American Airlines says it is canceling 570 flights Friday.

That will mark the fourth straight day of large-scale cancellations since the nation's largest airline learned that the wiring on 300 planes needed to be re-inspected.

American's chief executive said Thursday that the cancellations will cost the company tens of millions of dollars, but he says American can withstand the losses.

CEO Gerard Arpey says he takes full responsibility for the airline's failure to comply with a federal safety rule on electrical wiring in its MD-80 aircraft.