NEW : American Airlines says 570 flights will be canceled Friday . `` I am profoundly sorry , '' chief executive of American says . American Airlines expects all of its MD-80 jets to be flight-worthy by Thursday night . Alaska Airlines , American cancel flights Saturday for safety checks .
NEW : American Airlines says 570 flights will be canceled Friday . `` I am profoundly sorry , '' chief executive of American Airlines says . American expects all of its MD-80 jets to be flight-worthy by Saturday night . Alaska Airlines , Midwest Airlines cancel flights Thursday for safety checks .