American canceled 595 flights nationwide Friday, including 87 at O'Hare Airport. That brings this week's total to nearly 3,100 cancellations.
The airline is inspecting the wiring on MD-80 jets. Almost 1,000 flights were canceled Thursday. Two-hundred-fifty-thousand passengers have been affected.
American has lost tens of millions of dollars due to the delays over the past two weeks. The airline hopes all of its MD-80 fleet will be back in service by Saturday night.