American Airlines said it would cancel another 250 flights Saturday, putting the number of flights nixed by the carrier this week well above 3,000.
The airline said Friday afternoon that Saturday's cancellations will occur mostly in the morning and midday. It expects to have all its MD-80 aircraft fixed, inspected and ready to go by late afternoon.
American is planning on resuming a full schedule late Saturday and "certainly by Sunday."
With more than 3,000 flights canceled this week, American Airlines is still scrambling to accommodate passengers. The airline canceled 595 flights Friday, in addition to the thousands it had canceled since Tuesday.
By Friday morning, more than 225 of the carrier's 300 MD-80 jets were back in service. The airline is rotating the planes back into service once inspectors re-examine wiring, and expects to get the rest of them back in the air by Saturday night.
Delta, Midwest and Alaska airlines also canceled flights this week for inspections, though in smaller numbers than American.
But as the airlines continue to reaccommodate customers, many travelers stranded in the nation's airports are raising the same question: "Why would they come out with a plan to ground all the planes at one time?" asked Sanjay Amin, a traveler trying to get from Chicago to Dallas.
Congress is asking the Federal Aviation Administration the same question.
At a Thursday aviation hearing on Capitol Hill, Sen. John D. Rockefeller IV, D- W.Va., wondered whether the FAA could have avoided mass cancellations had it conducted more frequent and regular compliance checks. He wondered whether the American planes would have been grounded if the news of the uninspected Southwest planes had not become public.
"If this had been identified at another point in time, I believe the outcome would have been the same," said Nicholas Sabatini, the FAA's associate administrator for aviation safety. Sabatini praised the work the FAA has done so far in "extending the safest period in aviation history."
The FAA recently found airlines were 99 percent compliant with safety directives after nearly 2,400 audits at 117 air carriers.
Rockefeller called this week's cancellations "catastrophic economically" and "an embarrassment to the nation."
"This has obviously caused a volcanic disruption which is, in and of itself, unthinkable," he said.
Both House and Senate lawmakers accuse the FAA of having too close a relationship with the industry it regulates — at the expense of airline safety. Echoing the sentiments expressed at last week's House hearing, lawmakers and aviation experts said Thursday that this week's cancellations aren't entirely American's fault, but also the FAA's fault for running a broken system.
"A slew of aircraft groundings indicate that there are problems within the system that are not being addressed," said Tom Brantley, president of Professional Aviation Safety Specialists.
"You don't have to play patty-cake with the airlines to be nice to them," House Transportation and Infrastructure Committee Chairman James L. Oberstar, D-Minn., told ABC News on Thursday. "You do have to oversee that they're doing their job right, especially in an era of outsourced maintenance."
On Thursday afternoon, American's chairman and chief executive Gerard Arpey was apologetic.