National Geographic : 1926 Dec
EXPLORING THE EARTH'S STRATOSPHERE Official Photograph, U. S . Army Air Corps A PARACHUTE PLUNGE The "chute" is made of a very light, strong grade of silk and requires only about three seconds in which to open after the jump is made and the rip cord or releasing device is pulled. The small umbrella trailing out to the right is called a pilot chute. It is opened by "safety-pin" springs and serves to pull the main parachute out of its pack and into position. Although a parachute ordinarily will open within 200 feet of fall, nothing less than 500 feet is considered a safe jumping distance.