Skydiving is the recreational and sports form of parachuting, in contrast to military and pararescue operations. It is practiced all around the world, the most important contributing countries being United States, United Kingdom and Germany.
While the parachute had already been invented by Leonardo da Vinci, skydiving as sports and recreational pastime began after the World War II. Many ex-servicemen, who had been paratroopers and participated in paradrops operations, bought themselves surplus Army equipment and formed skydiving clubs, using WWII surplus transport airplanes. Recreational skydiving quickly caught on all countries which had arranged paradrop operations in WWII and soon spred all around the world.
Skydiving is considered as a form of leisure aviation, and the same general flying regulations apply to it as on any aviation.
Skydiving is mostly practiced on clubs, while there are commercial service providers as well. To be able to practice skydiving, one has to go through training and complete the course, student jumps and final examination and prove he or she can pack his/her own parachute safely. A novice skydiver who has successfully passed the course and examination will get an 'A' licence, allowing him or her to jump independently but with certain restrictions.
First timers will often be introduced in the sports on tandem skydiving. The novice skydiver is literally strapped on the belly of the jumpmaster (an experienced skydiver with at least 500 freefalls and three years to the sport) on buckles and harnesses, and they jump together, falling together through the sky. The jumpmaster then deploys the parachute at given altitude, giving the novice an opportunity to steer the parachute in the air during the glide. The jumpmaster performs the landing. Tandem skydiving also provides those people who otherwise would not be able to jump (people with chronical diseases, disabilities or health issues) a chance to experience skydiving.
There are two methods to learn skydiving: instructor assisted deployment (IAD) and accelerated free fall (AFF). The instructor assisted deployment is based on the oldest method, static line deployment, and on IAD, the student jumps alone, with the instructor, who stays in the plane, opening his or her parachute remotely with a static line. It is less expensive but requires more jumps. On the accelerated free fall method, the student jumps together with instructors, who then give him or her various practises during the free fall, and the student deploys his or her parachute by him/herself at given altitude. It is more expensive but the learning curve is much steeper, and less jumps are needed to learn the basics and the manouevres mid-air. Besides the actual jumps themselves, the student will also learn how to pack his/her own parachute and how to check his/her gear (called rig in skydiving lingo). Modern sports video cameras have brought another dimension on learning the skydiving as the jumps may be filmed and inspected together with the instructor afterwards. The usual amount of student jumps needed for A licence are 25 (absolute minimum on AFF) to 35 (usually).
The gear needed are parachute, altimeter, crash helmet, jumpsuit, gloves and jump shoes. Many skydivers prefer jogging shoes. The parachutes used on skydiving are almost exclusively the square "wing" ram-air parachutes, which are fully controllable and steerable, and much safer than the older Army style "bell" parachutes. The altimeter has either Metric or feet reading, and is based on a barometer. It is adjusted at the airport to zero.
The parachute rig contains, not just one, but two parachutes: the main and the reserve. The main parachute is the one which is normally used, but should problems arise, the skydiver will perform cut-away, jettisoning the main, and deploy the reserve parachute. In many countries automatic activation devices (AAD) are required. They will deploy the reserve parachute automatically if the main has not opened until a given altitude, usually 300 m or 1000 ft. The rig consists of the backpack and harness, and the parachute itself. The parachute canopy is connected to the harness by lines, which connect to four straps called risers which are on turn connected to the harness by three-ring release system. The canopy consists of two layers of fabric which are sewn together so that they form nine pairs of tunnels. When the canopy deploys, the tunnels are filled with air and the canopy gets a wing profile form, enabling it to glide instead of just descending vertically. When the parachute is opened, a rectangular piece of fabric called slider slides down on the lines, softening the opening.
A skydiving jump consists of five parts: exit, free fall, deployment, glide and landing.
Exit means jumping off a perfectly good and functional airplane mid-air into the wild blue yonder. The usual exit altitude is 4000 m (in those countries who use Metric system) or 13,000 ft (in UK and dominions) or 12,500 ft (USA). When exiting, the skydiver takes the stable position and prepares for the free fall. Learning a good exit and finding the stable position is the most important thing on first student jumps.
Free fall is falling freely through the air by means on gravity. The drag of air will stablize the velocity of the skydiver to 50-55 m/s after the first ten seconds. This is the part of the jump usually considered most fun and during which the skydivers practise various manouevres or perform the formation skydiving movements and formations.
Deployment is opening the parachute. Unlike shown on the movies and TV series, modern skydiving rigs do not have ripcords. The metal handle on the left side strap is actually the reserve parachute deployment handle. The main parachute is deployed by pulling out a small round auxiliary parachute called drogue chute by its handle or knob, and throwing it into the slipstream. The handle is usually located at the bottom of the backpack. That is to allow the main to be deployed on stable position. The usual deployment altitude is from 1600 to 1000 m (5200 to 3000 ft). The drogue chute then opens the backpack, pulls out the pod of the main parachute and the lines out, and the main out of the pod. Once in the air, the main parachute will develop automatically. Should things go wrong, every student skydiver is taught on how to do the reserve chute deployment.
Glide is flying by the means of parachute. Modern wing chutes are controlled by the means of brakes and control loops, and they have a glide ratio of 1:2 to 1:3. Now it is time to relax and enjoy the view below and prepare for the landing. Be careful not to collide with other skydivers or anything else that flies, though!
Landing is bringing yourself and your parachute to ground on controlled means. The landing pattern is exactly the same as in any other form of aviation, and the students usually learn very quickly on how to land on given spot with precision. The landing pattern consists of tailwind leg, base leg and final approach (headwind). When at 2 to 3 m altitude (6 to 10 ft), the skydiver performs a controlled full braking called flare, extinguishing his/her forward speed, allowing him/her to land vertically on the ground. Beginners are taught always to perform the parachute landing fall for safe landing.
A place where skydiving is practised is called a drop zone, often abbreviated DZ or Delta Zulu. A drop zone usually consists of airstrip, airfield apron, landing area, club house, parachute packing facility and social facilities, such as bunkhouse, restaurant etc. Drop zone regulars are skydivers who practise the hobby on daily or weekly basis, and often either work there or are officials of the club.
Airplanes used on skydiving are usually light cargo planes with good ascending properties, such as de Havilland Twin Otter, Short Skyvan, Antonov An-2, Cessna Caravan, Pilatus Turbo Porter etc. Sometimes military planes, such as Antonov An-24, Fokker Friendship or Douglas C-47 are used. Also small private planes, such as Cessna 172 are sometimes used. The airplane must be approved on skydiving by aviation authorities, and must have floor bolted safety belts and closeable jump door.
The minimum amount of jumps required in US for 'A' licence is 25. The minimum for 'B' licence is 50 + canopy handling examination. The minimum for 'C' licence is 200 and 'D' licence 500. The amount of jumps vary by country; in UK, 1000 jumps are needed for 'D' licence.
There are various styles and disciplines on skydiving:
Accuracy: the skydivers attempt to land as accurately on a given spot as possible.
Angle Flying: The technique consists of flying diagonally with a determinate relation between angle and trajectory speed of the body, to obtain an air stream that allows for control of flight. The aim is to fly in formation at the same level and angle, and to be able to perform different aerial games, such as freestyle, three-dimensional flight formation with grip, or acrobatic freeflying.
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.
Formation skydiving: Formation Skydiving (FS) was born in California, USA during the 1960s. The first documented skydiving formation occurred over Arvin, California in March 1964 when Mitch Poteet, Don Henderson, Andy Keech and Lou Paproski successfully formed a 4-man star formation, photographed by Bob Buquor. This discipline was formerly referred to in the skydiving community as Relative Work. In formation skydiing, the skydivers attempt to form a pre-planned formation during the free fall and work in choreography.
Freeflying: Freeflying is an expansion of skydiving which includes the traditional belly-to-earth positions, but extends into vertical flight where the flyer is in an upright position (falling feet first) or in an inverted position (falling head first). These positions increase freefall speeds and make new types of formations and routines possible.
Skysurfing: Sky surfing is a type of skydiving in which the skydiver wears a board attached to his or her feet and performs surfing-style aerobatics during freefall. The boards used are generally smaller than actual surfboards, and look more like snowboards or large skateboards. The attachment to the feet is normally made removable, so that if the skydiver loses control or has difficulty opening their parachute, the board can be jettisoned.
Style: Style can be considered as sprint of parachuting. This individual discipline is played in free fall. The idea is to take maximum speed and complete a pre-designated series of manoeuvres as fast and cleanly as possible (speed can exceed 400 km/h / 250 mph). Performance is timed (from the start of the manoeuvre until its completion) and then judged in public at the end of the jump. Competition includes 4 qualifying rounds and a final for the top 8. Competitors jump from a height of 2200 m to 2500 m.
Swoop and chug: A tradition at many drop zones is the swoop and chug. As parachutists land from the last load of the day, other skydivers often hand the landing skydivers a beer that is customarily chugged in the landing area. This is sometimes timed as a friendly competition, but is usually an informal, untimed, kick-off for the night's festivities.
Tracking: Tracking is where skydivers take a body position to achieve a high forward speed, allowing them to cover a great distance over the ground. Tracking is also used at the end of group jumps to achieve separation from other jumpers before parachute deployment. The tracking position involves sweeping the arms out to the side of the body and straightening the legs with the toes pointed.
Wingsuit flying: Wingsuit flying is the sport of flying through the air using a wingsuit, which adds surface area to the human body to enable a significant increase in lift. The modern wingsuit, first developed in the late 1990s, creates a surface area with fabric between the legs and under the arms. A wingsuit flight normally ends by deploying a parachute, and so a wingsuit can be safely flown from any point that provides sufficient altitude for flight and parachute deploymentnormally a skydiving drop aircraft.
Contrary to its popular image, skydiving is actually fairly safe hobby. Due to modern equipment, training and licence requirements, safety regulations and skydiving culture which stresses safety, fatalities are nowadays very rare, occurring in 8 in 1,000,000 jumps. Usual causes for fatalities are human errors, such as mid-air collisions or attempting an unsafe maneuver on low altitude or on landing pattern. One jump in 1000 will statistically end on cut-away and use of reserve chute, mostly due to packaging error. Gear failures are extremely rare.
Jumping off a fixed platform, such as bridge, building or cliff, instead of an airplane is called BASE jumping (Buildings, Aerials, Spans, Earth). It is considered as an insanely dangerous activity, as it leaves the jumper far less marigin for errors and parachute opening than conventional skydiving. (It is estimated 1 in 2,500 BASE jumps will end in death and 1 in 200 in serious injury.) BASE jumping is illegal in many countries, and discouraged in others, as it often involves in trespassing and illegal entry of buildings, chimneys or ancilliary installations.