A U.S. district judge late Wednesday ordered American Airlines pilots to return to work after 11 percent of them called in sick.

U.S. District Judge John McBryde issued the temporary restraining order after American accused the pilots of staging a "sickout," and sought to force them back to work.Negotiations between American and the union on a new contract for the pilots have been under way for 14 months.

On any given day, officials said, about 4,500 pilots fly for American. On Wednesday, 529 of them - or 11 percent - called in sick. That number was 70 percent higher than usual for pilots who call in sick, sources at the airline said.