In 1942, the first parachute jump in the U.S. using a nylon parachute was made by Adeline Gray. Cotton had been superceded by silk cloth as a higher-strength, lower-weight parachute fabric. Oriental high-volume sources of the silkworm product were cut off during WWII. Fortunately, nylon, a newly invented synthetic substitute produced by the DuPont Co was available, as exhibited at the 1939 World's Fair. Nylon parachutes had been tested with dead weights, but the military needed a live trial to confirm personnel use. Gray, a parachute rigger at the Pioneer Parachute Company volunteered. She jumped from an aircraft flying from Brainard Field, Hartford, Conn. convincing an audience of 50 critical army and navy observers.«