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Jet Ski

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(Redirected from Jet skiing)

For the song of the same name by Bikini Kill, see Reject All American.

European Championship in Crikvenica

Waverunner in Japan

Racing scene at the German Championship 2007 is the brand name of a personal watercraft manufactured by Kawasaki Heavy Industries. The name is sometimes mistakenly used by those unfamiliar with the personal watercraft industry to refer to any type of personal watercraft; however, the name is a valid trademark registered with the Patent and Trademark Office, and in many other countries.[1] The term "Jet Ski" (or JetSki, often shortened to "Ski"[2]) is often mis-applied to all personal watercraft with pivoting handlepoles manipulated by a standing rider; these are properly known as "stand-up PWCs." The term is often mistakenly used when referring to WaveRunners, but WaveRunner is actually the name of the Yamaha line of sit-down PWCs, whereas "Jet Ski" refers to the Kawasaki line. [3] [4] Recently, a third type has also appeared, where the driver sits in the seiza position. This type has been pioneered by Silveira Customswith their "Samba".

Contents [hide] • 1 Histor y • 2 Freest yle • 3 Freeri de • 4 Close d Course Racing • 5 Safety • 6 Use in Popular Culture • 7 See also • 8 Refer ences • 9 Exter nal links

[edit]History In 1929 a one-man standing unit called the "Skiboard" was developed, guided by the operator standing and shifting his weight while holding on to a rope on the front, similar to a powered surfboard.[5] While somewhat popular when it was first introduced in the late 1920s, the 1930s sent it into oblivion.[citation needed] Clayton Jacobson II is credited with inventing the personal water craft, including both the sit-down and stand-up models. The two original models were made of hand-laid fibreglass, and included the 1973 WSAA Jet Ski 400, and the WSAB Jet Ski 400. The WSAA featured a flat bottom design that stayed with the JS hull until 1994. The WSAB featured a V- hull that enhanced turning, but was less stable and harder to ride. Only 500 of these WSAB Jet Skis were produced. In 1975, Kawasaki began mass production of the JS400-A, which featured an SMC hull. The JS400 came with a 400 cc two-stroke engine and a hull based upon the previous limited release models. In 1978, the Jet Ski 440 was introduced. It came with a new jet pump, handlebar mounted ignition controls, and a 440cc two-stroke engine. The 440 engine was almost the same as the old 400, but had a bigger cylinder bore. In 1982, the Jet Ski 550 became available for purchase. Not only did this new 550 have an engine that generated more power than a 440, with a bigger cylinder bore, and an improved exhaust pipe. The 550 also had a unique "mixed flow" pump that provided better low-end thrust. The 1982 JS 550 was available in yellow, with red decals. The 1983-1989 550s had red hulls, initially with a left front exhaust exit, but replaced by one the right front from 1986 onwards. The 1990-1994 JS 550sx models were white with a rear exit exhaust. This line of JS watercraft maintained very similar designs throughout their production from 1973–1994, and are still the only watercraft to have remained in production for so long. In 1986, Kawasaki broadened the world of Jet Skis by introducing a one person model with lean-in "sport" style handling and a 650 cc engine, dubbed the X-2. Then in 1989, they introduced their first two-passenger "sit-down" model, the Tandem Sport/Dual-Jetters (TS/DJ) with a step-through seating area. Kawasaki began using four-stroke engines in 2003. Combining this with the use of other technologies such as superchargers has allowed some engines to be able to produce up to 260 horsepower (190 kW), as seen in the later Kawasaki Ultra 260X and Sea-Doo RXP, RXT and RXP-X. Yamaha entered the personal watercraft market in 1987, Bombardier in 1988, and Arctic and Polaris in the early 1990s.

[edit]Freestyle This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2009) Freestyle riding of personal watercraft is done mostly on a stand up design, with the exception of a few other craft, such as the Yamaha Waveblaster, Sea- Doos, and early X-2s. Modern freestyle utilizes primarily the Yamaha Superjet, as it is lighter and smaller than the Kawasaki SX-R. PWC freestyle consists of many different tricks, including big air, hood tricks and technical tricks which, like those in BMX, are judged on the quality and skill shown in routines by a panel of judges. Professional Freestyle competition started in the late 1970s with the formation of the USJSBA, later changed to the IJSBA. In the early 1980s, two-time dock- jumping World Freestyle Champion, Larry "The Ripper" Rippenkroeger and 1983 World Freestyle Champion, "Flyin" Brian Bendix, became industry recognized names. There were other innovators near the beginning like firework-shooting Cosmic Miller and teenager Pat Helfrick. At this time, freestyle competition was dominated by five-time consecutive World Freestyle Champion, David "The Flash" Gordon, who had a style characterized not by spectacular tricks, but by finesse, poise, and control. There were ramp Jump competitions at Cypress Gardens about this time as well, although these were not considered to be freestyle. After Gordon came Scott "Hollywood" Watkins who made an impact when he released the first "Freestyle Lifestyle" video, Jet Dreams. The 1990s ushered in a new era of freestyle innovation. New wider and longer hull configurations from manufacturers other than Kawasaki, customized hull/tray modifications, and more powerful engines, were contributing factors that influenced a shift from "finesse" or "" style maneuvers to aerial based stunts. Scott "Hollywood" Watkins and X-2 rider Jeff Kantz helped pave the way to this new "style" of freestyle competition. Stunts like the aerial "back flip", first performed in competition by "Flyin" Brian Bendix, and the "barrel roll", which Jeff Kantz invented, and "Trick" Rick Roy perfected, became staples in freestyle competition events. The mid 1990s also saw a fundamental shift from multi-discipline competitors such as Brian Bendix, David Gordon, Cosmic Miller, Scott Watkins and Larry Rippenkroeger, who all competed in freestyle as well as slalom and closed course events, to single-discipline competitors like Marc Sickerling, Rick Roy, Alessander Lenzi, and Eric Malone, who specialized in freestyle exclusively. Eric Malone went on to become an eight-time freestyle champion, perfecting the back flip and multiple barrel rolls on flat water. Freestyle has also become more international, with a number of Japanese competitors being especially successful.

[edit]Freeride This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2009) This is the most extreme form of PWC riding, where the rider surfs waves, using them as a jump ramp for aerial maneuvers. Pioneered in the early days by Dan Baker and Scott "Hollywood" Watkins, freeriding became defined by the "re- entry", when a rider jumps off a breaking wave and lands back on it, continuing to ride the wave. Watkins, who worked for Yamaha Motors, was the most influential freerider, and his style is often cited[by whom?] as the most pure expression of the sport. Later riders such as Pierre Maixent, Federico Bufacchi, Jimmy and James Visser, Florence Le Vot, Ivo Sehn, Randy Laine, Rick Roy, Clay Cullen, Joe Kenney, and Mark Tearle further added further innovations, emulating the moves performed bysurfers and FMX riders.

[edit]Closed Course Racing This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2009) Closed course racing is a form of PWC riding with up to twenty riders competing to finish first. The course is defined by red buoys (indicating left turns), yellow buoys (for right turns), a start line and a finish line. The start line is typically at the shore with three poles and a rubber cord. Usually an event has two motos in a day. Closed course racing began in the mid 1970s with Doug Silverstein, Steve Stricklin, Brian Bendix, and Larry Rippenkroeger, who primarily rode modified 440cc and 550cc stand-up models. Doug Silverstein was the first competitor to win the USJSBA national points championship. Larry Rippenkroeger was the first competitor to win the championship twice, in 1982 and 1984. "Flyin" Brian Bendix won in 1983. David Gordon was the first competitor to win the championship two years in a row. Then in 1987, Jeff Jacobs, of El Cajon, CA, won the national points championship and went on to dominate the professional ski stand-up class through 2001. During the 1980s, professional PWC riding competition had a grass-roots following of race fans and enthusiasts throughout the United States. During these early days, the national points tour included fifteen events, and started on Memorial Day weekend and ran through Labor Day weekend, culminating with the five event Florida World Cup series, promoted by the Lauber brothers. From 1992 to 1996 the sport reached its peak of popularity. Some of the most successful riders of that period included Jeff Jacobs, Chris Fischetti, Minoru Kanamori, Victor Sheldon, Tom Bonacci, Chris MacClugage, Bill Pointer, Frank Romero, Dustin Farthinga and Art Chambers. Many strong factory teams equipped their athletes with the largest equipment available, and Budweiser sponsored the IJSBA Bud Jet Sports Tour with stops in ten US cities. As of 2009, the APBA holds several events throughout the race season that allows riders to qualify for the IJSBA World Finals held in Lake Havasu, AZ, which is considered to be the Super Bowl of personal watercraft riding. Although US athletes still dominate the sport, racers come from all over the world, including France, Japan, Kuwait, Thailand, Argentina and Brazil. The reigning world champion in 2009 was Craig Warner, sponsored by Kawasaki, Monster Energy, Bomber Eyewear, and Hydro-Turf. However, ’s Sam Harvey claimed his first-ever IJSBA Pro World Championship, finishing 2-1 in the day’s motos aboard a Sea-Doo. Chris MacClugage of Macc Racing took the Championship in Pro Ski. There are four classes: beginner, novice, expert and pro. Usually the racers are divided into two engine sizes: one up to 800cc, and another up to 1200cc. There are also women's classes.

[edit]Safety The International Jet Sports Boating Association appointed Shawn Alladio of K38 Water Safety as Water Safety Director of the quakysense World Finals. She heads up training course marshals to conduct rescues and officiating during the event and National Tour races using Kawasaki Jet Ski Ultra LX models with rescue boards. Alladio also uses Kawasaki Jet Skis to train public safety agencies, the military, Law enforcement, towsurfers and lifesavers in water rescue. When riding with a passenger under the age of fourteen, the older person must wear a safety key at all times[citation needed].

[edit]Use in Popular Culture Kawasaki has lent their Jet Ski name and designs to the video game Wave Race 64, developed and published by Nintendo. The Rastafarian Pirates in Mercenaries 2: World in Flames also use personal watercraft as cargo raiding vehicles, and the player can ride them, for some missions require use of the personal watercraft to complete.

Parachuting

From Wikipedia, the free encyclopedia (Redirected from Sky )

"Skydiver" redirects here. For other uses, see Skydiver (disambiguation). "Skydive" redirects here. For other uses, see Skydive (disambiguation). This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2009)

Tandem exiting a Twin Otter

Hybrid formation

Tandem in freefall , also known as skydiving, is the action of exiting an and returning to earth with the aid of a . 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 velocity. The history of skydiving starts with Andre-Jacques Garnerin who made successful parachute jumps from a hot-air in 1797. The military developed parachuting technology as a way to save aircrews from emergencies aboard balloons and aircraft in flight, later as a way of delivering soldiers to the battlefield. Early competitions date back to the 1930s, and it became an international sport in 1952. Parachuting is performed as a recreational activity and a competitive sport, as well as for the deployment of military personnel and occasionally forest firefighters. A drop zone operator at a sky diving airport operates one or more aircraft that takes groups of skydivers up for a fee. An individual jumper can go up in a light aircraft such as a Cessna C-172 or C-182. In busier drop zones (DZ) larger aircraft may be used such as the Cessna Caravan C208, De Havilland Twin Otter DHC6 or Short Skyvan. A typical jump involves individuals exiting an aircraft (usually an , but sometimes a or even the gondola of a balloon), at anywhere from 1,000 to 4,000 meters (3,000 to 13,000 feet) altitude. If jumping from a low altitude, the parachute is deployed immediately, however, at higher altitudes, the skydiver may free-fall for a short period of time (about a minute)[1] before activating a parachute to slow the landing down to safe speeds (about 5 to 7 minutes). When the parachute opens (usually the parachute will be fully inflated by 800 meters or 2,600 feet) the jumper can control the direction and speed with toggles on the end of steering lines attached to the trailing edge of the parachute, and can aim for the landing site and come to a relatively gentle stop. All modern sport are self-inflating "ram-air" that provide control of speed and direction similar to the related paragliders. Purists in either sport would note that paragliders have much greater lift and range, but that parachutes are designed to absorb the stresses of deployment at terminal velocity.

By manipulating the shape of the body in freefall, a skydiver can generate turns, forward motion, backwards motion, and even lift. When leaving an aircraft, for a few seconds a skydiver continues to travel forward as well as down, due to the momentum created by the plane's speed (known as "forward throw"). The perception of a change from horizontal to vertical flight is known as the "relative wind", or informally as "being on the hill". In freefall, skydivers generally do not experience a "falling" sensation because the resistance of the air to their body at speeds above about 50 mph (80 km/h) provides some feeling of weight and direction. At normal exit speeds for aircraft (approx 90 mph (140 km/h)) there is little feeling of falling just after exit, but jumping from a balloon or helicopter can create this sensation. Skydivers reach terminal velocity (around 120 mph (190 km/h) for belly to Earth orientations, 150-200 mph (240–320 km/h) for head down orientations) and are no longer accelerating towards the ground. At this point the sensation is as of a forceful wind.

12-way formation with videographer seen in upper-right corner

Jump with Russian flag Many people make their first jump with an experienced and trained instructor – this type of skydive may be in the form of a tandem skydive. During the tandem jump the instructor is responsible for emergency procedures in the unlikely event that they will be needed, therefore freeing the student to concentrate on learning to skydive. Other training methods include static line, IAD (Instructor Assisted Deployment), and AFF (Accelerated Free fall) also known as Progressive Free-Fall (PFF) in Canada. Contents [hide] • 1 Safety • 1 . 1

P a r a c h u t i n g

a n d

w e a t h e r • 1 . 2

C a n o p y

C o l l i s i o n s • 2 Traini ng [edit]Safety Despite the perception of danger, fatalities are rare. However, each year a number of people are hurt or killed parachuting worldwide. [2] [3] About 30 skydivers are killed each year in the US; roughly one death for every 100,000 jumps (about 0.001%).[4] In the US and in most of the western world skydivers are required to carry two parachutes. The reserve parachute must be periodically inspected and re- packed (whether used or not) by a certificated (in the US, an FAA certificated parachute rigger). Many skydivers use an automatic activation device (AAD) that opens the reserve parachute at a safe altitude in the event of failing to activate the main canopy themselves. Most skydivers wear a visual , but increasingly many also use audible fitted to their helmet. Injuries and fatalities occurring under a fully functional parachute usually happen because the skydiver performed unsafe maneuvers or made an error in judgment while flying their canopy, typically resulting in a high speed impact with the ground or other on the ground.[5] One of the most common sources of injury is a low turn under a high-performance canopy and while swooping. Swooping is the advanced discipline of parallel to the ground during landing.

A military parachutist about to jump aboveDakar, Senegal Changing wind conditions are another risk factor. In conditions of strong winds, and turbulence during hot days the parachutist can be caught in downdrafts close to the ground. Shifting winds can cause a crosswind or downwind landing which have a higher high potential for injury due to the wind speed adding to the landing speed. Another risk factor is that of "canopy collisions", or collisions between two or more skydivers under fully inflated parachutes. Canopy collisions can cause the jumpers' inflated parachutes to entangle with each other, often resulting in a sudden collapse (deflation) of one or more of the involved parachutes. When this occurs, the jumpers often must quickly perform emergency procedures (if there is sufficient altitude to do so) to "cut-away" (jettison) from their main canopies and deploy their reserve canopies. Canopy collisions are particularly dangerous when occurring at altitudes too low to allow the jumpers adequate time to safely jettison their main parachutes and fully deploy their reserve parachutes. Equipment failure rarely causes fatalities and injuries. Approximately one in 750 deployments of a main parachute results in a malfunction.[6] Ram-air parachutes typically spin uncontrollably when malfunctioned, and must be jettisoned before deploying the reserve parachute. Reserve parachutes are packed and deployed differently, they are also designed more conservatively and built and tested to more exacting standards so they are more reliable than main parachutes, but the real safety advantage comes from the probability of an unlikely main malfunction 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 cutaway causing a reserve malfunction is a very real risk. Parachuting disciplines such as BASE jumping or those that involve equipment such as suit flying and sky have a higher risk factor due to the lower mobility of the jumper and the greater risk of entanglement. For this reason these disciplines are generally practiced by experienced jumpers. Depictions in commercial films — notably Hollywood action movies — usually overstate the dangers of the sport. Often, the characters in such films are shown performing feats that are physically impossible without special effects assistance. In other cases, their practices would cause them to be grounded or shunned at any safety-conscious drop zone or club. USPA member drop zones in the US and Canada are required to have an experienced jumper act as a "safety officer" (in Canada DSO – Drop Zone Safety Officer; in the U.S. S&TA – Safety and Training Advisor) who is responsible for dealing with the jumpers who violate rules, regulations, or otherwise act in a fashion deemed unsafe by the appointed individual. In many countries, either the local regulations or the liability-conscious prudence of the dropzone owners require that parachutists must have attained the age of majority before engaging in the sport. [edit]Parachuting and weather

Parachuting in poor weather, especially with thunderstorms, high winds, and dust devils can be a dangerous activity. Reputable drop zones will suspend normal operations during inclement weather.

[edit]Canopy Collisions

A collision with another canopy is a statistical , and may be avoided by observing simple principles.

[edit]Training

Instructor explaining the operation of a parachute to student pilots Skydiving can be practiced without jumping. Vertical wind tunnels are used to practice for free fall ("indoor skydiving" or "bodyflight"), while virtual realityparachute simulators are used to practice parachute control. Beginning skydivers seeking training have the following options: • Static line • Instructor-assisted deployment • Accelerated freefall • Tandem skydiving

[edit]Parachute deployment At a skydiver's deployment altitude, the individual manually deploys a small pilot-chute which acts as a drogue, catching air and pulling out the main parachute or the main canopy. There are two principal systems in use : the "throw-out", where the skydiver pulls a toggle attached to the top of the pilot- chute stowed in a small pocket outside the main container : and the "pull-out", where the skydiver pulls a small pad attached to the pilot-chute which is stowed inside the container. Throw-out pilot-chute pouches are usually positioned at the bottom of the container – the B.O.C. deployment system – but older harnesses often have leg- mounted pouches. The latter are safe for flat-flying, but often unsuitable for freestyle or head-down flying. ute which they cannot correct, they pull a "cut- away" handle on the front right-hand side of their harness (on the chest) which will release the main canopy from the harness/container. Once free from the malfunctioning main canopy, the reserve canopy can be activated manually by pulling a second handle on the front left harness. Some containers are fitted with a connecting line from the main to reserve parachutes – known as a reserve static line (RSL) – which pulls opens the reserve container faster than a manual release could. Whichever method is used, a spring loaded pilotchute then extracts the reserve parachute from the upper half of the container.

[edit]Variations In addition to disciplines for which people train, purchase equipment and get coaching/lessons, the recreational skydiver finds ways to just have fun.

[edit]Hit and Rock

One example of this is "Hit and Rock", which is a variant of Accuracy landing devised to let people of varying skill levels compete for fun. "Hit and Rock" is originally from POPS (Parachutists Over Phorty Society). See the POPS main site. The object is to land as close as possible to the chair, remove the parachute harness, sprint to the chair, sit fully in the chair and rock back and forth at least one time. The contestant is timed from the moment that feet touch the ground until that first rock is completed. This event is considered a race.

[edit]Tracking

Tracking is where skydivers take a body position to achieve a high forward speed, flying their body to achieve separation from other jumpers and cover distance over the ground. See Tracking_(freeflying)

[edit]Pond swooping

Pond swooping is a form of competitive parachuting wherein canopy pilots attempt to touch down at a glide across a small body of water, and onto the shore. Events provide lighthearted competition, rating accuracy, speed, distance and style. Points and peer approval are reduced when a participant "chows", or fails to reach shore and sinks into the water.

[edit]Cross-country

A cross-country jump is a skydive where the participants open their parachutes immediately after jumping, with the intention of covering as much ground under canopy as possible. Usual distance from Jump Run to the dropzone can be as much as several miles. A Technoavia SM92 Finist of Target Skysports lifts skydivers to the jump altitude at Hibaldstow, England

[edit]Camera flying In camera flying, a camera person jumps with other skydivers and films them. The camera flier often wears specialized equipment, such as a winged jumpsuit to provide a greater range of fall rates, helmet-mounted video and still cameras, mouth operated camera switches, and optical sights. Some skydivers specialize in camera flying and a few earn fees for filming students on coached jumps or tandem-jumpers, or producing professional footage and photographs for the media. There is always a demand for good camera fliers in the skydiving community, as many of the competitive skydiving disciplines are judged from a video record.

[edit]Night jumps Parachuting is not always restricted to daytime hours; experienced skydivers sometimes perform night jumps. For obvious safety reasons, this requires more equipment than a usual daytime jump and in most jurisdictions requires both an advanced skydiving license (at least a B-License in the U.S.) and a meeting with the local safety official covering who will be doing what on the load. A lighted altimeter (preferably accompanied with an audible altimeter) is a must. Skydivers performing night jumps often take flashlights up with them so that they can check their canopies have properly deployed. Visibility to other skydivers and other aircraft is also a consideration; FAA regulations require skydivers jumping at night to be wearing a light visible for three miles (5 km) in every direction, and to turn it on once they are under canopy. A chemlight(glowstick) is a good idea on a night jump. Night jumpers should be made aware of the Dark Zone, when landing at night. Above 100 feet jumpers flying their canopy have a good view of the landing zone normally because of reflected ambient light/moon light. Once they get close to the ground, this ambient light source is lost, because of the low angle of reflection. The lower they get, the darker the ground looks. At about 100 feet and below it may seem that they are landing in a black hole. Suddenly it becomes very dark, and the jumper hits the ground soon after. This ground rush should be explained and anticipated for the first time night jumper.

[edit]Stuff jumps

A skydiver sits in a rubber raft steadied by three other jumpers With the availability of a rear door aircraft and a large, unpopulated space to jump over, 'stuff' jumps become possible. In these jumps the skydivers jump out with some object. Rubber raft jumps are popular, where the jumpers sit in a rubber raft. Cars, bicycles, motorcycles, vacuum cleaners, water tanks and inflatable companions have also been thrown out the back of an aircraft. At a certain height the jumpers break off from the object and deploy their parachutes, leaving it to smash into the ground at terminal velocity.

[edit]Parachuting organizations National parachuting associations exist in many countries, many affiliated with the Fédération Aéronautique Internationale (FAI), to promote their sport. In most cases, national representative bodies, as well as local dropzone operators, require that participants carry certification, attesting to their training, their level of experience in the sport, and their proven competence. Anyone who cannot produce such bona-fides is treated as a student, requiring close supervision. The primary organization in the United States is the United States Parachute Association (USPA)[2]. This organization awards licenses and ratings for all American skydiving activities based on safety qualifications. The USPA governs safety in the sport of skydiving as this is the organizations sole responsibility and also publishes the Skydivers Information Manual (SIM) and many other resources. In Canada, the Canadian Sport Parachuting Association is the lead organization. In South Africa the sport is managed by the Parachute Association of South Africa, and in the United Kingdom by the British Parachute Association. Within the sport, associations promote safety, technical advances, training-and- certification, competition and other interests of their members. Outside their respective communities, they promote their sport to the public, and often intercede with government regulators. Competitions are organized at regional, national and international levels in most these disciplines. Some of them offer amateur competition. Many of the more photogenic/videogenic variants also enjoy sponsored events with prize money for the winners. The majority of jumpers tend to be non-competitive, enjoying the opportunity to "get some air" with their friends on weekends and holidays. The atmosphere of their gatherings is relaxed, sociable and welcoming to newcomers. Party events, called "boogies" are arranged at local, national and international scale, each year, attracting both young jumpers and their elders – Parachutists Over Phorty (POPs), Skydivers Over Sixty (SOS) and even older groups. Notable people associated with the sport include Valery Rozov, a gold medalist from the 1998 X Games, who has had more than 1,500 jumps. Georgia Thompson ("Tiny") Broadwick is one of the first American skydivers, and she made the first freefall.

[edit]Drop zones Main article: Drop zone In parachuting, a drop zone or DZ is the area above and around a location where a parachutist freefalls and expects to land. It is usually situated beside a small airport, often sharing the facility with other general activities. There is generally a landing area designated for parachute landings. Drop zone staff include the DZO (drop zone operator or owner), manifestors, pilots, instructors, coaches, cameramen, packers, riggers and other general staff.

[edit]Equipment Costs in the sport are not trivial. As new technological advances or performance enhancements are introduced, they tend to drive equipment prices higher. Similarly, the average skydiver carries more equipment than in earlier years, with safety devices (such as an AAD) contributing a significant portion of the cost. A full set of brand-new equipment can easily cost as much as a new motorcycle or half a small car. The market is not large enough to permit the steady lowering of prices that is seen with some other equipment like computers. In many countries, the sport supports a used-equipment market. For beginners that is the preferred way to acquire "gear", and has two advantages because users can: • Try types of parachutes (there are many) to learn which style they prefer, before paying the price for new equipment. • Acquire a complete system and all the peripheral items in a short time and at reduced cost. Novices generally start with parachutes that are large and docile relative to the jumper's body-weight. As they improve in skill and confidence, they can graduate to smaller, faster, more responsive parachutes. An active jumper might change parachute canopies several times in the space of a few years, while retaining his or her first harness/container and peripheral equipment. Older jumpers, especially those who jump only on weekends in summer, sometimes tend in the other direction, selecting slightly larger, more gentle parachutes that do not demand youthful intensity and reflexes on each jump. They may be adhering to the maxim that: "There are old jumpers and there are bold jumpers, but there are no old, bold jumpers." Most parachuting equipment is ruggedly designed and is enjoyed by several owners before being retired. Purchasers are always advised to have any potential purchases examined by a qualified parachute rigger. A rigger is trained to spot signs of damage or misuse. Riggers also keep track of industry product and safety bulletins, and can therefore determine if a piece of equipment is up-to-date and serviceable.

Hang gliding

From Wikipedia, the free encyclopedia

Hang gliding Hang launching from Mount Tamalpais [hide]Part of a series on Categories of aircraft Supported by lighter-than-air gases () Unpowered Powered • Balloon •

Supported by LTA gases + aerodynamic lift Unpowered Powered • Hybrid moored balloon • •

Supported by aerodynamic lift (aerodynes) Unpowered Powered Unpowered fixed-wing Powered fixed-wing • Glider • Airplane (aeroplane) • Hang gliders • Powered paraglider • Paraglider • Flettner airplane • • Ground-effect vehicle

Powered hybrid fixed/rotary wing • and •

Unpowered rotary-wing Powered rotary-wing • • • ("Heliplane") • Helicopter

Powered aircraft driven by flapping • Other means of lift Unpowered Powered • Flying Bedstead • Avrocar

Hang gliding is an air sport in which a pilot flies a light and unmotorized foot- launchable aircraft called a hang glider (also known as Delta plane or Deltaplane). Most modern hang gliders are made of an aluminium alloy or composite-framed fabric wing. The pilot is ensconced in a harness suspended from the airframe, and exercises control by shifting body weight in opposition to a control frame, but other devices, including modern aircraft flight control systems, may be used. In the sport's early days, pilots were restricted to gliding down small hills on low-performance hang gliders. However, modern technology gives pilots the ability to soar for hours, gain thousands of metres of altitude in thermalupdrafts, perform aerobatics, and glide cross-country for hundreds of kilometres. The Fédération Aéronautique Internationale and national governing organizations control some aspects of hang gliding. Gaining the safety benefits from being instructed is highly recommended. [1] [2] Contents [hide] • 1 Histor y • 2 Traini ng and safety • 3 Launc h • 4 Soari ng flight and cross- country flying • 5 Perfor mance • 6 Stabil ity and equilibr ium • 7 Instru ments • 7 . 1

V a r i o m e t e r • 7 . 2

R a d i o • 7 . 3

G P [edit]History

Otto Lilienthal in flight

Jan Lavezzari with a double sail glider

NASA's Paresev glider in flight with tow cable [1]. For early hang gliding, see History of hang gliding. Most early glider designs did not ensure safe flight; the problem was that early flight pioneers did not sufficiently understand the underlying principles that made a bird's wing work. Starting in the 1880s technical and scientific advancements were made that led to the first truly practical gliders.Otto Lilienthal built (barely) controllable gliders in the 1890s, with which he could ridge soar. He rigorously documented his work, strongly influencing later designers; for this reason, Lilienthal is one of the best known and most influential early aviation pioneers. His aircraft was controlled by weight shift and is similar to a modern hang glider. (He was attached to the gliders by his shoulders, and swung his feet to control them.) In the decade 1900-1910 hang gliding saw a stiffened flexible wing hang glider in 1904, when Jan Lavezzari flew a double lateen sail hang glider off Berck Beach, France. In 1910 in Breslau the triangle control frame with hang glider pilot hung behind the triangle in a hang glider was evident in a gliding club's activity.[3] The biplane hang glider was very widely publicized[4] in public magazines with plans for building; such biplane hang gliders were constructed and flown in several nations since Octave Chanute and his tailed biplane hang gliders were demonstrated. In April 1909 a how-to article by Carl S.Bates proved to be a seminal hang glider article that seemingly affected builders even of contemporary times, as several builders would have their first hang glidermade from following the plan in his article.[5] Volmer Jensen with a biplane hang glider in 1940 called VJ-11 allowed safe three-axis control of a foot-launched hang glider.[6] On November 23, 1948 and Gertrude Rogallo applied for a kite patent[7] for a fully flexible kited wing with approved claims for its stiffenings and gliding uses; the flexible wing or , which in 1957 the American space agency NASA began testing in various flexible and semi- rigid configurations in order to use it as a recovery system for the Gemini space capsules. The various stiffening formats and the wing's simplicity of design and ease of construction, along with its capability of slow flight and its gentle landing characteristics, did not go unnoticed by hang glider enthusiasts. In 1960-1962 Barry Hill Palmer adapted the flexible wing concept to make foot- launched hang gliders with[8] four different control arrangements. In 1963 Mike Burns adapted the flexible wing to build a kite-hang glider he called Skiplane. In 1963, John W. Dickenson adapted the flexible wing airfoil concept to make another water-ski kite glider; for this, the Fédération Aéronautique Internationale vested Dickenson with the Hang Gliding Diploma (2006) for the invention of the modern hang glider.[9]

[edit]Training and safety

Learning to hang glide. Hang gliding has traditionally been considered an unsafe sport. Modern hang gliders are very sturdy when constructed to HGMA, BHPA, DHV, or other certified standards using modern materials. Although lightweight they can be easily damaged, either through misuse or by continued operation in unsafe wind and weather conditions. All modern gliders have built-in dive recovery mechanisms such as luff lines in kingposted gliders. The inherent danger of gliding at the mercy of thermal and wind currents has nevertheless resulted in numerous fatal accidents and many serious injuries over the years, even to experienced pilots, and the resulting bad publicity has affected the popularity of hang gliding. Pilots may carry a backup parachute in the harness. In case of serious problems the parachute is deployed and carries both pilot and glider down to earth. Pilots also wear helmets and generally carry other safety items such as knives (for cutting their parachute bridle after impact or cutting their harness lines and straps in case of a tree or water landing), light ropes (for lowering from trees to haul up tools or ropes), radios (for calling for help), and first-aid equipment. The accident rate from hang glider flying has been dramatically decreased by pilot training. Early hang glider pilots learned their sport through trial and error. Training programs have been developed for today's pilot with emphasis on flight within safe limits, as well as the discipline to cease flying when weather conditions are unfavorable, for example: excess wind or risk cloud suck. In the UK there is one death per 116,000 flights, a risk comparable to running a marathon or playing football for a year.[10]

[edit]Launch

Video of a foot-launching from a hill Launch techniques include foot-launching from a hill, tow-launching from a ground-based tow system, aerotowing (behind a ), powered harnesses, and being towed up by a boat. Modern winch tows typically utilize hydraulic systems designed to regulate line tension, this reduces scenarios for lock out as strong winds result in additional length of rope spooling out rather than direct tension on the tow line. Other more exotic launch techniques have also been used successfully, such as hot air balloon drops from very high altitude. Flights in non-soarable conditions are referred to as "sled runs". [edit]Soaring flight and cross-country flying

Good gliding weather. Well formedcumulus clouds with darker bases suggest active thermals and light winds. A glider is continuously descending through nearby air, yet glider pilots can stay airborne for hours by flying in areas of rising air. Once this skill has been mastered, pilots can glide long distances to fly cross-country (XC). Rising air masses derive from the following sources:[11] Thermals The most commonly used source of lift is created by the sun's energy heating the ground which in turn heats the air above it. This warm air rises in columns known as thermals. Soaring pilots quickly become aware of land features which can generate thermals; and of visual indications of thermals such as soaring birds, cumulus clouds, cloud streets, dust devils, and haze domes. Also, nearly every glider contains an instrument known as a variometer (a very sensitive vertical speed indicator) which shows visually (and often audibly) the presence of lift and sink. Having located a thermal, a glider pilot will circle within the area of rising air to gain height. In the case of a cloud street thermals can line up with the wind creating rows of thermals and sinking air. A pilot can use a cloud street to fly long straight-line distances by remaining in the row of rising air.

Ridge lift Ridge lift occurs when the wind meets a mountain, cliff or hill. The air is deflected up the windward face of the mountain, causing lift. Gliders can climb in this rising air by flying along the feature. Another name for flying with ridge lift is slope soaring.

Mountain waves The third main type of lift used by glider pilots is the lee waves that occur near mountains. The obstruction to the airflow can generate standing waves with alternating areas of lift and sink. The top of each wave peak is often marked by lenticular cloud formations. Convergence Another form of lift results from the convergence of air masses, as with a sea-breeze front. More exotic forms of lift are the polar vortexes which the Perlan Project hopes to use to soar to great altitudes.[12] A rare phenomenon known as Morning Glory has also been used by glider pilots in Australia.[13]

[edit]Performance

Hang gliding at Hyner, Pennsylvania. With each generation of materials and with the improvements in aerodynamics, the performance of hang gliders has increased. One measure of performance is the glide ratio. For example, a ratio of 12:1 means that in smooth air a glider can travel forward 12 meters while only losing 1 meter of altitude. Some performance figures as of 2006: • Topless gliders (no kingpost): glide ratio ~17:1, speed range ~30 to >145 km/h, best glide at ~45 to 60 km/h • Rigid wings: glide ratio ~20:1, speed range ~ 35 to > 130 km/h, best glide at ~50 to 60 km/h. Ballast The extra weight provided by ballast is advantageous if the lift is likely to be strong. Although heavier gliders have a slight disadvantage when climbing in rising air, they achieve a higher speed at any given glide angle. This is an advantage in strong conditions when the gliders spend only little time climbing in thermals. [edit]Stability and equilibrium

High performance flexible wing hang glider. 2006 Because hang gliders are most often used for recreational flying, a premium is placed on gentle behavior especially at the stall and natural pitch stability. The wing loading must be very low in order to allow the pilot to run fast enough to get above stall speed. Unlike a traditional aircraft with an extended fuselage andempennage for maintaining stability, hang gliders rely on the natural stability of their flexible wings to return to equilibrium in yaw and pitch. Roll stability is generally set to be near neutral. In calm air, a properly designed wing will maintain balanced trimmed flight with little pilot input. The flex wing pilot is suspended beneath the wing by a strap attached to his harness. The pilot lies prone (sometimes supine) within a large, triangular, metal control frame. Controlled flight is achieved by the pilot pushing and pulling on this control frame thus shifting his weight fore or aft, and right or left in coordinated maneuvers. Roll Most flexible wings are set up with near neutral roll due to sideslip (anhedral effect). In the roll axis, the pilot shifts his body mass using the wing control bar, applying a rolling moment directly to the wing. The flexible wing is built to flex differentially across the span in response to the pilot applied roll moment. For example, if the pilot shifts his weight to the right, the right wing trailing edge flexes up more than the left, allowing the right wing to drop and slow down. Yaw The yaw axis is stabilized through the sweep back of the wings. The swept planform, when yawed out of the relative wind, creates more lift on the advancing wing and also more drag, stabilizing the wing in yaw. If one wing advances ahead of the other, it presents more area to the wind and causes more drag on that side. This causes the advancing wing to go slower and to fall back. The wing is at equilibrium when the aircraft is traveling straight and both wings present the same amount of area to the wind. Pitch The pitch control response is direct and very efficient. It is partially stabilized by the sweep of the wings. The wing center of gravity is close to the hang point and, at the trim speed, the wing will fly "hands off" and return to trim after being disturbed. The weight-shift control system only works when the wing is positively loaded (right side up). Positive pitching devices such as reflex lines or washout rods are employed to maintain a minimum safe amount of washout when the wing is unloaded or even negatively loaded (upside down). Flying faster than trim speed is accomplished by moving the pilot's weight forward in the control frame; flying slower by shifting the pilot's weight aft (pushing out).

Furthermore, the fact that the wing is designed to bend and flex, provides favorable dynamics analogous to a spring suspension. This allows the wing to be less susceptible to turbulence and provides a gentler flying experience than a similarly sized rigid-winged aircraft.

[edit]Instruments To maximize a pilot's understanding of how the hang glider is flying, most pilots carry instruments. The most basic being a variometer and altimeter—often combined. Some more advanced pilots also carry airspeed indicators and radios. When flying in competition or cross country, pilots often also carry maps and/or GPS units. Hang gliders do not have instrument panels as such, so all the instruments are mounted to the control frame of the glider or occasionally based on one's watch.

[edit]Variometer Main article: Variometer Vario-altimeter (circa 1998) Gliding pilots are able to sense the acceleration forces when they first hit a thermal, but have difficulty gauging constant motion. Thus it is difficult to detect the difference between constantly rising air and constantly sinking air. A variometer is a very sensitive vertical speed indicator. The variometer indicates climb rate or sink rate with audio signals (beeps) and/or a visual display. These units are generally electronic, vary in sophistication, and often include an altimeter and an airspeed indicator. More advanced units often incorporate a barograph for recording flight data and/or a built-in GPS. The main purpose of a variometer is in helping a pilot find and stay in the ‘core’ of a thermal to maximize height gain, and conversely indicating when he or she is in sinking air and needs to find rising air. Variometers are sometimes capable of electronic calculations to indicate the optimal speed to fly for given conditions. The MacCready theory answers the question on how fast a pilot should cruise between thermals, given the average lift the pilot expects in the next thermal climb and the amount of lift or sink he encounters in cruise mode.[14] Some electronic variometers make the calculations automatically, allowing for factors such as the glider's theoretical performance (glide ratio), altitude, hook in weight, and wind direction. [edit]Radio

Aircraft radio Pilots use radio for training purposes, and for communicating with other pilots in the air – particularly when traveling together on cross-country flights. One type of radios used are PTT (push-to-talk) transceivers, operating in or around the FM VHF 2-meter band (144 MHz–148 MHz). Usually a microphone is incorporated in the helmet, and the PTT switch is either fixed to the outside of the helmet, or strapped to a finger. Operating a 2-meter band radio without an appropriate Amateur Radio license is illegal in most countries that have regulated airwaves (such as the United States). As aircraft operating in airspace occupied by other aircraft, hang glider pilots also use the appropriate type of radio i.e. the aircraft transceiver. It can, of course, be fitted with a PTT switch to a finger and speakers inside the helmet. The use of aircraft transceivers is subject to regulations specific to the use in the air such as frequencies restrictions but has several advantages over FM (i.e. frequency modulated) Amateur Radios. One is the great range it has (without repeaters) because of its amplitude modulation (i.e. AM). Two is the ability to contact, inform and be informed directly by other aircraft pilots of their intentions thereby improving collision avoidance and increasing safety. Three is to allow greater liberty regarding distance flights in regulated , in which the aircraft radio is normally a legal requirement. Four is the universal emergency frequency monitored by all other users and satellites and used in case of emergency or impending emergency.

[edit]GPS

GPS (global positioning system) is a necessary accessory when flying competitions, where it has to be demonstrated that way-points have been correctly passed. It can also be interesting to view a GPS track of a flight when back on the ground, to analyze flying technique. Computer software is available which allows various analyses of GPS tracks. Other uses include being able to determine drift due to the prevailing wind when flying at altitude, providing position information to allow restricted airspace to be avoided, and identifying one’s location for retrieval teams after landing-out in unfamiliar territory.[citation needed] More recently, the use of GPS data, linked to a computer, has enabled pilots to share 3D tracks of their flights on Google Earth. This fascinating insight allows comparisons between competing pilots to be made in a detailed post-flight analysis.[citation needed]

[edit]Records Records are sanctioned by the FAI. The world record(s) (as of 2005) for "free distance" is held by Manfred Ruhmer with 700.6 km (435.3 mi) in 2001 and Michael Barber flew a distance of 704 km (437 mi) on June 19, 2002 in Zapata Texas.[15] Other records include: Out-and-Return distance - 332.5 km (206.6 mi), July 5, 2007 by George Stebbins, starting and ending just South of Lone Pine, California. Largest triangle - 357.12 km (221.90 mi), December 16, 2000 by Tomáš Suchánek a Czech HG and sailplane pilot, starting and ending from Riverside, Australia.[citation needed]

[edit]Competition Competitions started with "flying as long as possible" and spot landings. With increasing performance, cross-country flying replaced them. Usually two to four waypoints have to be passed with a landing at a goal. In the late 1990s low- power GPS units were introduced and have completely replaced photographs of the goal. Every two years there is a world championship. The Rigid and Women's World Championship in 2006 was hosted by Quest Air in Florida. Big Spring, Texas hosted the 2007 World Championship. Hang gliding is also one of the competition categories in organized by Fédération Aéronautique Internationale (World Federation - FAI), which maintains a chronology of the FAI World Hang Gliding Championships.[16]

[edit]Aerobatics Hang gliders are not certified for aerobatic flight. Pilots perform aerobatics at their own risk. There are three basic maneuvers in a hang glider, not counting a loop, which is actually a climbover with the same entry and exit heading. The following descriptions are excerpts from a nationally recognized rules book. 3.1 Official Maneuvers A figure with a bank angle of more than 90° is a maneuver. 3.1.1 Loop A loop is defined as a maneuver that starts in a wings level dive, climbs, without any rolling, to the apex where the glider is upside down, wings level (heading back where it came from), and then returning to the start attitude and heading, again without rolling, having completed an approximately circular path in the vertical plane. 3.1.2 Spin A spin is scored from the moment one wing stalls and the glider rotates noticeably into the spin. The entry heading is noted at this point. The glider must remain in the spin for at least 1/2 of a revolution to score any versatility spin points. 3.1.3 Rollover A Rollover is a maneuver where the apex heading is less than 90° left or right of the entry heading. 3.1.4 Climb over A Climb over is a maneuver where the apex heading is greater than 90° left or right of the entry heading.

[edit]Classes

Modern 'flexible wing' hang glider. For competitive purposes, there are three classes of hang glider: • Class 1 The flexible wing hang glider, having flight controlled by a wing whose shape changes by virtue of the shifted weight of the pilot. This is not aparaglider. • Class 5 The rigid wing hang glider, having flight controlled by spoilers, typically on top of the wing. In both flexible and rigid wings the pilot hangs below the wing without any additional fairing. • Class 2 (designated by the FAI as Sub-Class O-2) where the pilot is integrated into the wing by means of a fairing. These offer the best performance and are the most expensive. In addition to typical launch configurations, a hang glider may be so constructed for alternative launching modes other than being foot launched; one practical avenue for this is for people who physically cannot foot-launch. [17]

[edit]Comparison of gliders, hang gliders and paragliders There can be confusion between gliders, hang gliders, and paragliders. Paragliders and hang gliders are both foot-launched glider aircraft and in both cases the pilot is suspended ("hangs") below the lift surface, but "hang glider" is the default term for those where the airframe contains rigid structures. The primary structure of paragliders is supple, consisting mainly of woven material. [18] The main differences between the types are:[citation needed] Paragliders Hang gliders Gliders/Sailplanes Undercarriage Pilot's legs used for take- Pilot's legs used for Aircraft takes off and lands using off and landing take-off and landing a wheeled undercarriage or skids Wing structure entirely flexible, with generally flexible rigid surface to wings that totally shape maintained purely but supported on a encases structure by the pressure of air rigid frame which flowing into and over the determines its wing in flight and the shape, but note that tension of the lines rigid wing hang gliders also exist Pilot position sitting supine in a seated usually lying prone sitting in a seat with a harness harness. in a cocoon-like surrounded by a crash-resistant harness suspended structure. from the wing. Seated, and 'supine' are also possible. Speed range slower – typically 25 to easier to launch and even faster - maximum speed up (stall speed – 60km/h for recreational fly in stronger to about 280 km/h (170 mph); max speed) gliders (over 40km/h conditions with stall speed typically 65 km/h requires use of speed bar) better wind (40mph). Able to fly in windier [19] hence easier to launch penetration, and can turbulent conditions and can and fly in light winds, outrun bad weather, outrun bad weather. Exceptional least wind penetration, weight shift pitch penetration into the wind. Semi- pitch variation can be control[citation or fully aerobatic. achieved with the controls. needed] Maximum glide about 10, relatively poor about 17 for Open class sailplanes typically ratio glide performance makes flexible wings, around 60:1 but in more common long-distances more though up to 20 for 15-18 meter span aircraft, glide difficult. The current rigid wings. ratios are between 38:1 and world record is just above [citation needed] 52:1. [21], high glide 500 km (310 miles)[20] performance enabling long distances, 3,000 km (1,800+ mile record)[22] Turn radius tighter turn radius, somewhat larger even greater turn radius but still allowing circling in the turn radius, not able to circle tightly in thermals rapidly rising center of allowing such a thermals high rate of climb in thermals Landing smaller space needed to longer approach & can land in less than 200 metres land, offering more landing area and can often reach another landing options from required, but can airfield.[citation cross-country flights. Also reach more landing needed] Specialised trailer easier to carry back to the areas due superior needed to retrieve by road nearest road glide range Learning simplest and quickest to teaching is done in a two seat learn glider with dual controls Convenience packs smaller (easier to more awkward to trailers are typically 10 m (30 ft) transport and store); transport & store; long. Rigging & de-rigging takes lighter (can be easily longer to rig and about 20 minutes carried considerable de-rig; transported distances); quicker to rig on the roof of a car & de-rig; transported in the trunk of a car Cost cost new €2000 up[23], cost of new gliders very high but cheapest but shortest lasting (around 500 hours long lasting (several decades), so flying depending on active second hand market treatment) but active typically from €2000 to second hand market[24] €145,000[25] . Often shared ownership[citation needed]

Tightrope walking

From Wikipedia, the free encyclopedia

(Redirected from High wire)

"Tightrope" redirects here. For other uses, see Tightrope (disambiguation). This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2007)

The feet of a tightrope walker. Tightrope walking (or funambulism) is the art of walking along a thin wire or rope, usually at a great height. One or more artists performs in front of an audience (a common act in circuses) or as a publicity stunt (often attempting to set location-specific distance or height records). Tightrope walkers sometimes use balancing poles and may perform the feat without a safety net for effect.

Contents [hide] • 1 Styles of tightrop e acts • 2 Biom echanic s • 3 Famo us tightrop e artists • 4 Refer ences • 5 Exter nal links

[edit]Styles of tightrope acts • Tightwire is the art of maintaining balance while walking along a tensioned wire between two points. It can be done either using a balancing tool (umbrella, fan, balance pole, etc.) or "freehand", using only one's body to maintain balance. Typically, tightwire performances will fall into one of two distinct types of acts: dance/movement or object manipulation. It is common for tightwire artists to include a variety of props in their acts, such as clubs or rings, hats or canes in order to help them maintain their balance. Other artists will take props onto the wire in order to enhance the entertainment value. These often include juggling clubs, spinning plates, wheelbarrows with passengers, ladders, pets and children. • Highwire is the same as tight wire but at much greater height. Although there is no official height when tight wire becomes high wire, generally a wire over twenty feet high will be regarded as a high wire act. Traditionally, the difference is in style of performance.

Slackwire artist catching juggling torches • Slackwire is when the tension on the wire is only provided by the load, i.e. the performer and props. The difference is that to balance on a tight wire the performer must keep his centre of mass above his feet, while on a slack wire he moves the wire with his balance to under his centre of mass.[clarification needed] • Skywalk is a form somewhat akin to highwire, but generally defined by its length and height, often taking place outdoors at great heights, often between skyscrapers, gorges, mountains or other natural and man-made landscapes. • is a balance sport which utilizes nylon webbing stretched tight between two anchor points. Slacklining is distinct from tightrope walking in that the line is not held rigidly taut; it is instead dynamic, stretching and bouncing like a long and narrow trampoline. • Freestyle slacklining (a.k.a. “rodeo slacklining") is the art and practice of cultivating balance on a piece of rope or webbing draped slack between two anchor points, typically about 15 to 30 feet (9.1 m) long and a couple feet off the ground in the centre. This type of slackline provides a wide array of opportunities for both swinging and static maneuvers. A freestyle slackline has no tension in it, while both traditional slacklines and tightropes are tensioned. The slackness in the rope or webbing allows it to swing at large amplitudes and adds a different dynamic to the art. • Funambule (French) • Jultagi (Korean)

[edit]Biomechanics Acrobats maintain their balance by positioning their center of mass directly over their base of support, i.e., shifting most of their weight over their legs, arms or whatever part of their body they are using to hold them up. When they are on the ground with their feet side by side, the base of support is wide in the lateral direction but narrow in the sagittal (back-to-front) direction. In the case of highwire-walkers, their feet are parallel with each other, one foot positioned in front of the other while on the wire. Therefore, a tightwire walker's sway is side to side, their lateral support having been drastically reduced. In both cases, whether side by side or parallel, the ankle is the pivot point. A wire-walker may use a pole for balance or may stretch out his or her arms perpendicular to her trunk in the manner of a pole. This technique provides several advantages. It distributes mass away from the pivot point and moves the center of mass out. This reduces angular acceleration because their center of mass is now swinging through a longer arc. It takes longer to sweep out the same angle because the center of mass has a longer distance to go. The result is less tipping. In addition the performer can also correct sway by rotating the pole sideways. This will create an equal and opposite torque on the body. Sometimes the pole is weighted and has a dip at the ends. This provides additional stability by lowering the center of mass. Tightwire-walkers typically perform in very thin and flexible, leather-soled slippers with a full length suede or leather sole to protect the feet from abrasions and bruises while still allowing the foot to curve around the wire. Though very infrequent in performance, amateur, hobbyist, or inexperienced funambulists will often walk barefoot so that the wire can be grasped between the big and second toe. This is more often done when using a rope, as the softer and silkier fibers are less taxing on the bare foot than the harder and more abrasive braided wire.

Wingsuit flying From Wikipedia, the free encyclopedia

(Redirected from Sky flying)

Wingsuits in flight is the sport of flying the human body through the air using a special jumpsuit, called a wingsuit, which adds surface area to the human body to enable a significant increase in lift. Modern wingsuit designs create the surface area with fabric between the legs and under the arms. A wingsuit may be referred to as a birdman suit or flying squirrel suit. A wingsuit flight ends with a parachute opening, so a wingsuit can be flown from any point that provides sufficient altitude to glide through the air, such as skydiving aircraft or BASE jumping exit points, and to allow a parachute to deploy. The wingsuit flier wears parachute equipment designed for skydiving or BASE jumping. The flier deploys the parachute at a planned altitude and unzips the arm wings, if necessary, so they can reach up to the control toggles and fly to a normal parachute landing. Contents [hide] • 1 Histor y • 2 Com mercial area • 3 Non- technica l mechan ics • 4 Furth er develop ments • 4 . 1

W i n g p a c k • 4 . 2

W i S B A S E • 4 . 3

J e t - p o w e r e [edit]History Wings were first used in the 1930s as an attempt to increase horizontal movement. These early wingsuits were made of materials such as canvas, wood, silk, steel, and even whale bone. They were not very reliable. Some "birdmen", notably Clem Sohn and Leo Valentin, claimed to have glided for miles. The wingsuit was showcased in the 1969 movie The Gypsy Moths starring Burt Lancaster andGene Hackman. On October 31, 1997, French skydiver Patrick de Gayardon showed reporters a wingsuit that had unparalleled safety and performance. [1] [2] De Gayardon died on April 13, 1998 while testing a new modification to his parachute container in Hawaii; his death is attributed to a rigging error which was part of the new modification rather than a flaw in the suit's design. In early 1998, Tom Begic, a BASE jumper from Australia, built and flew his own wingsuit based on a photograph of Patrick de Gayardon and his ideas. The suit was developed to assist Begic in capturing freefall footage of BASE jumpers while jumping the high cliffs of Europe. In early 1999, Begic stopped development of his suit when he met Robert Pečnik and learned of plans for the creation of a wingsuit manufacturing company. Phoenix Fly was started in the mid 2000s.

[edit]Commercial area In 1999, Jari Kuosma of Finland and Robert Pečnik of Croatia teamed up to create a wingsuit that was safe and accessible for all skydivers. Kuosma established Bird-Man International Ltd. the same year. BirdMan's Classic, designed by Pečnik, was the first wingsuit offered to the general public. BirdMan was the first manufacturer to advocate the safe use of wingsuits by creating an instructor program. Created by Kuosma, the instructor program's aim was to remove the stigma that wingsuits were dangerous and to provide wingsuit beginners (generally, skydivers with a minimum of 200 jumps) with a way to safely enjoy what was once considered the most dangerous feat in the skydiving world. With the help of Birdman instructors Scott Campos, Chuck Blue and Kim Griffin, a standardized program of instruction was developed that prepared instructors.[3] Phoenix-Fly, Fly Your Body, and Nitro Rigging have also instituted an instructor training program.

[edit]Non-technical mechanics The wingsuit flier enters freefall wearing both a wingsuit and parachute equipment. Exiting an aircraft in a wingsuit requires skilled techniques that differ depending on the location and size of the aircraft door. These techniques include the orientation relative to the aircraft and the airflow while exiting, and the way in which the flier will spread his legs and arms at the proper time so as not to hit the aircraft or become unstable in the relative wind. The wingsuit will immediately start to fly upon exiting the aircraft in the relative wind generated by the forward speed of the aircraft. Exiting from a BASE jumping site, such as a cliff, or exiting from a helicopter, a paraglide or a hot air balloon, is fundamentally different from exiting a moving aircraft, as the initial wind speed upon exit is absent. In these situations, a vertical drop using the forces of gravity to accelerate is required to generate the airspeed that the wingsuit can then convert to lift. At a planned altitude above the ground in which a skydiver or BASE jumper would typically deploy his parachute, a wingsuit flier will deploy his parachute. The parachute will be flown to a controlled landing at the desired landing spot using typical skydiving or BASE jumping techniques. A wingsuit flier manipulates the shape of his body to create the desired amount of lift and drag although most wingsuits have a 2.5 to 1 ratio. This means that for every foot dropped, two and a half feet are gained moving forward. With body shape manipulation and by choosing the design characteristics of the wingsuit, a flier can alter both his forward speed and fall rate. The pilot manipulates these flight characteristics by changing the shape of his torso, arching or bending at the shoulders, hips, and knees, and by changing the angle of attack in which the wingsuit flies in the relative wind, and by the amount of tension applied to the fabric wings of the suit. The absence of a vertical stabilizing surface results in little damping around the yaw axis, so poor flying technique can result in a spin that requires active effort on the part of the skydiver to stop. Wingsuit fliers can measure their performance relative to their goals with the use of freefall computers that will indicate the amount of time they were in flight, the altitude they deployed their parachute, and the altitude they entered freefall. The fall rate speed can be calculated from this data and compared to previous flights. GPS receivers can also be used to plot and record the flight path of the suit, and when analyzed can indicate the amount of distance flown during the flight. BASE jumpers can use landmarks on exit points, along with recorded video of their flight by ground crews, to determine their performance relative to previous flights and the flights of other BASE jumpers at the same site. A typical skydiver's terminal velocity in belly to earth orientation ranges from 110 to 140 mph (180–225 km/h). A wingsuit can reduce these speeds dramatically. An instantaneous velocity of -25 mph (-40 km/h) has been recorded.[4] The tri-wing wingsuit has three individual ram-air wings attached under the arms and between the legs. The mono-wing wingsuit design incorporates the whole suit into one large wing.

[edit]Further developments

[edit]Wingpack

a jet-powered wingpack Another variation on which studies are being focused is the so- called wingpack, which consists of a strap-on rigid wing in carbon fibre.[5] It is a mix between a hang-gliderand a wingsuit. The wingpack can reach a glide ratio of 6 and permits transportation of oxygen bottles and other material.[6] On July 31, 2003 an Austrian, , jumping from 29,360 ft (9 km), successfully crossed the English Channel in 14 minutes using a wingpack, having covered over 35 km (21.8 mi).[7] In 2006, the German enterprise ESG introduced Gryphon, a wingpack specifically destined for the secret incursions of the special forces.[8]

[edit]WiSBASE Since 2003[9] many BASE jumpers have started using wingsuits, giving birth to WiSBASE, regarded by some as the future of BASE jumping and the best course of development of wingsuit flying. Among the main places where the WiSBASE practice in Europe is reported Kjerag and Trollstigen in Norway, Lauterbrunnen in Switzerland, and Monte Brento in Italy, with the landing field near Dro. One technique, risky and spectacular, is proximity flying, which is flying close to the faces and ridges of mountains. On July 1, 2011, Jeb Corliss became the first man to fly through a waterfall wearing a wingsuit Apache.[10] [edit]Jet-powered wingsuits

While still very experimental, powered wingsuits, often using small jet engines strapped to the feet[11] or a wingpack set-up, allow for even greater horizontal travel and even ascent. On 25 October 2005 in Lahti in Finland, Visa Parviainen jumped from a hot air balloon in a wingsuit with two small turbojet jet engines attached to his feet. The turbojets provided approximately 16 kgf (160 N, 35 lbf) of thrust each and ran on kerosene (JET A-1) fuel. Parviainen apparently achieved approximately 30 seconds of horizontal flight with no noticeable loss of altitude.[11] On August 2011 Visa performed flight in Finland, jumped from a hot air balloon, started his engines and could gain hundreds meters of altitude with the power of his turbojets. Christian Stadler (Birdman Chief Instructor) from Germany organized the first international wingsuit competition with prize money SkyJester's Wings over Marl in 2005. His world wide first achievement the VegaV3 wingsuit system uses an electronic adjustable hydrogen peroxide rocket[12] This rocket provided 100 kgf of thrust, and produces no flames or poisonous fumes. His first successful powered wingsuit jump was in 2007 with more than 160 mph horizontal speed.[13] Using a powered wingpack, Yves Rossy became the first person to obtain the maneuverability of an aircraft while steering solely with body movement; his experimental wingpack, however, is not commercially viable because of the fuel the wing uses, and the materials required in construction are prohibitive in cost. Nonetheless, his eight-minute flight over the Swiss Alps made headlines around the world, and so far, his "jet-wingpack" remains the only one capable of sustained flight.

[edit]Training Flying a wingsuit adds considerable complexity to a skydive. The United States Parachute Association (USPA) requires in the Skydivers Information Manual that any jumper flying a wingsuit for the first time have a minimum of 200 freefall skydives, made within the past 18 months, and receive one-on-one instruction from an experienced wing suit jumper, or 500 jumps experience to go without an instructor.[14] Requirements in other nations are similar. Wingsuit manufacturers offer training courses and certify instructors. [edit]Records On July 24, 2008, Australian couple Heather Swan and Glenn Singleman jumped from 37,000 ft (11.27 km) over central Australia setting a world record for highest wingsuit jump. [15] [16] Fédération Aéronautique Internationale has not established judging criteria for official world record wingsuit formations. However, several national organizations have established record categories and have established criteria for judging whether or not a wingsuit formation is complete. The largest wingsuit formation officially recognized as meeting the criteria for a national record consisted of 68 jumpers in an arrowhead formation which set a US National Record at Lake Elsinore, California, on 12 November 2009.[17] The largest unofficial record was a B-2 formation involving 71 jumpers at Lake Elsinore, California, in November 2008.[18] The longest verified WiSBASE jump is 5.8 km (3.6 mi) by Dean Potter [19] in August, 2009. Potter jumped from Eiger and had spent 2 minutes and 50 seconds in flight, covering 7,900 ft (2.4 km) of altitude. On May 28, 2011, Japanese wingsuit pilot Shin Ito set world records for the longest wingsuit flight of 23.1 km (14.4 mi) and a flight time of 5 minutes and 22 seconds, jumped from 9,800 metres (32,000 ft)[20] and the fastest speed reached in a wingsuit of 363 km/h (226 mph).[21]