American Airlines Inc. canceled about 570 of today's flights as it continues its weeklong struggle with aircraft safety inspections.
Yesterday, the world's largest carrier scrubbed more than 930 flights nationwide - including 16 that were to depart from Logan International Airport.
That followed 1,094 cancellations on Wednesday and 460 on Tuesday as the carrier grounded all 300 of its
MD-80s are 45 percent of the airline's 655-aircraft fleet.
The Federal Aviation Administration requires that the lashes be spaced no more than 1 inch apart and face in the same direction, among other things. If installed incorrectly, the cord could chafe the wires and cause the plane to lose auxiliary hydraulic power for the landing gear or spark a fire near the fuel tanks.
The FAA said it will be checking airlines' compliance with its requirements through June 30, and as a result, travelers can expect more disruptions.
American's chief executive, Gerard Arpey, told reporters the airline has not found chafed wires in the 100 planes that it had completed inspections on this week. The carrier put those planes back into service yesterday morning.
The airline predicts it will have about 170 MD-80s in service this morning, 210 by tonight, and all 300 by to morrow night.
Arpey refrained from giving a date when things would return to normal.
"Obviously, it's going to take us several more days to get up to speed," he said. "I can't anticipate any more hiccups we might encounter."
Even when all of the 129-seat or 131-seat MD-80s, which are the oldest type of aircraft in American's six-model fleet, are ready to take off again, some passengers may find themselves holding tickets to nowhere.
"The more cancellations you have, the more crews are out of sequence, and the harder it is to restart it," said Thomas J. Kinton Jr., chief executive of the Massachusetts Port Authority, which runs Logan.
Because a single plane and crew may be scheduled to hopscotch through several cities and countries before returning to the originating airport days later, it can take several days to untangle out-of-sync operations, he said.
Yesterday's 16 canceled departures at Logan prevented about 1,600 passengers from flying to Chicago, Dallas-Fort Worth, or St. Louis. Roughly the same number of American flights and passengers from those cities did not arrive at Logan.
Logan has not been affected as much as American's hubs, where cancellations have left scores of travelers stranded in terminals or sent them to nearby hotels the airline is paying for.