Think: Aviator sunglasses (obvi), cargo pants and shorts, checkered shirts, Merrell hiking boots, and the scent of Coppertone Sport SPF 100--multiply X 2.5 million over 7 days = AirVenture.
Couture: Vintage American dating to early-to-mid-20th century with a look adopted by popular culture. Baseball caps, aviator sunglasses, cargos and khakis, hiking boots and polo shirts. Pilots not only know how to fly - they know how to dress in the heartwarming way your Dad and Grandpa dress for leisure success.
I first started going to air shows around the U.S. when I was young, with my dad who is a small aircraft pilot. Because most of the attendees are men, the attire is pretty much uniform.
When the crowd is uniformly dressed, it allows the show to, well, show, which can be a pretty fascinating aspect of an airshow, where you see wooden airplane kits you make from home.