Parachuting, or skydiving, is an activity involving a free-fall from a height using a parachute.
The history of skydiving began with a descent from a balloon by Andr-Jacques Garnerin in 1797. Skydiving has been used by the military since the early 1900s, including use in World War I and World War II. Early competitions date back to the 1930s, and it became an international sport in 1951.
Today it is performed as a recreational activity and a competitive sport, as well as for the deployment of military personnel and occasionally forest firefighters.
Typically, a trained skydiver (or jumper) and a group of associates meet at an isolated airport, sometimes referred to as a dropzone. A fixed base operator at that airport usually operates one or more light cargo aircraft, and takes groups of skydivers up for a fee. In the earlier days of the sport, it was common for an individual jumper to go up in a Beech 18 or Douglas DC-3 aircraft for reasons of economy.
A typical jump involves individuals jumping out of aircraft (usually an airplane, but sometimes a helicopter or even the gondola of a balloon), travelling at approximately 4000 metres (around 13,000 feet) altitude, and free-falling for a period of time before activating a parachute to slow the landing down to safe speeds.
Once the parachute is opened, (usually the parachute will be fully inflated by 2,500 feet.) the jumper can control his or her direction and speed with cords called “steering lines,” with hand grips called “toggles” that are attached to the parachute, and so he or she can aim for the landing site and come to a relatively gentle stop in a safe landing environment. Most modern sport parachutes are self-inflating “ram-air” wings 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.)
Many skydivers skydive because it is the closest one can get to the dream of flying. Skydiving is the only aerial activity where the body is the flying instrument instead of a machine. By manipulating the shape of the body, as a pilot manipulates the shape of his aircraft’s wings, turns, forward motion, backwards motion, and even lift can be generated. Experienced skydivers will tell someone that in freefall, one can do anything a bird can do, except go back up.
Skydivers generally do not experience a “falling” sensation due to the fact that they reach terminal velocity (around 120 mph for belly to Earth orientations, 150-200 mph for head down orientations) and are no longer accelerating towards the ground. This lack of “falling” sensation does not exist when they leave the plane, as their momentum from the plane causes the acceleration forces to be slow as their direction of travel changes from the direction of the airplane’s flight to the direction pulled by the force of gravity. Skydivers call this transition period “the hill”, and the amount of distance they fly with the plane due to the momentum is called “forward throw”. Acceleration is what causes the “stomach in your throat” feeling on a roller-coaster or other amusement park rides.
Most skydivers 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 jumpmaster is responsible for the stable exit, maintaining a proper stable freefall position, and activating and controlling the parachute. With training and experience, the fear of the first few jumps is supplanted by the tact of controlling fear so that one may come to experience the satisfaction of mastering aerial skills and performing increasingly complicated maneuvers in the sky with friends. Other training methods include static line, IAD (Instructor Assisted Deployment), and AFF (Accelerated Free-Fall) aka Progressive Free-Fall (PFF) in Canada.