America's youth builds and flies model planes on miniature flying fields. Two American brothers proudly display their model of a photographic reconnaissance plane. They designed and constructed this small plane which takes photographs through a trap-door installed in the fuselage. Controlled by a time release, the trap door opens in mid-air and operates the shutter of a camera mounted in the plane. Model building has long been a popular hobby of American youth. In 1941 it was estimated that nearly three million boys were actively interested in model building. The National Aeronautics Association through its model divisions, the Academy of Model Aeronautics, has formed an Air Youth Division to bring a coordinated activity in aviation to American youngsters. Post war plans include an Inter-American Model contest to bring the young model builders of South American countries, the U.S. and Canada into friendly competition