For Chicago-Sao Paulo flights, you can use Chicago Rockford Intl. Airport, Gary International Airport, Merrill C Meigs Airport, Chicago Midway Intl. Airport, O'Hare Intl. Airport as departure airport, and Sao Paulo - Congonhas - Deputado Freitas Nobre Airport, Governor Andre Franco Montoro Intl. Airport, Viracopos Campinas Intl. Airport for arrival.