On Friday, the country's top transportation official said air travel may get even more challenging if Congress fails to prevent the automatic federal spending cuts, due to begin March 1.
The cuts could lead to 90-minute airport waits, longer security lines, limited flights and closed regional airports, said Secretary of Transportation Ray LaHood.
"You're going to be delayed, going to have a real impact. A calamity, very painful. This is a big deal," said LaHood.
The Federal Aviation Administration says fewer air traffic controllers may be on duty, so travelers in major cities like Chicago could experience delays up to 90 minutes.
And the FAA may also close air traffic facilities at regional airports. Airports in Waukegan, DuPage, Aurora and Gary could be impacted.
Air traffic controllers at Midway Airport could be eliminated, ending 24-hour operations. The same could be true for DuPage and Peoria airports.
While the impact may not be felt immediately, experts say the fallout could be widespread.
The Associated Press contributed to this report.