Skyjumping is adventurous kind of sport in which the flyer exits the aircraft and comes down to Earth with the help of the Earth’s gravity, and during the last part of the flight the flyer uses a parachute to slow down at the descent. This sport can sometimes involve a free fall, a term used to refer the time when the flyer has not deployed his parachute and his body slowly accelerates up to terminal velocity. In the early 1930s, there were competitions for this sport, and later in 1952 it attained the status of the international sport.

The process of parachuting is not just a recreational activity or even a competitive sport; it is also used as a method of deployment in airborne forces by military personnel and also by forest fire fighters.

Usually operating at an airport, a skydiving centre can operate as a club or on the commercial basis. Individual jumpers can use a light aircraft like the Cessna 172 or 182 for this purpose. Turbine-powered large aircrafts can be used at drop zones (DZ). Among this aircrafts we can distinguish  the Cessna 208, GippsAero G A 8 Airvan, de Havilland Canada DHC-6 Twin Otter, or the short SC 7 Skyvan.

In a typical parachute jump, the flyer exits an aircraft (which is usually an airplane or sometimes even a helicopter or a balloon’s gondola) from an altitude of about 1,000-4,000 meters or 3,000-13,000 feet. If the skydiver is jumping from a lower altitude, then he or she can deploy the parachute immediately. But if the skydiver jumps from higher altitudes, the fall can be done as free fall for the first minute and then deploying the main parachute somewhere around 1000M or ~3,500 ft, landing a few minutes later.

Once the parachute is open, the skydiver controls the speed and also the direction using toggles which are on the steering lines attached to the parachute at its trailing edge, aiming at the landing spot and this coming to a gentle stop gradually. Modern parachutes are self-inflating wing of ‘ram-air’, similar to paragliders, and provide greater control of speed as well as direction. Experts specify that unlike parachutes, paragliders provide better range as well as lift, while conventional parachutes can absorb deployment stresses at a terminal velocity of approximately 190km/h. 

When a skydiver leaves the aircraft, for a few seconds he or she continues to move and travel in a forward direction simultaneously moving down die to the imparted momentum of the motion of the aircraft, which is called forward throw. The notion of a change in flight from horizontal to vertical is called ‘relative wind’ and more commonly called ‘being on a hill’. Skydivers do not experience any ‘falling’ sensation during a free fall because the air resists the body at speeds of 80km/h or 50mph. This resistance gives a feeling of direction and also of weight. At exit speeds of approximately 140km/h or 90mph, the fall feeling after exit is quite low, whereas if jumping from a stationary balloon or a helicopter this sensation is much more. For an orientation of belly to Earth’s surface, the skydiver can reach a terminal velocity of about 190 km/h or 120mph while for an orientation of head down to Earth where there is no acceleration towards ground, the skydiver can reach  up to 240-320 km/h or 150 to 200 mph.  Here the feeling is like some forceful wind.