(CNN) -- The chief executive of American Airlines, which has grounded almost 2,500 flights over the past three days, accepted "full responsibility" Thursday for failing to meet government inspection standards.



"I am profoundly sorry that we've gotten ourselves into this situation, and I thank our customers for their patience under very difficult circumstances," American CEO Gerard Arpey said Thursday afternoon.



The airline canceled 933 flights on MD-80 jets Thursday and announced  570 would be scrapped Friday.



Potential wiring hazards in wheel wells that could cause fires or problems with landing gear prompted the action.



American canceled several hundred flights for the same reason about two weeks ago.



Earlier Thursday, American said it expected all of its MD-80 jets to be flight-worthy by Saturday night.



The airline has offered to make amends to travelers with refunds, vouchers and compensation for overnight stays.



The cancellations have delayed and stranded more than 140,000 passengers.



Roger Frizzell, an airline spokesman, said the inspections involve technical compliance as opposed to flight safety.  Watch how air travelers deal with disruptions »



Although American was most affected by the inspections, the Federal Aviation Administration's orders for safety checks have also affected Southwest Airlines, United Airlines, Delta Air Lines, Alaska Airlines and Midwest Airlines, which was the latest airline to ground planes: 13 on Thursday.



The FAA launched its inspection campaign in March, after CNN obtained documents given to congressional investigators that showed more than 100 Southwest aircraft had not had mandatory safety inspections.   At a Capitol Hill hearing Thursday, the head of the Federal Aviation Administration's safety division, Nicholas Sabatini, was told that his agency's performance was woeful.



"I think [it's] approaching losing the confidence of the American people and the Congress," said Sen. Jay Rockefeller, D-West Virginia.



Lawmakers said the agency has become too close to the airline industry.



Sabatini defended the FAA's record but said any lapse was cause for concern.



"We found we had achieved 99 percent safety compliance," he told lawmakers. But, he added, "It's the other 1 percent that keeps me up at night."



Passengers scheduled to fly on an American Airlines MD-80 between Tuesday and Friday can receive a full refund or apply the value of their ticket to a future flight, the airline said.



People who stayed overnight as a result of a canceled flight can go to the company's Web site to inquire about receiving compensation.



Arpey said that the MD-80 has been a great plane for American Airlines and that the inspection problems should have "no impact on our long-term fleet plan."



"The FAA is stepping up their surveillance and doing their job," Arpey said. "In this case, we failed to get it right, and we're trying very hard to get it right."



He said American plans to hire an independent consultant to examine the company's inspection system.



Meanwhile, airports are doing their best to keep frustrated travelers happy.



"Getting stuck at the airport is not like a day at the beach, but we sure are trying to make passengers as comfortable as possible," said Ken Capps, vice president of public affairs for Dallas/Fort Worth International Airport in Texas.



Eateries were staying open all night, some provided free pastries and coffee, and some even handed out diapers.



The situation at American's hub at O'Hare International Airport in Chicago, Illinois, "was what you might see on a normal Thursday morning," CNN's Susan Roesgen reported. American employees handing out free coffee and granola bars found few takers.  Watch a report from O'Hare »



At Hartsfield-Jackson International Airport in Atlanta, Georgia, American passengers reported frustration but complimented the carrier's efforts to get them to their destinations.



"We were rerouted," said Chad Duncan of San Angelo, Texas, who was in Georgia to watch practice rounds of the Masters golf tournament. "They were very helpful and everything, but it's frustrating. Instead of having one stopover, we now have three
What caused the cancellation? What type of jet did experts expect to be flight-worthy? Which day of the week did Alaska and Midwest airlines cancel their flights? How many flights will be cancelled according to American Airlines? What is wrong with the planes?
failing to meet government inspection standards. MD-80 Thursday. 2,500 Potential wiring hazards in wheel wells that could cause fires or problems
question: What caused the cancellation?, answer: failing to meet government inspection standards. | question: What type of jet did experts expect to be flight-worthy?, answer: MD-80 | question: Which day of the week did Alaska and Midwest airlines cancel their flights?, answer: Thursday. | question: How many flights will be cancelled according to American Airlines?, answer: 2,500 | question: What is wrong with the planes?, answer: Potential wiring hazards in wheel wells that could cause fires or problems