Midwest Airlines became the latest airline to ground planes and cancel flights Thursday to re-inspect a wiring mechanism, the same concern that has forced American to cancel more than 2,400 flights, The Associated Press reported.
"If we do uncover any safety issues from these audits, the carriers will have to make a business decision as to how to deal with the issue," Federal Aviation Administration spokesman Les Dorr said.
Nicholas Sabatini -- the FAA official who ordered the broader safety audits last month after allegations surfaced that Southwest Airlines was found to have flown planes that missed inspections -- will face questions over the agency's response to recent safety concerns Thursday during a Senate hearing to evaluate aviation operations.
The first round of airline safety audits, conducted over a two-week span last month, checked 10 airworthiness directives that apply to each carrier's fleet. The second phase, which runs through June 30, will check 10 percent of the orders that apply to each airline's fleet, according to the AP.
On Wednesday, American Airlines, the world's largest carrier, cancelled 850 flights after calling off another 500 on Tuesday in order to reinspect and possibly rework the wiring of its widely-used MD-80 fleet.
Delta Air Lines also cancelled flights in March to complete wiring inspections.
Officials said that passenger safety was never compromised. American Airlines operates 2,300 flights daily and the cancellations have left thousands of customers stranded.
"We are aware and sympathetic ... 100,000 people being stranded is extraordinary," FAA spokeswoman Lynn Tierney said, according to the AP. "But the role is clear, it's a regulator's role and you have to enforce the regulations. We understand the disruption this causes, but (the airlines) had 18 months to complete the work."
Tierney is referring to a safety order issued in September, 2006, on the Boeing Co. MD-80 aircraft that have been grounded by American, Midwest and other airlines in recent days.
Air passengers, meanwhile, are taking a cautious view of American Airlines' promises to quickly resolve any problems.
American has also declined to say how much it would spend on travel vouchers and hotel rooms for stranded travelers and overtime for mechanics.
"They say our flight is leaving at 3:55 p.m., but do you think we trust them?" Kathy Neer of Santa Fe, N.M., told the AP about being caught up in waves of cancellations en route to a vacation in Paris. "After being burned twice, we're a little skeptical."