A worker guides a United Airlines Boeing 787 as it is towed at O'Hare Airport in October 2025. (Photo by Dominic Di Palermo)TNSUnited Airlines took a big step in the battle with American for dominance at Chicago O’Hare International Airport, saying it will boost its summer departures schedule to 750, a record for the airport.United’s Chicago hub will become the world’s third largest single airline hub, behind only Atlanta and Dallas, each with about 950 daily departures, and ahead of Charlotte with about 65 ...