Skydiving Fundamentals
Skydivers always have two parachutes , in order to increase safety. The main parachute is carried in a deployment bag on the back of the skydiver , while the reserve one, a completely separate parachute system is also carried on the back, should there occur any problems with the main parachute.
A number of preparations must be done by a skydiver before jumping. The first thing to keep in mind is that the equipment must be properly packed. The plan of the jump has to be coordinated with the pilot of the aircraft. Weather and wind conditions are the keys to deciding the best area for the jumpers to exit the aircraft. Jumpers practice maneuvers that they will do in the air, before getting into the aircraft. Afterwards, the jump order and a landing approach pattern must be determined, so that any possibility of mid-air collisions is outruled. In the reverse order of exit, the skydivers get on board of the aircraft, and then they have to strap themselves to the floor or to specially designed jump seats.
The aircraft can go up to between 3.200 and 4.200 m, meaning from about 10.500 to 13.800 ft. During the jump run, that is the during the final approach over the jump site, the pilot and the the progress of the aircraft and the jumpers. They will line up at the exit door as soon as they have found the right spot. In order for some jumpers to climb out in advance, handholds and steps make it more easy. These actions help skydivers in each group to leave the aircraft as close together as possible and to do all the maneuvers they have already planned during the short fall, that only lasts for one minute.
As their turn comes, every skydiver takes a step from the aircraft and starts free-falling. During the first 10 to 12 seconds, when the air resistance equals the pull of gravity, the rider can reach maximum speed. Skydivers of average size fall approximately 320 to 450 m , that is 1,050 to 1,480 ft every five seconds, reaching 190 to 240 km/h , that meaning 120 to 150 mph. The skydivers can also move horizontally in the air, reaching speeds of up to 80 km/h. While they are free-falling in the air, riders change their body position in order to do their maneuvers. Skydivers can streamline their bodies or stretch out their arms and legs to catch the air in order to become more or less aerodynamic. This is how they can increase or decrease their velocity.
All maneuvers are stopped at about 1.200 m, that is 3.900 ft. Riders turn away from each other and they form their bodies into a tracking position, meaning a straight, stiff, headfirst posture. Skydivers turn away from each other and give the signal to deploy their parachutes by waving their arms. This of course happens when the riders have gained sufficient space from one another.
The riders extract a small pilot chute that is folded in a pouch on the parachute system, thus beginning the deployment. This pilot chute fills with air in order to pull the parachute container open. Then it can drag the packed main parachute from the jumper's backpack. The main parachute will fill with air and get the shape of a wing, once it is opened . This parachute can slow down the fall of the rider, by becoming a canopy. The total deployment from pilot chute to open, maneuverable canopy lasts no more than 2 to 5 seconds.
A parachute canopy can reach the speed of around 32 km/h or 20 mph and while descending, it can reach 20 km/h or 12 mph. The parachute can be controled with the help of two toggles, that are gripped above the head with the hands. At several points along one side of the trailing edge of a wing, can a toggle be attached. The parachute can be slowed down on that side , by simply pulling one of the toggles. In this way, the skydiver turns in that direction. A parachute can flare, or slow the descent and forward speed of the jumper at the same time, should the rider pull both of the toggles at a time.
Usually, parachute rides last up to two or three minutes. By spacing themselves out and landing in an orderly sequence, a very organized group can reduce the possibility of a collision in the air. Every skydiver will face the wind to reduce forward speed at every landing site. The riders must make the landing softer by flaring the parachute seconds before the actual landing. Should the landing turn out to be rather difficult, a jumper can roll forward in order to avoid injury to their arms and legs. This is not the case of the more experienced riders, who use to land on their feet , while running .