Parachute

Parachute

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A parachute is a device used to slow the motion of an object through an atmosphere by creating drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...

, or in the case of ram-air parachutes, aerodynamic lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface 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 surface force parallel to the flow direction...

. Parachutes are usually made out of light, strong cloth, originally silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

, now most commonly nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

. 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 capsule
Space capsule
A space capsule is an often manned spacecraft which has a simple shape for the main section, without any wings or other features to create lift during atmospheric reentry....

s, and bombs.

Drogue chutes are used to aid horizontal deceleration of a vehicle (a fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

, or a drag racer
Drag racing
Drag racing is a competition in which specially prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly a ¼-mile straight track....

), or to provide stability (tandem free-fall, or space shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

 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.

Early Renaissance Forms



The earliest evidence for the parachute dates back to the Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

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

Only slightly later, a more sophisticated parachute was sketched by the polymath Leonardo da Vinci
Leonardo da Vinci
Leonardo di ser Piero da Vinci was an Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer whose genius, perhaps more than that of any other figure, epitomized the Renaissance...

 in his Codex Atlanticus
Codex Atlanticus
The Codex Atlanticus is a twelve-volume, bound set of drawings and writings by Leonardo da Vinci, the largest such set; its name indicates its atlas-like breadth. It comprises 1,119 leaves dating from 1478 to 1519, the contents covering a great variety of subjects, from flight to weaponry to...

 (fol. 381v) dated to ca. 1485. Here, the scale of the parachute is in a more favorable proportion to the weight of the jumper. Leonardo's canopy was held open by a square wooden frame, which alters the shape of the parachute from conical to pyramidal. It is not known whether the Italian inventor was influenced by the earlier design, but he may have learnt about the idea through the intensive oral communication among artist-engineers of the time
Renaissance technology
Renaissance technology is the set of European artifacts and customs which span the Renaissance period, roughly the 14th through the 16th century. The era is marked by profound technical advancements such as the printing press, linear perspective in drawing, patent law, double shell domes and...

. The feasibility of Leonardo's pyramidal design was successfully tested in 2000 by the British
British people
The British are citizens of the United Kingdom, of the Isle of Man, any of the Channel Islands, or of any of the British overseas territories, and their descendants...

 Adrian Nicholas
Adrian Nicholas
Adrian Nicholas was a British skydiver who completed more than 8,000 jumps in 30 countries.He is best known for his successful test of Leonardo da Vinci's parachute design, proving it to be in retrospective the world's first working parachute...

 and again in 2008 by another skydiver
Skydiver
A skydiver is a person who engages in the sport of parachuting. It may also refer to:* SkyDiver a futuristic submarine featured in the TV series UFO* "Skydiver" a carnival ride produced by Chance Morgan...

. According to the historian of technology Lynn White, these conical and pyramidal designs, much more elaborate than early artistic jumps with rigid parasols in Asia, mark the origin of "the parachute as we know it".

The Venetian
Republic of Venice
The Republic of Venice or Venetian Republic was a state originating from the city of Venice in Northeastern Italy. It existed for over a millennium, from the late 7th century until 1797. It was formally known as the Most Serene Republic of Venice and is often referred to as La Serenissima, in...

 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. A now-famous depiction of a parachute that he dubbed Homo Volans (Flying Man) appeared in his book on mechanics, Machinae Novae (1595), alongside a number of other devices and technical concepts. In 1617, Veranzio implemented his design and tested the parachute by jumping from a tower
Tower
A tower is a tall structure, usually taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires....

 in Venice
Venice
Venice is a city in northern Italy which is renowned for the beauty of its setting, its architecture and its artworks. It is the capital of the Veneto region...

. The event was documented some thirty years later by John Wilkins
John Wilkins
John Wilkins FRS was an English clergyman, natural philosopher and author, as well as a founder of the Invisible College and one of the founders of the Royal Society, and Bishop of Chester from 1668 until his death....

, founder and secretary of the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...

 in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

.

Modern parachutes






18th and 19th centuries


The modern parachute was invented in the late 18th century by Louis-Sébastien Lenormand
Louis-Sébastien Lenormand
Louis-Sébastien Lenormand was a French physicist, inventor and pioneer in parachuting. He is considered the first human to make a witnessed descent with a parachute and is also credited with coining the term parachute...

 in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan 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
Jean-Pierre Blanchard
Jean-Pierre Blanchard , aka Jean Pierre François Blanchard, was a French inventor, most remembered as a pioneer in aviation and ballooning....

 demonstrated it as a means of safely disembarking from a hot air balloon
Hot air balloon
The hot air balloon is the oldest successful human-carrying flight technology. It is in a class of aircraft known as balloon aircraft. On November 21, 1783, in Paris, France, the first untethered manned flight was made by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in a hot air...

. 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
Linen
Linen is a textile made from the fibers of the flax plant, Linum usitatissimum. Linen is labor-intensive to manufacture, but when it is made into garments, it is valued for its exceptional coolness and freshness in hot weather....

 stretched over a wooden frame, in the late 1790s, Blanchard began making parachutes from folded silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

, taking advantage of silk's strength and light weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...

. 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. The following year Franz Reichelt
Franz Reichelt
Franz Reichelt, also known as Frantz Reichelt or François Reichelt , was an Austrian-born French tailor, inventor and parachuting pioneer, now sometimes referred to as the Flying Tailor, who is remembered for his accidental death by jumping from the Eiffel Tower while testing a wearable parachute...

 fell to his death from the tower demonstrating his wearable parachute.

Also in 1911, Grant Morton
Grant Morton
Grant Morton is one of the first people to successfully attempt skydiving, and is sometimes credited with the first skydive, in 1911. Supposedly, at age 54, Morton, a veteran parachutist, made the first dive by jumping from a Wright Model B over Venice, California.-References:...

 made the first parachute jump from an airplane, a Wright Model B
Wright Model B
|-See also:-References:* * * * * * -External links:* *...

, at Venice Beach, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. 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
Gleb Kotelnikov
Gleb Yevgeniyevich Kotelnikov , was the Russian-Soviet inventor of the knapsack parachute , and braking parachute....

 invented the first knapsack parachute, although Hermann Lattemann
Hermann Lattemann
Hermann Lattemann was a German balloon pilot and inventor who experimented with an early prototype of a parachute....

 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
Tsarskoye Selo
Tsarskoye Selo is the town containing a former Russian residence of the imperial family and visiting nobility, located south from the center of St. Petersburg. It is now part of the town of Pushkin and of the World Heritage Site Saint Petersburg and Related Groups of Monuments.-History:In...

, years before it became part of St. Petersburg, Kotelnikov successfully demonstrated the braking effects of parachute by accelerating a Russo-Balt
Russo-Balt
Russo-Balt was one of the first Russian companies that produced cars between 1909 and 1923.- Russo-Baltic Wagon Corp. :...

 automobile to the top speed, and then opening a parachute attached to the back seat, thus inventing also the drogue parachute
Drogue parachute
A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, or to provide control and stability, or as a pilot parachute to deploy a larger parachute...

.

On 1 March 1912, US Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 Captain Albert Leo Stevens
Albert Leo Stevens
Albert Leo Stevens was a pioneering balloonist.-Biography:He was born on March 9, 1873 or 1877 in Cleveland, Ohio of Czech parentage. He had brother Frank Stevens ....

 made the first (attached-type) parachute jump in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 from a fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

, a Benoist
Benoist Aircraft
The Benoist Aircraft Company was an early manufacturer of aircraft in the United States. It was formed in 1912 in St Louis, Missouri by Thomas W. Benoist. Over the next five years, it would manufacture some 106 aircraft, including Benoist XIVs that would be used for the first heavier-than-air...

 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
Štefan Banic
Štefan Banič was a Slovak inventor who devised a military parachute, the first parachute ever deployed in actual use....

 from Slovakia
Slovakia
The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...

, invented the first actively used parachute, patenting it in 1913. On 21 June 1913, Georgia Broadwick became the first woman to parachute jump from a moving aircraft, doing so over Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...

.

World War One


The first military use for the parachute was for use by artillery detectors on tethered observation balloons in World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. These were tempting targets for enemy fighter aircraft
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

, 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
Hermann Göring
Hermann Wilhelm Göring, was a German politician, military leader, and a leading member of the Nazi Party. He was a veteran of World War I as an ace fighter pilot, and a recipient of the coveted Pour le Mérite, also known as "The Blue Max"...

 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. As a result, the pilot of a disabled plane only had three options: Try to ride his machine into the ground, often burning alive with it, jump from several thousand feet, or commit suicide using a standard-issued revolver.

In the UK, Everard Calthrop
Everard Calthrop
Everard Richard Calthrop was a British railway engineer and inventor. Calthrop was a notable promoter and builder of narrow gauge railways, especially of gauge, and was especially prominent in India. His most notable achievement was the Barsi Light Railway; however he is best known in his home...

, a railway engineer, and breeder of Arab horses, invented and marketed through his Aerial Patents Company a "British Parachute." Thomas Orde-Lees
Thomas Orde-Lees
Thomas Orde-Lees was a member of Sir Ernest Shackleton's Imperial Trans-Antarctic Expedition of 1914–1917, a pioneer in the field of parachuting, and was one of the first non-Japanese-born men known to have climbed Mount Fuji during the winter.-Early life:Thomas Hans Orde-Lees was born on 23...

, 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.
Solomon Lee Van Meter, Jr.
Solomon Lee Van Meter, Jr. was an American inventor, famous for inventing the first successful backpack Parachute.- Early life :...

 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. 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.

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
Erich Löwenhardt
Erich Löwenhardt was the 3rd highest German flying ace with 54 victories during the First World War, behind only Manfred von Richthofen and Ernst Udet.-Early life and service:...

 (who fell from 12000 feet (3,657.6 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 3000 ft (914.4 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.

An early brochure of the Irvin Air Chute Company credits William O'Connor as having become, on 24 August 1920 at McCook Field
McCook Field
McCook Field was an airfield and aviation experimentation station operated by the Aviation Section, U.S. Signal Corps and its successor the United States Army Air Service from 1917-1927...

 near Dayton, Ohio
Dayton, Ohio
Dayton is the 6th largest city in the U.S. state of Ohio and the county seat of Montgomery County, the fifth most populous county in the state. The population was 141,527 at the 2010 census. The Dayton Metropolitan Statistical Area had a population of 841,502 in the 2010 census...

, 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 20 October 1922. Shortly after Harris' jump, two Dayton newspaper reporters suggested the creation of the Caterpillar Club
Caterpillar Club
The Caterpillar Club is an informal association of people who have successfully used a parachute to bail out of a disabled aircraft. After authentication by the parachute maker, applicants receive a membership certificate and a distinctive lapel pin...

 for successful parachute jumps from disabled aircraft.

In 1924 Gleb Kotelnikov
Gleb Kotelnikov
Gleb Yevgeniyevich Kotelnikov , was the Russian-Soviet inventor of the knapsack parachute , and braking parachute....

 became the first parachutist to apply the soft packing of a parachute instead of a hard casing.

Beginning with Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 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. Earlier the same year, in 1930, the first Soviet mass jumps led to the development of the parachuting sport in the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

. By the time of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, large airborne forces
Airborne forces
Airborne forces are military units, usually light infantry, set up to be moved by aircraft and 'dropped' into battle. Thus they can be placed behind enemy lines, and have an ability to deploy almost anywhere with little warning...

 were trained and used in surprise attacks, as in the Battle for The Hague
Battle for The Hague
The Battle for the Hague was the first paratroop assault in history. It took place on 10 May 1940 as part of the Battle of the Netherlands between the Royal Netherlands Army and Luftwaffe Fallschirmjäger . German paratroopers dropped in and around The Hague and were given orders to capture Dutch...

, the first large scale deployment of airborne troops in military history, by the Germans (whose operation failed totally) and in 1941 Battle of Crete
Battle of Crete
The Battle of Crete was a battle during World War II on the Greek island of Crete. It began on the morning of 20 May 1941, when Nazi Germany launched an airborne invasion of Crete under the code-name Unternehmen Merkur...

 and in 1944 the Operation Market Garden
Operation Market Garden
Operation Market Garden was an unsuccessful Allied military operation, fought in the Netherlands and Germany in the Second World War. It was the largest airborne operation up to that time....

, again in Holland and again a complete failure but still the largest airborne military operation ever carried out. Aircraft crew were routinely equipped with parachutes for emergencies as well.

In 1937, drag chutes were used in aviation for the first time, by the Soviet airplanes in the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 that were providing support for the famous polar expeditions of the era, such as the first manned drifting ice station North Pole-1
North Pole-1
North Pole-1 was the first Soviet manned drifting station, primarily used for research.North Pole-1 was established on May 21, 1937, and officially opened on June 6, some from the North Pole by the expedition into the high latitudes Sever-1, led by Otto Schmidt. The expedition had been airlifted...

. The drag chute allowed to land safely on the ice-floes of smaller size.

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



Round parachutes are purely drag devices (that is, unlike the ram-air types, they provide no lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface 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 surface force parallel to the flow direction...

) and are used in military, emergency and cargo applications. These have large dome-shaped canopies made from a single layer of triangular cloth gores
Gore (segment)
A gore is a segment of a three-dimensional shape fabricated from a two-dimensional material. The term was originally used to describe triangular shapes, but is now extended to any shape that can be used to create the third dimension.-Examples:...

. 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
T-10 parachute
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...

 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. 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 (4.8 m/s). The T-11 is designed to have an average rate of descent 14% slower than the T-10D thus resulting in lower landing injury rates for jumpers. The decline in rate of descent will reduce the impact energy by almost 25% to lessen the potential for injury.



Annular and pull-down apex types


A variation on the round parachute is the pull down apex parachute. Invented by a Frenchman named Pierre-Marcel Lemoigne, 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
Rogallo wing
The Rogallo wing is a flexible type of airfoil. In 1948, Gertrude Rogallo, and her husband Francis Rogallo, a NASA engineer, invented a self-inflating flexible wing they called the Parawing, also known after them as the "Rogallo Wing" and flexible 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
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...

 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
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 are used on nuclear bombs such as the B61
B61 nuclear bomb
The B61 nuclear bomb is the primary thermonuclear weapon in the U.S. Enduring Stockpile following the end of the Cold War. It is an intermediate yield strategic and tactical nuclear weapon featuring a two-stage radiation implosion design....

 and B83
B83 nuclear bomb
The B83 nuclear weapon is a variable yield gravity bomb developed by the United States in the late 1970s, entering service in 1983. With a maximum yield of 1.2 megatons, it is currently the most powerful atomic weapon in the US arsenal...

.

Ram-air types


Most modern parachutes are self-inflating "ram-air" airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....

s known as a parafoil
Parafoil
A parafoil is a nonrigid airfoil with an aerodynamic cell structure which is inflated by the wind. Ram-air inflation forces the parafoil into a classic wing cross-section. Parafoils are most commonly constructed out of ripstop nylon....

 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
Terminal velocity
In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving....

. 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
Airlock (parachute)
A parachute airlock is a safety mechanism built into some parachute models which resist it losing its shape while open. It uses a ram air structure to stiffen each section of the outer edge....

. The first Ram-air test jump was made by Navy test jumper Joe Crotwell.

Deployment


Reserve parachutes usually have a ripcord
Ripcord (skydiving)
A ripcord is a part of a skydiving harness-container system; a handle attached to a steel cable ending in a closing pin. The pin keeps the container closed and keeps the spring-loaded pilot chute inside. When the ripcord is pulled, the container is opened and the pilot chute is released, opening...

 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
Pilot chute
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:...

. A ripcord system pulls a closing pin (sometimes multiple pins), which releases a spring-loaded pilot chute, and opens the container; the pilot chute is then propelled into the air stream by its spring, then uses the force generated by passing air to extract a deployment bag containing the parachute canopy, to which it is attached via a bridle. A hand-deployed pilot chute, once thrown into the air stream, pulls a closing pin on the pilot chute bridle to open the container, then the same force extracts the deployment bag. There are variations on hand-deployed pilot chutes, but the system described is the more common throw-out system.

Only the hand-deployed pilot chute may be collapsed automatically after deployment—by a kill line reducing the in-flight drag of the pilot chute on the main canopy. Reserves, on the other hand, do not retain their pilot chutes after deployment. The reserve deployment bag and pilot chute are not connected to the canopy in a reserve system. This is known as a free-bag configuration, and the components are often lost during a reserve deployment.

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

Paratroopers' main parachutes are usually deployed by static lines that release the parachute, yet retain the deployment bag that contains the parachute—without relying on a pilot chute for deployment. In this configuration the deployment bag is known as a direct-bag system, in which the deployment is rapid, consistent, and reliable. This kind of deployment is also used by student skydivers going through a static line
Static line
A static line is a fixed cord attached to a large, stable object. It is used for safety in construction andto open parachutes automatically for paratroopers and novice parachutists.-Use in parachuting:...

 progression, a kind of student program.

Varieties of personal ram-airs



Personal ram-air parachutes are loosely divided into two varieties: rectangular or tapered, commonly referred to as "squares" or "ellipticals" respectively. Medium-performance canopies (reserve-, BASE
BASE jumping
BASE jumping, also sometimes written as B.A.S.E jumping, is an activity that employs an initially packed parachute to jump from fixed objects...

-, 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 feet (1.5 m) tall entry gate. Current world records exceed 600 feet (182.9 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 skydiver
Skydiver
A skydiver is a person who engages in the sport of parachuting. It may also refer to:* SkyDiver a futuristic submarine featured in the TV series UFO* "Skydiver" a carnival ride produced by Chance Morgan...

s 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
Slider (parachuting)
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...

; a small rectangular piece of fabric with a grommet
Grommet
thumb|right|250px|Some rubber grommets.A grommet is a ring inserted into a hole through thin material, such as fabric. Grommets are generally flared or collared on each side to keep them in place, and are often made of metal, plastic, or rubber. They may be used to prevent tearing or abrasion of...

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

" 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
3-ring release system
The 3-ring release system is a parachute component that is widely used by sport skydivers to attach the two risers of a main parachute to the harness that bears the load under the parachute....

, and the reserve be deployed. Most skydivers also equip themselves with small barometric computers (known as an AAD or automatic activation device
Automatic activation device
Automatic Activation Device 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....

 like Cypres
Cypres
CYPRES is an acronym for Cybernetic Parachute Release System. It refers to a specific make and model of an automatic activation device , a device that automatically opens a parachute under certain circumstances. A CYPRES will usually open at a preset altitude if the rate of descent is over a...

, 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
Probability
Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...

 of an unlikely main malfunction being multiplied by the even less likely probability of a reserve malfunction. This yields an even smaller probability of a double malfunction, although the possibility of a main malfunction that cannot be cut away causing a reserve malfunction is a very real risk. In the U.S., the average fatality rate is considered to be about 1 in 80,000 jumps. Most injuries and fatalities in sport skydiving occur under a fully functional main parachute because the skydiver made an error in
judgment while flying the canopy—resulting in high-speed impact with the ground, impact with a hazard on the ground that might otherwise have been avoided, or collision with another skydiver under canopy.

Parachute malfunctions



Below are listed malfunctions specific to round-parachutes. For malfunctions specific to square parachutes, see Malfunction (parachuting)
Malfunction (parachuting)
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.-Pilot chute in tow:...

.
  • 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 suitable for a woman of Mae West
    Mae West
    Mae West was an American actress, playwright, screenwriter and sex symbol whose entertainment career spanned seven decades....

    's proportions.
  • "Squidding" occurs when a parachute fails to inflate properly and its sides are forced inside the canopy. This kind of malfunction occurred during parachute testing for the Mars Exploration Rover
    Mars Exploration Rover
    NASA's Mars Exploration Rover Mission is an ongoing robotic space mission involving two rovers, Spirit and Opportunity, exploring the planet Mars...

    .
  • A "cigarette roll" occurs when a parachute deploys fully from the bag but fails to open. The parachute then appears as a vertical column of cloth (in the general shape of a cigarette), providing the jumper with very little drag. It is caused when one skirt of the canopy, instead of expanding outward, is blown against the opposite skirt. The column of nylon fabric, buffeted by the wind, rapidly heats from the friction of the nylon rubbing against nylon and can melt the fabric and fuse it together, 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
    Barber's pole
    A barber's pole is a type of sign used by barbers to signify the place or shop where they perform their craft. The trade sign is, by a tradition dating back to the Middle Ages, a staff or pole with a helix of colored stripes...

    " describes having a mess of lines tangled “behind your head and you have to cut away your main chute and pull your reserve.”
  • The "Horseshoe
    Horseshoe
    A horseshoe, is a fabricated product, normally made of metal, although sometimes made partially or wholly of modern synthetic materials, designed to protect a horse's hoof from wear and tear. Shoes are attached on the palmar surface of the hooves, usually nailed through the insensitive hoof wall...

    " when you are wrapped in a chute, and pull the reserve immediately, without cutting away the main chute.
  • "Jumper-In-Tow" involves a static line which doesn't disconnect and "you are being dragged along in the wild blue yonder."
  • 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.

Records


On 16 August 1960, Joseph Kittinger
Joseph Kittinger
Joseph William Kittinger II is a former Command Pilot and career military officer in the United States Air Force. He is most famous for his participation in Project Manhigh and Project Excelsior, holding the records for having the highest, fastest and longest skydive, from a height greater than...

, in the Excelsior III test jump, set the current world record for the highest parachute jump. He jumped from a balloon
Balloon
A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

 at an altitude of 102800 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
Free-fall
Free fall is any motion of a body where gravity is the only force acting upon it, at least initially. These conditions produce an inertial trajectory so long as gravity remains the only force. Since this definition does not specify velocity, it also applies to objects initially moving upward...

, if falling with a stabilizer chute is counted as free-fall. At an altitude of 17500 feet (5,334 m), Kittinger opened his main chute and landed safely in the New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 desert. The whole descent took 13 minutes and 45 seconds. During the descent, Kittinger experienced temperatures as low as -94 °F. In the free-fall stage, he reached a top speed of 614 mph (988 km/h or 274 m/s).

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

  • Free fall
    Free fall
    Free fall is any motion of a body where gravity is the only force acting upon it, at least initially. These conditions produce an inertial trajectory so long as gravity remains the only force. Since this definition does not specify velocity, it also applies to objects initially moving upward...

  • Parachuting
    Parachuting
    Parachuting, also known as skydiving, is the action of exiting an aircraft and returning to earth with the aid of a parachute. It may or may not involve a certain amount of free-fall, a time during which the parachute has not been deployed and the body gradually accelerates to terminal...

  • Parachute landing fall
    Parachute Landing Fall
    A parachute landing fall is a safety technique that allows a parachutist to land safely and without injury. The technique is performed by paratroopers and novice recreational parachutists when using round parachutes deployed by static line....

  • Paratrooper
    Paratrooper
    Paratroopers are soldiers trained in parachuting and generally operate as part of an airborne force.Paratroopers are used for tactical advantage as they can be inserted into the battlefield from the air, thereby allowing them to be positioned in areas not accessible by land...

  • Landing
    Landing
    thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...


External links