Parachutes

A parachute enables a person to execute a controlled fall from a tremendous height and to do so in relative safety. The parachute does this by creating drag and thereby slowing the person's descent. The word parachute derives from the French words para, meaning to protect or shield, and chute, which means to fall. The word parachute means to protect from a fall.

Parachuting has had both military and recreational applications. The average recreational jump is done from an airplane, helicopter or balloon at a height of about 12,000 feet. When a parachutist jumps from an aircraft, they are traveling the same speed as the aircraft, which is about 90 to 110 miles per hour. This initial period, after the jump, is known as "freefall" because the actual chute is not yet deployed. During the first 10 seconds of this freefall, the skydiver may accelerate to about one hundred and fifteen to one hundred and thirty miles per hour while going straight down.

The rate of fall can be controlled somewhat by the position of the skydiver's body. By diving head first, the speed of fall can be altered up or down ten to twenty miles per hour. Jumping in a "standing position" will allow experienced skydivers to reach speeds of one hundred sixty to one hundred eighty miles per hour.

The record freefall speed is three hundred and twenty one miles per hour. The descent is slowed again to around one hundred ten miles per hour just prior to deploying the chute and then the descent rate is around one thousand feet per minute.

With the chute deployed, the skydiver can control direction and speed using cords called "steering lines" and hand grips called "toggles." While making a sharp turn, the descent rate may go up to one thousand five hundred feet per minute. The skydiver aims for his "drop zone."

As far as the actual landing goes, the old round canopy has been replaced with a rectangular one that acts like a wing or airfoil. They act more like gliders than umbrellas and allow exceptional maneuverability. With the new design canopy, even a novice can experience a soft touch down.

The highest parachute jump on record was made by a Captain Joseph W. Kittinger Jr. on August 16th, 1960 while working for the Aerospace Medical Research Laboratories at Wright-Patterson Air Force Base, investigating escape from high altitudes. Captain Kittinger jumped from a balloon supported gondola almost 102,800 feet above the earth. He reached a falling speed of 714 miles per hour, before his chute opened at 18,000 feet.