Membership was limited to those who piloted a glider, gas balloon, or airplane, prior to December 17, 1916, covering the entirety of the pioneer era of aviation, and just over two years into World War I. The cutoff date was set at December 17 to correspond to the first flights of Wilbur and Orville Wright. 1916 was chosen as a cutoff because a large number of people were trained in 1917 as pilots for World War I. Twelve of the aviators were women.
