May 22, 2008 by TMO
Today it is performed as a recreational activity and a competitive sport, as well as for the deployment of military personnel Airborne forces and occasionally forest firefighters.
A typical jump involves individuals jumping out of an aircraft (usually an airplane, but sometimes a helicopter or even the gondola of a balloon), travelling at 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 ft). the jumper can control his or her direction and speed with “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. All 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.
By manipulating the shape of the body a skydiver can generate turns, forward motion, backwards motion, and even lift.