Parachuting
Parachuting, including also skydiving, is a method of transiting from a high point in the atmosphere to the surface of Earth with the aid of gravity, involving the control of speed during the descent using a parachute or parachutes. For human skydiving, it may involve a phase of more or less free-falling (the skydiving segment) which is a period when the parachute has not yet been deployed and the body gradually accelerates to terminal velocity. For cargo parachuting, the parachute descent may begin immediately, such as a parachute-airdrop in the lower atmosphere of Earth, or be significantly delayed, such as in a planetary atmosphere where an object is descending "under parachute" following atmospheric entry from space, and may begin only after the hypersonic entry phase and initial deceleration that occurs due to friction with the thin upper atmosphere.
The first parachute jump in history was made by André-Jacques Garnerin, the inventor of the parachute, on 22 October 1797. Garnerin tested his contraption by leaping from a hydrogen balloon 3,200 feet (980 m) above Paris. Garnerin's parachute bore little resemblance to today's parachutes, however, as it was not packed into any sort of container and did not feature a ripcord.[1] The first intentional free-fall jump with a ripcord-operated deployment was not made until over a century later by Leslie Irvin in 1919.[2] While Georgia Broadwick made an earlier free-fall in 1914 when her static line became entangled with her jump aircraft's tail assembly, her free-fall descent was not planned. Broadwick cut her static line and deployed her parachute manually, only as a means of freeing herself from the aircraft to which she had become entangled.[3] The military developed parachuting as a way to save aircrew from emergencies aboard balloons[4] and aircraft in flight, and later, as a way of delivering soldiers to the battlefield. Competitions date back to the 1930s, and it became an international sport in 1952.[how?][5] In World War II, thousands of combatants across the globe experienced exiting an aircraft and parachuting to the ground, either as a paratrooper dropped into combat or as flight crew escaping a crippled aircraft. Some servicemen discovered that it was enjoyable, and after the war ended kept jumping. The National Parachute Jumpers and Riggers was born in 1947.This group would later become the Parachute Club of America,[7] and finally its current iteration: the USPA (United States Parachute Association). Parachuting as a sport had begun to permeate the international community.[8] 1970s 'High Performance' canopy In the 1970s, sports skydiving became very popular thanks to a quick-release system of the main parachute based on the three rings or rings, designed by engineer Bill Booth, that allowed anyone to use it.[9] In 2021 a supersonic parachute was deployed to land a payload on Mars.[10]
In the U.S. during the 1970s, the sport averaged 42.5 fatalities annually. In the 1980s, the average dropped to 34.1, and in the 1990s, the average decreased to 32.3 deaths per year. Between 2000 and 2009, the average dropped to 25.8 and over the eight years after 2009, the annual average declined to 22.4 fatalities (roughly 7.5 fatalities per one million jumps). In 2017, members of one organization, the United States Parachute Association (USPA) reported 2,585 skydiving injuries sufficiently severe to require resort to a medical care facility.[12] Reserve parachute (right) in use In the US and in most of the western world, skydivers are required to wear two parachutes. The reserve parachute must be periodically inspected and repacked (whether used or not) by a certified parachute rigger (in the US, an FAA certificated parachute rigger every 180 days). Many skydivers use an automatic activation device (AAD) that opens the reserve parachute at a predetermined altitude if it detects that the skydiver is still in free fall. Depending on the country, AADs are often mandatory for new jumpers, and/or required for all jumpers regardless of their experience level.[13] Some skydivers wear a visual altimeter, and some use audible altimeters fitted to their helmets. Injuries and fatalities occurring under a fully functional parachute usually happen because the skydiver performed unsafe maneuvers or made an error in judgement while flying their canopy, typically resulting in a high-speed impact with the ground or other hazards on the ground.[14] One of the most common sources of injury is a low turn under a high-performance canopy and while swooping. Swooping is the advanced discipline of gliding at high-speed parallel to the ground during landing. A parachutist of the REME Lightning Bolts Army Parachute Display Team lands. The red smoke that gives the parachutists the wind direction during the jump is still running. Changing wind conditions are another risk factor. In conditions of strong winds and turbulence during hot days, the parachutist can be caught in downdrafts close to the ground. Shifting winds can cause a crosswind or downwind landing which have a higher potential for injury due to the wind speed adding to the landing speed. 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 causes fatalities and injuries. Approximately one in 750 deployments of a main parachute result in a malfunction.[15] Ram-air parachutes typically spin uncontrollably when malfunctioning, 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 cut away causing a reserve malfunction is a very real risk. Parachutists jumping from an Ilyushin Il-76 of the Ukraine Air Force (2014) Parachuting disciplines such as BASE jumping or those that involve equipment such as wingsuit flying and sky surfing have a higher risk factor due to the lower mobility of the jumper and the greater risk of entanglement. For this reason,[tone] these disciplines are generally practised by experienced jumpers.[citation needed] 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 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 drop zone owners require that parachutists must have attained the age of majority before engaging in the sport. The first skydive performed without a parachute was by stuntman Gary Connery on 23 May 2012 at 732 m.[16] Most common injuries[edit] Due to the hazardous nature of skydiving, precautions are taken to avoid parachuting injuries and death. For first-time solo-parachutists, this includes anywhere from 4 to 8 hours of ground instruction.[17] Since the majority of parachute injuries occur upon landing (approximately 85%),[18] the greatest emphasis within ground training is usually on the proper parachute landing fall (PLF), which seeks to orient the body so as to evenly disperse the impact through flexion of several large, insulating muscles (such as the medial gastrocnemius, tibialis anterior, rectus femoris, vastus medialis, biceps femoris, and semitendinosus),[19] as opposed to individual bones, tendons, and ligaments which break and tear more easily. The percent of injuries caused by an improper landing position. Parachutists, especially those flying smaller sport canopies, often land with dangerous amounts of kinetic energy, and for this reason, improper landings are the cause of more than 30% of all skydiving-related injuries and deaths.[18] Often, injuries sustained during parachute landing are caused when a single outstretched limb, such as a hand or foot, is extended separately from the rest of the body, causing it to sustain forces disproportional to the support structures within. This tendency is displayed in the accompanying chart, which shows the significantly higher proportion of wrist and ankle injuries among the 186 injured in a 110,000 parachute jump study. Due to the possibility of fractures (commonly occurring on the tibia and the ankle mortise), it is recommended that parachutists wear supportive footwear.[18] Supportive footwear prevents inward and outward ankle rolling, allowing the PLF to safely transfer impact energy through the true ankle joint, and dissipate it via the medial gastrocnemius and tibialis anterior muscles.