Unidentified photographer 1930s Autogiro mail service, USA
Gelatin silver print, snapshot Rosenthal-Shilling Collection (Wikipedia) First Scheduled Autogiro Air Mail Route In The World. When improvements in helicopters made them practical, autogyros became largely neglected. Also, they were susceptible to ground resonance. They were, however, used in the 1930s by major newspapers, and by the United States Postal Service for the mail service between Camden Central Airport, New Jersey, and the top of the post office building in downtown Philadelphia, Pennsylvania.