Check the listing for details. Aviation “99” Propeller Ehart Pin. Condition: Used. Listed at 24.99 USD. This item is a vintage Ninety-Nines women's aviation club member lapel pin, commonly dating from the 1930s to the 1950s. Design: It features two interleaved number 9s with a propeller at the center. Significance: It represents the international organization of women pilots founded in 1929, with Amelia Earhart as its first president. Material: It is typically made of stamped brass or a gold-tone metal.