Unknown airport

An airport is a facility where airplanes take off and land. Airports are sometimes shown or mentioned in different episodes, but it's never specified which airport. There are a few different airports in the Chicago area, so it's unclear to which one the characters are referring.

Listed below are the different episodes that either show or mention an unnamed airport.

Episode 1: Fly the Unfriendly Skies
This particular unknown airport is where Bob Hartley's fear of flying group was beginning their trip to New York.

Episode 2: Tracy Grammar School, I'll Lick You Yet
Howard only mentioned this airport. He wanted to go there to pick up his DC-10 model for Career Day at Emily's school.