National Geographic : 1941 Jul
The National Geographic Magazine U. S. War Dept., Official Parachutes, "Life Rafts of the Air," Hung Up for Ventilation at Randolph Field About 1,000 chutes are in daily use at this Texas flying school. Once every 60 days they must be aired against mold, inspected, and repacked. Specially trained "riggers" care for them. Nobody can ride in an army plane without a parachute. Today parachutes are made of silk, rayon, or Nylon.