Skydiving, also known as parachuting, is when one exits an aircraft into thin air and returns to Earth with the aid of a parachute. It may or may not involve a certain amount of free-fall, a time during which the parachute has not been deployed and the body gradually accelerates to terminal velocity. Andre-Jacques Garnerin starts the history of skydiving, with making successful parachute jumps from a hot-air balloon in 1797. The military use skydiving/ parachuting as a way of delivering soldiers to the battlefield, but before that they, developed parachuting technology as a way to save aircrews from emergencies aboard balloons and aircraft in flight. As well as being in military use skydiving or parachuting is also a recreational activity and competitive sport. The person who has the aircraft, which can be one or more, to take the individuals skydiving up for a fee is known as the drop zone operator. Anywhere from 3,000 to 13,000 feet altitude, a typical jump involves individuals skydiving exiting an aircraft. From low altitudes a parachute must be deployed immediately, but at higher altitudes the individuals skydiving may free fall for a short period of time before deploying their parachute to slow speeds for a safe landing. The individual skydiving can control the parachute direction and speed by using the toggles on the end of the steering lines attached to the trailing edge of the parachute and can also aim for the landing site desired and come to a smooth landing.
Due to the forward throw (the momentum) created by the plane’s speed, the individual skydiving travels forward for a few seconds when exiting the aircraft. The resistance of the air to person skydiving body when free falling does not have the sensation of “falling” because speeds above about 50 mph provides some feeling of weight and direction. When skydiving from an aircraft at a normal exit there is little sensation of falling when at speeds which is about 90mph, however, jumping from a balloon or helicopter can create this sensation. Many people make their first skydiving jump with an experienced and trained instructor. This type of skydive may be in the form of a tandem skydive which the instructor is responsible for any emergency, (which emergency is unlikely) and freeing the student to focus on learning how to skydive. Other training methods: static line, IAD (Instructor Assisted Deployment); and AFF (Accelerated Free fall) also known as Progressive Free-Fall (PFF) in Canada.
Despite the perception of danger, fatalities are rare. However, each year a number of people are hurt or killed parachuting worldwide.About 30 skydivers are killed each year in the US; roughly one death for every 100,000 jumps (about 0.001%). In the US and in most of the western world skydivers are required to carry two parachutes. Whether used or not the reserve parachute must be periodically inspected and re-packed by a certificated parachute rigger. In the event of not deploying the main parachute, a device called the automatic activation device (AAD- which many skydivers use) is used to open the reserve parachute at a safe altitude. Most skydivers wear a visual altimeter, but more and more many also use audible altimeters fitted to their helmet. Injuries and fatalities occurring under a fully functional parachute usually happen because the individual skydiving performed unsafe maneuvers or made an error in judgment while flying their parachute, typically resulting in a high speed impact with the ground or other hazards on the ground. 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 parallel to the ground during landing. The changing wind conditions are another risk factor, strong winds, and turbulence during hot days, the individual skydiving can get caught 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 is “canopy collisions”, or collisions between two or more individuals skydiving under fully inflated parachutes. When this occurs, the skydivers often must quickly perform emergency procedures to “cut-away” from their main canopies and deploy their reserve canopies with hopefully enough altitude. Canopy collisions are particularly dangerous when occurring at altitudes too low to allow the jumpers adequate time to safely “cut away” 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. Parachuting in poor weather, especially with thunderstorms, high winds, and dust devils can be very dangerous.
Skydiving can be practiced without jumping. Vertical wind tunnels are used to practice for free fall (“indoor skydiving” or “bodyflight”), while virtual reality parachute simulators are used to practice parachute control.
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.
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.
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.
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.
Skydiving 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 skydiver must have lighted altimeter (preferably accompanied with an audible altimeter). 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 in every direction, and to turn it on once they are under canopy. A 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 moon light. Once they get close to the ground, the moon light 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.
Stuff jumps are possible mostly with a rear door aircraft and a large, unpopulated space to jump over. In these jumps the skydivers jump out with an 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.