What Skydivers Do

Skydivers usually jump from an air­plane, although they also may leap from helicopters and balloons at various heights. A typical jump height is between 10,000 and 13,000 feet (3,050 and 3,960 meters). On August 16, 1960, Captain Joseph Kittinger of the U. S. Air Force stepped out of a balloon over New Mexico at a height of 102,200 feet (31,150 meters). He experienced a record-breaking free fall, skydiving for 4 minutes and 38 seconds before he opened his parachute at 17,500 feet (5,330 meters).

In free fall, a skydiver does not feel a falling sensation, even though speed through the air may reach 120 miles per hour (193 kilometers per hour). Skydivers do not experience the discom­fort of acceleration. During the descent, they may perform such maneuvers as turns, front and back loops, barrel rolls, and joining up with other skydivers in formations. There is a deceleration sensation when the parachute opens,

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О Members of a women’s skydiving team descend after opening their parafoils. Use of the parafoil has increased distance and maneuvering ability for skydivers.

slowing the descent to about 12 miles per hour (19 kilometers per hour).

The Parachutes

To end a dive, the skydiver first pulls out a pilot parachute. Measuring about 3 feet (0.9 meters), the pilot parachute is stored in a pocket on the harness, or rig. As this small parachute inflates in the wind, a cord known as the bridle operates the release mechanism for the main parachute and its lines. A rectan­gle of fabric (the slider) separates the

THE PARAFOIL

The invention in the 1960s of the wing parachute, or parafoil, revolutionized sports parachuting. The modern para­chute, known as a ram air wing, flies almost like a paraglider. The canopy contains seven to nine panels, or cells, open at the front so that air can enter.

The parachutist can alter the amount of air inside the canopy by twisting a handgrip. By tugging on the steering lines, the parachutist can make turns and steer toward a landing site.

parachute lines into four groups and works its way down until the canopy is fully open and the slider is just above the skydiver’s head.

A skydiver carries two full-size para­chutes, one of which is kept in reserve. The minimum safe height for opening a parachute is around 2,000 feet (610 meters). This height gives sufficient time for the skydiver to open the reserve parachute if the main parachute fails to function. Many skydivers carry an automatic activation device (AAD), which opens the reserve parachute at a safe altitude if the skydiver fails to open the main parachute. Skydivers always carry an altimeter so they know at what height to open the parachute. If the main parachute malfunctions after it has been opened, the skydiver uses one handle to discard it and pulls another

handle (on the parachutist’s chest) to open the reserve parachute.

Rectangular canopies are better than traditional round canopies for competition jumping as they are much easier to steer. A rectangular canopy will not collapse should another parachutist fly beneath it and take its air. Using these modern canopies, skydivers can fly in stacks, one above the other. An experienced skydiver with a modern parachute can fly cross-country for as much as 10 miles (16 kilometers), reach­ing speeds of up to 30 miles per hour (48 kilometers per hour) over the ground. He or she can perform dramatic maneuvers such as the swoop: a fast, downward approach before leveling off just above the ground.