Parachuting



Parachuting, or skydiving, is a recreational activity, competitive sport and method of deployment of military personnel (and occasionally, firefighters). It involves the breaking of a free fall from a height through the use of a parachute.

Procedure

Typically, a trained sky diver (or jumper) and a group of associates meet at an isolated airport. 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, an individual jumper would go up in a Piper Cub aircraft for reasons of economy.

A jump involves individuals jumping out of aircraft (usually an airplane, but sometimes a helicopter or even the gondola of a balloon), usually travelling at approximately 4000 metres (around 12,000 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, 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.)

4-way formation skydiveSkydivers skydive because it is the closest one can get to the dream of flying. Experienced skydivers will tell you that in freefall, one can do anything a bird can do, except go back up. But skydiving is the only aerial activity where the body is the flying instrument instead of a machine, however simple. Some jumpers explain the attraction to skydiving by adrenaline addiction. Others suggest a suicidal disposition, but these people are usually not skydivers.

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 (Advanced Freefall). See below.

Skills

Parachuting has complex skills that can take thousands of jumps to master but the basics are often fully understood and useful during the first few jumps. There are four basic areas of skill: basic safety, free fall maneuvers, parachute operation, and landing.

Basic safety includes knowing how and when to: do a gear check, exit normally, react in an emergency, deploy a parachute, handle common malfunctions, pick a landing area, and set up and execute a landing. Most national sport organizations certify instructors, most operators who fly skydivers retain an instructor, and all certified instructors can teach the basics well enough for a student to be licensed by the national sport organization.

In freefall most skydivers start by learning to maintain a stable belly to earth "box" position. In this position the average fallrate is around 125 mph. Learning a stable box position is a basic skill essential for a reliable parachute deployment. Next, jumpers learn to move or turn in any direction while remaining belly to earth. Using these skills a group of jumpers can create sequences of formations on a single jump, a discipline known as relative work (RW). In the late 1980s more experienced jumpers started experimenting with freeflying, falling in any orientation other than belly to earth. Today many jumpers start freeflying soon after they earn their license, bypassing the RW stepping stone.

Choosing when to deploy the parachute is a matter of safety. A parachute should be deployed high enough to give the parachutist time to handle a malfunction should one occur. Two thousand feet is the practical minimum for advanced skydivers. In freefall, skydivers monitor their altitude meters to decide when to break off from the formation (if applicable) and when to open their parachutes. Many skydivers open higher to practice flying their parachute. On a "hop-and-pop," a jump in which the parachute is immediately deployed upon exiting the aircraft, it is not uncommon for a skydiver to be under canopy as high as 4000 or 5000 feet.

Flying the parachute has two basic challenges: to land where planned, often on a target; and to avoid injury. On a more advanced note, some skydivers enjoy performing aerobatic maneuvers with parachutes.

White sand circular target at a drop zoneA modern parachute or canopy "wing" can glide substantial distances. Elliptical canopies go faster and farther, and some small, highly loaded canopies glide faster than a man can run, which can make them very challenging to land. A highly experienced skydiver using a very small canopy can achieve over 60 mph horizontal speeds in landing.

A good landing will not have any discomfort at all, and will land the skydiver within a few feet of his intended location. Champion accuracy skydivers routinely land less than two inches from the center of a target even in competitions.

Nowadays, most of the skydiving related injuries happen under a fully opened and functioning parachute, the most common reasons for these injuries are badly-executed, radical maneuvers near to the ground, like quick turns, or too-low or too-high landing flares.