American, the nation's largest carrier, has now scrubbed more than 2,400 flights nationwide since Tuesday.
The airline canceled 183 flights out of Chicago's O'Hare Airport Thursday. The news isn't sitting well with travelers.
"I feel like the airline should have taken care of matters earlier and not gotten themselves into this situation," said Julie Wenzeo, passenger.One woman was scheduled to fly to the West Coast to see her son, a Division I volleyball player at Pacific University, just before he graduates. She was bringing him Lou Malnati's pizza to celebrate his Senior Night. She said she'll likely miss some of those activities. But another woman, who says her aunt was killed in a 1979 DC-10, American Airlines plane crash, said she prefers that the carrier be safer than sorry.
The question of how soon things will return to normal depends on how quickly the mechanics can inspect and fix the wiring on the grounded MD-80 jets.
"We have about 100 planes that are now ready to go back into service if they are not already flying so the cancellations on [Thursday] and [Friday] will be less and less," said Mary Frances Fagan, American Airlines spokesperson.
American officials say they thought they had the problem fixed two weeks ago but federal aviation inspectors said that nearly half its planes could violate a safety regulation designed to prevent fires.
"And if you're not in compliance you must ground the aircraft. And so when the FAA concluded that we were not in compliance this is what we had to do," said Dan Garton, executive VP of marketing.
"I've been watching aviation for a long time and I've never seen this kind of aggressive action to ground airplanes. The scale of this is staggering," said professor Joe Schwieterman, DePaul transportation expert.
American is doing what they can to keep disgruntled passengers at O'Hare happy by serving beverages and snacks.
"I think that it is nice of them to acknowledge the inconveniences that a lot of travelers are having today, and trying to compensate with warm orange juice is a start," said Janice Lang, air traveler.
The problems are spread across the country and airlines. Both Delta and Alaska airlines are also doing inspections on their MD-80 jets and canceling flights.
"For the most part, whatever we have available as far as our availability, we try to work with American to get our passengers where they need to go," said Sandra Gilbert, Alaska Airline employee.
The cancellations on American Airlines will extend into Saturday.
"We posted cancellations for today, tomorrow and Saturday, which will allow customers who want more assurance, they can look on aa.com and get a sense if a flight is canceled or still operating. They can check with certainty," said Fagan.
The MD-80s are American's midrange domestic workhorses, used primarily at its Chicago and Dallas.
The Associated Press contributed to this report. All rights reserved.