirt at each radial tape. It is folded into a "V" pointing outward from the canopy. A specialized automatic sewing machine, designed for this specific operation, is used to sew precisely the same number of stitches in exactly the same pattern every time.
  • One end of a 20 ft (6 m) long suspension line is threaded through each V-shaped tab, which will distribute the load from the line to a section of the skirt hem. Using a special zigzag pattern that is both strong and elastic, the suspension cord is sewn to the canopy's hem tape and to the canopy seam for a length of 4-10 in (10-25 cm).
  • After the 24 suspension lines are sewn to the canopy, 12 1 ft (30 cm) long apex lines are similarly sewn to the central vent. One end of each line is stitched into a V-tab, then the line crosses the vent to the opposite seam where the other end is stitched into a V-tab.

Rigging

  • The canopy is attached to the harness by tying the suspension lines to steel connector links on the harness. The lines must not be twisted or tangled if the parachute is to function properly. Attaching the lines to their correct sequential positions on the connecting links of the harness and making certain that the lines are straight is called rigging the parachute. The line end may be knotted at the harness link, or the end may be threaded back inside the line like a "Chinese fingertrap."
  • To keep the attaching knot or fingertrap from untying, the end of each suspension line is zigzag stitched to the main section of the line.
  • Every assembly operation, every seam, even every stitch is reviewed for completion and correctness. When the parachute is approved, it is marked with a serial number, the date of manufacture, and a final inspection stamp.
  • A parachute rigger licensed by the Federal Aviation Administration (FAA) assembles the component parts (e.g., canopy, suspension lines, pilot chute) and carefully folds and arranges them in the pack, securing it with the appropriate activation device such as a ripcord.

Quality Control

The quality control systems used by parachute manufacturers must meet the requirements for civil and/or military aviation equipment established by the federal government, under the supervision of the FAA. In addition to the lighted inspection tables mentioned, other types of testing equipment include tensile test machines (to measure strength of fabric and seams while being pulled), permeameters (to test the amount of air that can pass through the fabric), and basic measuring devices (e.g., to count stitches per inch).

The Future

Like other manufacturers, parachute makers continually search for better materials and designs. Perhaps the most intriguing future development for parachutes, however, is their potential use to control the emergency descent of entire aircraft. At least one company, Ballistic Recovery Systems Inc. (BRS), is already manufacturing such General Aviation Recovery Devices (GARDs) for use on small airplanes.

Using an extremely low-porosity, strong, lightweight fabric for the canopy, the manufacturer bakes a 1,600-square-foot (150-m2) canopy and vacuum-packs it into a 15×10×6-in (38×25×15-cm) bag weighing 25 lb (10 kg). The pack is installed inside the roof liner of the airplane near its center of gravity. To ensure that the parachute will deploy even in low-altitude emergencies, it is activated by a small rocket device.

By the late 1990s, more than 14,000 light and ultralight airplanes have already been equipped with GARDs costing $2,000-$4,000 each. As of June 1998, BRS had documented 121 lives saved by the devices. The FAA has approved a GARD system for two models of Cessna airplanes.

A system of five parafoils has been proposed for use on Boeing 747 commercial airliners. The complex system would allow the pilot to control the deployment of each canopy. Rather than dropping the airplane straight down, the system would establish a glide path that would allow the pilot to control and land the craft. The practicality of the proposed system has not yet been proven.

Where to Learn More

Books

Bates, Jim. Parachuting: From Student to Skydiver. Blue Ridge Summit, PA: TAB Books, 1990.

Poynter, Dan. Parachuting: The Skydiver's Handbook. Santa Barbara, CA: Para Publishing, 1989.

Other

"Ballistic Recovery Systems." http://users.aol.com/BRSchute/BRS.HTML (February 1999).

"Strong Enterprises Company Overview." http://www.strongparachutes.com (February 1999).

[Article by: Loretta Hall]


A flexible, lightweight structure, generally intended to retard the passage of an object within or through atmosphere by materially increasing the resistive surface. A parachute is a decelerator or air-braking device in the general form of an oblate hemisphere. The parachute is the only suitably demonstrated device for emergency descent from aircraft. It comprises a canopy and cords, which form the suspension and attachment between canopy and object. A parachute canopy is a membrane which relies upon pressure differential across it to maintain its inflated shape. The differential is created by entrapment of an air mass on the inside and movement of the air on the outside.


n.a cloth canopy which fills with air and allows a person or heavy object attached to it to descend slowly when dropped from an aircraft, or which is released from the rear of an aircraft on landing to act as a brake.

v.

drop or cause to drop from an aircraft by parachute: airborne units parachuted in to secure the airport.

Etymology: late 18th century: from French para- 'protection against' + chute 'fall.'

See the Introduction, Abbreviations and Pronunciation for further details.

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Floating in a Parachute  
Floating in a Parachute
Who packed your parachute? André-Jacques Garnerin would have probably known the answer to that question. Garnerin was one of the early inventors of the parachute who, on this date in 1797, made the first successful silk parachute jump. He jumped out of a hot-air balloon from more than 3,000 ft. (915 m.) over Parc Monceau in Paris. Garnerin also developed the vented parachute, which improved the stability and smoothness of the fall.

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From our Archives: Today's Highlights, October 22, 2007

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parachute, umbrellalike device designed to retard the descent of a falling body by creating drag as it passes through the air. The development of modern aircraft has led to many experiments in the aerodynamic problems of parachute design, with the result that the parachute of today is a highly efficient instrument. It must permit slow descent, must be highly stable, have little weight and a small area, and must retain its shape and maintain its balance in descent. Originally made of silk, parachutes are usually constructed from nylon or Kevlar. The traditional parachute takes the form of an umbrella, from which a series of cords converge downward to a harness strapped to the user; modern parachutes are wing-shaped, allowing precise control by the parachutist. By pulling on the appropriate control cords, the parachutist can spill air out of one side or another, and increase or decrease the lift of the wing, thus turning, diving, or even hovering under favorable conditions. Parachuting has its dangers. Folding a parachute requires a high degree of skill, and an improperly folded chute will not open. Before the parachute can be opened, the user must be clear of the aircraft in order to avoid entanglement, or fouling. Finally, the harness must be easily detachable, or else the parachutist might be drowned or dragged along the ground. The rate of descent for a traditional parachute is about 18 ft (5.5 m) per sec; sport parachutists manage to reduce that speed significantly.

A French aeronaut, Jean Pierre Blanchard, claimed the invention of the parachute in 1785, and the first successful parachute descent from a great height was made in 1797 by the French aeronaut Jacques Garnerin, who dropped 3,000 ft (920 m) from a balloon. Parachutes began as an escape system for persons aboard balloons or aircraft unable to land safely. Modern military jet aircraft are provided with ejection seats that shoot occupants free of their craft and automatically release a parachute when they are at a safe altitude. In addition, since World War II parachutes have been used by the military for airborne operations and emergency resupply. Skydiving and the more dangerous swooping (canopy piloting) are forms of sport parachuting. Parachutes are also used as braking devices for rockets, space vehicles, airplanes, and high-speed surface vehicles.

Bibliography

See study by B. Sellick (1981).


Word Tutor:

parachute

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pronunciation

IN BRIEF: A large cloth device that opens up like an umbrella and is used for slowing down a person or thing dropping from an airplane.

pronunciation The parachute was packed along with the pilot's emergency supplies.

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sign description: One open 5-hand moves downward above the index finger.




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Parachutes obviously represent a means of escape from a dangerous situation. In a dream, a parachute could refer to our coping mechanisms, or it could refer to bailing out of a difficult predicament. Alternatively, some people sky dive for fun, so parachuting in a dream could refer to thrill-seeking or a sense of total freedom. Also note the idiom "golden parachute."


An umbrella-shaped area of fabric for producing drag. The fabric body is the canopy, constructed of a number of tapering strips, called gores, which meet at the top like slices of an orange. A hole at the top, called a vent, allows air to flow through, thereby helping to keep the parachute steady. Fastened firmly between the gores are strong cords, called shrouds, which distribute the load evenly over the canopy. Ribbon parachutes have a canopy built of strips joined only at the top. This design retards the aircraft’s speed on landing. Round parachutes are designed to produce drag and stabilize loads dropped from an aircraft. The round parachute also is used in older aircraft with extremely high landing speeds to help slow the aircraft. Square parachutes, used for skydiving, are constructed of fabric and designed to behave like an airfoil. They are extremely maneuverable. The three main types of parachute packs are the seat pack, back pack, and observer. The observer parachute clips onto the lungs of the harness and is positioned on the wearer’s chest. Emergency parachutes are also normally positioned on the wearer’s chest. Parachutes used to retard the aircraft’s speed on landing are known as tail parachutes, tail chutes, or drag chutes. The parachutes may be used by crews or troops and for dropping supplies, providing anti-spinning properties, and slowing down aircraft or even bombs.

Picture 1 of parachute



Tail/drogue parachute


Tail/drogue parachute


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For a list of words related to parachute, see:
  • Aviation and Aerodynamics - parachute: umbrellalike cloth contrivance used to retard falling speed of person or object dropped from aircraft


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Parachutes opening

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 cloth, originally silk, now most commonly nylon. Parachutes must slow an object's terminal vertical speed by a minimum 75% in order to be classified as such. Depending on the situation, parachutes are used with a variety of loads, including people, food, equipment, space capsules, and bombs.

Drogue chutes are used to aid horizontal deceleration of a vehicle (a fixed-wing aircraft, or a drag racer), or to provide stability (tandem free-fall, or space shuttle after a touchdown).

The word "parachute" comes from the French prefix paracete, originally from the Greek, meaning to protect against, and chute, the French word for "fall", and it was originally coined, as a hybrid word which meant literally "that which protects against a fall", by the French aeronaut François Blanchard (1753–1809) in 1785.

Contents

History

Early Renaissance Forms

The oldest known depiction of a parachute, by an anonymous author (Italy, 1470s)
Veranzio's 1595 parachute design titled "Flying Man"

The earliest evidence for the parachute dates back to the Renaissance period.[1] The oldest parachute design appears in an anonymous manuscript from 1470s Renaissance Italy (British Museum Add. MSS 34,113, fol. 200v), showing a free-hanging man clutching a cross bar frame attached to a conical canopy.[2] As a safety measure, four straps run from the ends of the rods to a waist belt. The design is a marked improvement over another folio (189v) which depicts a man trying to break the force of his fall by the means of two long cloth streamers fastened to two bars which he grips with his hands.[3] Although the surface area of the parachute design appears to be too small to offer effective resistance to the friction of the air and the wooden base-frame is superfluous and potentially harming, the revolutionary character of the new concept is obvious.[3]

Only slightly later, a more sophisticated parachute was sketched by the polymath Leonardo da Vinci in his Codex Atlanticus (fol. 381v) dated to ca. 1485.[2] 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.[3] It is not known whether the Italian inventor was influenced by the earlier design, but he may have learnt about the idea through the intensive oral communication among artist-engineers of the time.[4] The feasibility of Leonardo's pyramidal design was successfully tested in 2000 by the British Adrian Nicholas and again in 2008 by another skydiver.[5] 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".[1]

The Venetian inventor Fausto Veranzio (1551–1617) examined da Vinci's parachute sketch, and set out to implement one of his own. He kept the square frame, but replaced the canopy with a bulging sail-like piece of cloth which he came to realize decelerates the fall more effectively.[3] A now-famous depiction of a parachute that he dubbed Homo Volans (Flying Man) appeared in his book on mechanics, Machinae Novae (1615 or 1616), alongside a number of other devices and technical concepts. It is widely believed that in 1617, Veranzio implemented his design and tested the parachute by jumping from St Mark's Campanile in Venice and that 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, in this book, John Wilkins wrote about flying, not about parachutes. He neither mentions Fausto Veranzio nor a parachute jump nor any event in 1617. Furthermore, the story does not explain how Veranzio could have managed to get the wooden frame out of the tower and into a horizontal position with himself underneath without the device tilting and collapsing. No evidence has been found that anyone ever tested Veranzio's parachute.[6]

Modern parachutes

Louis-Sébastien Lenormand jumps from the tower of the Montpellier observatory, 1783. Illustration from the late 19th century
First use of a frameless parachute, by André Garnerin in 1797
Schematic depiction of Garnerin's parachute, from an early nineteenth century illustration
Picture published in a Dutch newspaper "De Prins der Geïllustreerde Bladen" (Feb 18, 1911)[7]
Gleb Kotelnikov and his invention, the knapsack parachute

18th and 19th centuries

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 the prefix para-, for "defense against," and chute, the French word for "fall," to describe the device's function, the word literally meaning "that which protects against a fall."

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 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.

Eve of World War One

In 1911 a successful test was done 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.[7] The following year Franz Reichelt fell to his death from the tower demonstrating his wearable parachute.

Also in 1911, Grant Morton made the first parachute jump from an airplane, 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 where he held the chute in his arms as he left the aircraft. In the same year, a Russian inventor Gleb Kotelnikov invented the first knapsack parachute,[8] 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 parachute by accelerating a Russo-Balt automobile to the top speed, and then opening a parachute attached to the back seat, thus inventing also the drogue parachute.[8]

On 1 March 1912, US Army Captain Albert Leo Stevens 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, Mo. The jump utilized a 'pack' style chute with the 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.[9] On 21 June 1913, Georgia Broadwick became the first woman to parachute jump from a moving aircraft, doing so over Los Angeles.[10]

World War One

The first military use for the parachute was for use by artillery detectors 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 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. The main part of the parachute was in a bag suspended from the balloon with the pilot wearing only a simple waist harness which was 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 by the Germans for their observation balloon crews, and then later by the British and French for their observation balloon crews. 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,[11] 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.[12]

In the UK, Everard Calthrop, a railway engineer, and breeder of Arab horses, invented and marketed through his Aerial Patents Company a "British 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 their being used by the Royal Flying Corps.

In 1911, Solomon Lee Van Meter, Jr. of Lexington Kentucky, submitted for and in 1916 received a patent for a backpack style parachute - the Aviatory Life Buoy, Patent # 1192479, July 25, 1916.[13] 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.[14]

The German air service, in 1918, became the world's first to introduce a standard parachute and the only one at the time. Despite Germany issuing their pilots with parachutes, their efficiency was relatively poor. As a result, many pilots died whilst using them, including aces such as Oberleutnant Erich Lowenhardt (who fell from 12,000 feet (3,700 m) after being accidentally rammed by another German aircraft) and Fritz Rumey who tested it in 1918, only to have it fail at a little over 3,000 ft (910 m).

Post World War One

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 free-fall parachute jump from an airplane.[15]

An early brochure of the Irvin Air Chute Company credits William O'Connor as having become, on 24 August 1920 at McCook Field near Dayton, Ohio, the first person to be saved by an Irvin parachute.[16] Another life-saving jump was made at McCook Field by test pilot Lt. Harold H. Harris on 20 October 1922. Shortly after Harris' jump, two Dayton newspaper reporters suggested the creation of the Caterpillar Club for successful parachute jumps from disabled aircraft.

In 1924 Gleb Kotelnikov became the first parachutist to apply the soft packing of a parachute instead of a hard casing.[17]

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 the August 2, 1930.[8] Earlier the same year, in 1930, the first Soviet mass jumps led to the development of the parachuting sport in the Soviet Union.[8] By the time of World War II, large airborne forces were trained and used in surprise attacks, as in the Battle for The Hague, the first large scale deployment of airborne troops in military history, by the Germans (whose operation failed totally)[18] and in 1941 Battle of Crete and in 1944 the Operation Market Garden, again in Holland and again a complete failure but still the largest airborne military operation ever carried out.[19] Aircraft crew were routinely equipped with parachutes for emergencies as well.[citation needed]

In 1937, drag chutes were used in aviation for the first time, by the Soviet airplanes in the Arctic that were providing support for the famous polar expeditions of the era, such as the first manned drifting ice station North Pole-1. The drag chute allowed to land safely on the ice-floes of smaller size.[8]

Types of parachutes

Today's modern parachutes are classified into two categories: ascending and descending canopies. All ascending canopies refer to Paragliders which are 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 break on impact with the ground.

Round types

An American paratrooper using an MC1-1C series 'round' parachute

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. These have large dome-shaped canopies made from a single layer of triangular cloth gores. Some skydivers call them "jellyfish 'chutes" because of the resemblance. Modern sports parachutists rarely use this type.

The 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 US 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.

A large (3-8 mph) forward speed and steering can be achieved by cuts in various sections (gores) across the back, or by cutting 4 lines in the back thereby modifying the canopy to allow air to escape from the back of the canopy, providing limited forward speed. Modifications can skirt bow out.[clarification needed] 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, enabling them to avoid obstacles and to turn into the wind to minimize horizontal speed at jumping.

Cruciform (square) types

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

Boeing B-47B-40BW of the 306th Bomb Wing (Medium) at MacDill AFB, Florida, landing with drag chute
RAF Typhoon using a parachute for braking after landing
animation showing a parachute release system

Annular and pull-down apex types

A variation on the round parachute is the pull down apex parachute. Invented by a Frenchman named Pierre-Marcel Lemoigne[20][21][22][citation needed], it is referred to as 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 applies load there and pulls 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.

Rogallo wing and other types

Sport parachuting has experimented with the Rogallo wing, among other shapes and forms. These were nearly always 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 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 types

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

Personal parachutes

Deployment

Reserve parachutes usually have a ripcord deployment system, which was first designed by Theodore Moscicki, but most modern main parachutes used by sports parachutists use a form of hand-deployed pilot chute. 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.

Varieties of personal ram-airs

A U.S. Navy Parachute Team "Leap Frogs" jumper landing a 'square' ram-air parachute

Personal ram-air parachutes are loosely divided into two varieties: rectangular or tapered, commonly referred to as "squares" or "ellipticals" respectively. Medium-performance canopies (reserve-, BASE-, canopy formation-, and accuracy-type) are usually rectangular. 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 3+ 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 5-foot (1.5 m) tall entry gate. Current world records exceed 600 feet (180 m).

Aspect ratio is another way to measure ram-air parachutes. Aspect ratios of parachutes are measured the same way as aircraft wings, by comparing span with chord. Low aspect ratio parachutes (i.e. span 1.8 times the chord) are now limited to precision landing competitions. Popular precision landing parachutes include Jalbert (now NAA) Para-Foils and John Eiff's series of Challenger Classics. While low aspect ratio parachutes tend to be extremely stable—with gentle stall characteristics—they suffer from steep glide ratios and small "sweet spots" for timing the landing flare.

Medium aspect ratio (i.e. 2.1) parachutes are widely used for reserves, BASE, and canopy formation competition because of their predictable opening characteristics. Most medium aspect ratio parachutes have seven cells.

High aspect ratio parachutes have the flattest glide and the largest "sweet spots" (for timing the landing flare) but the least predictable openings. An aspect ratio of 2.7 is about the upper limit for parachutes. High aspect ratio canopies typically have nine or more cells. All reserve ram-air parachutes are of the square variety, because of the greater reliability, and the less-demanding handling characteristics.

General characteristics of ram-airs

Main parachutes used by skydivers today are designed to open softly. Overly rapid deployment was an early problem with ram-air designs. The primary innovation that slows the deployment of a ram-air canopy is the slider; a small rectangular piece of fabric with a grommet near each corner. 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.

Safety

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

Parachute malfunctions

The Apollo 15 spacecraft landed safely despite a parachute failure.

Below are listed malfunctions specific to round-parachutes. For malfunctions specific to square parachutes, see Malfunction (parachuting).

  • A "Mae West" or "Blown Periphery" is a type of round parachute malfunction which contorts the shape of the canopy into the appearance of a brassiere, presumably one outward, is blown against the opposite skirt. The column of nylon fabric, buffeted by the wind, rapidly heats from friction and fuses together, removing any chance 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.
  • A "Barber's pole" describes having a mess of lines tangled “behind your head and you have to cut away your main chute and pull your reserve.”[23]
  • The "Horseshoe" Is an out of sequence deployment. This is when the parachute lines and bag are released before the bag drogue and bridle. This can cause the lines to become tangled or a situation where the parachute drogue not release from the container.[23]
  • "Jumper-In-Tow" involves a static line which doesn't disconnect and "you are being dragged along in the wild blue yonder."[23]
  • The "Streamer" is "dreaded" when the main chute is whistling in the wind, the chutist cuts away, and attempts to open the reserve if there is time.[23]

Records

On 16 August 1960, Joseph Kittinger, in the Excelsior III test jump, set the current 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,[24] 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.[25] 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).[26]

According to the Guinness book of records, Eugene Andreev (USSR) holds the official FAI record for the longest free-fall parachute jump (without drogue chute) after falling for 80,380 ft (24,500 m) from an altitude of 83,523 ft (25,457 m) near the city of Saratov, Russia on 1 November 1962.

See also

References

  1. ^ a b White 1968, p. 466
  2. ^ a b White 1968, pp. 462f.
  3. ^ a b c d White 1968, p. 465
  4. ^ White 1968, pp. 465f.
  5. ^ BBC: Da Vinci's Parachute Flies (2000); FoxNews: Swiss Man Safely Uses Leonardo da Vinci Parachute (2008)
  6. ^ aero.com
  7. ^ a b De Prins der Geillustreerde Bladen, February 18, 1911, p. 88-89.
  8. ^ a b c d e Parachuting at the site Divo: The Russian Book of records and achievements (Russian)
  9. ^ United States Patent US1108484 Available on-line at: http://www.freepatentsonline.com/1108484.pdf .
  10. ^ Ritter, Lisa (April/May 2010), "Pack Man", Air & Space 25 (1): 68–72, http://www.airspacemag.com 
  11. ^ May 1931, Popular Mechanics photo of observation balloon gondola with external bag parachutes used by British Royal Navy
  12. ^ Lee, Arthur Gould (1968), No parachute, London: Jarrolds, ISBN 0-09-086590-1 
  13. ^ Aviatory Life Buoy - Patent # 1192479, July 25, 1916, held by inventor Solomon Lee Van Meter, Jr http://www.vanmetre.com/Misc/Life_Buoy.pdf
  14. ^ Kentucky Aviation Pioneers Solomon Lee Van Meter Jr. (1888-1937), KET Aviation Museum Of Kentucky
  15. ^ [1]
  16. ^ [2]
  17. ^ Russian parachute of Kotelnikov (Russian)
  18. ^ Dr L. de Jong, 'Het Koninkrijk der Nederlanden in de Tweede Wereldoorlog', (Dutch language) part 3, RIOD, Amsterdam, 1969
  19. ^ Dr L. de Jong, 'Het Koninkrijk der Nederlanden in de Tweede Wereldoorlog', (Dutch language) part 10a-II, RIOD, Amsterdam, 1980
  20. ^ Pierre Marcel Lemoigne, U.S. patent no. 3,228,636 (filed: 7 November 1963; issued: 11 January 1966). Available on-line at: http://www.google.com/patents?id=XcxVAAAAEBAJ&pg=PA1&zoom=4&ie=ISO-8859-1&output=html .
  21. ^ French Web site on recent work on parachutes (in French): http://jmp-pan.blogspot.com/2008/02/historique-du-parachutisme-ascensionnel_988.html . Includes photo of Mr. Lemoigne.
  22. ^ See also: Theodor W. Knacke, "Technical-historical development of parachutes and their applications since World War I (Technical paper A87-13776 03-03)," 9th Aerodynamic Decelerator and Balloon Technology Conference (Albuquerque, New Mexico; 7–9 October 1986) (N.Y., N.Y.: American Institute of Aeronautics and Astronautics, 1986), pages 1-10.
  23. ^ a b c d Scott Royce E. "Bo". Jump School at Fort Benning (originally published in a column called DUSTOFF in the July - August 1988 Issue of the Screaming Eagle Magazine)
  24. ^ Jeffrey S. Hampton (2003-12-15). "'Hero of Aviation' speaks about record-setting free fall". The Virginian-Pilot: p. Y1. 
  25. ^ Tim Friend (1998-08-18). "Out of thin air His free fall from 20 miles (32 km) put NASA on firm footing". USA Today: p. 1D. 
  26. ^ Data of the stratospheric balloon launched on 8/16/1960 For EXCELSIOR III

Sources

External links


Translations:

Parachute

Top

Dansk (Danish)
n. - faldskærm
v. tr. - kaste ud med faldskærm
v. intr. - springe ud med faldskærm

Nederlands (Dutch)
parachute, parachuteren, aan/met een parachute neerlaten

Français (French)
n. - parachute
v. tr. - parachuter
v. intr. - parachuter

Deutsch (German)
n. - Fallschirm
v. - mit dem Fallschirm absetzen/abwerfen, mit dem Fallschirm abspringen

Ελληνική (Greek)
n. - αλεξίπτωτο
v. - πέφτω/ρίχνω με αλεξίπτωτο

Italiano (Italian)
paracadutare, paracadutarsi, paracadute

Português (Portuguese)
n. - pára-quedas (m)
v. - saltar/soltar de pára-quedas

Русский (Russian)
парашют, прыгать с парашютом

Español (Spanish)
n. - paracaídas
v. tr. - lanzar en paracaídas
v. intr. - lanzarse en paracaídas

Svenska (Swedish)
n. - fallskärm
v. - fallskärmshoppa

中文(简体)(Chinese (Simplified))
降落伞, 伞投, 伞降, 跳伞

中文(繁體)(Chinese (Traditional))
n. - 降落傘
v. tr. - 傘投
v. intr. - 傘降, 跳傘

한국어 (Korean)
n. - 낙하산 , 풍산종자, 비막
v. tr. - 낙하산으로 떨어뜨리다
v. intr. - 강하하다

日本語 (Japanese)
n. - パラシュート, 落下傘
v. - パラシュートで降下する

العربيه (Arabic)
‏(الاسم) باراشوت, مظله (فعل) ينزل بالبارشوت, يهبط‏

עברית (Hebrew)
n. - ‮מצנח‬
v. tr. - ‮הצניח‬
v. intr. - ‮צנח‬


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