DALLAS — The Federal Aviation Administration, under fire for its handling of missed safety inspections at Southwest Airlines Co., said Tuesday it is ordering a check of maintenance records at all U.S. airlines.

The FAA's action applies to maintenance records on older Boeing 737 jets. FAA inspectors will check to make sure the airlines have complied with orders to perform the type of structural inspections that Southwest missed.

The FAA hit Southwest this month with a $10.2 million civil penalty for missing the inspections and then continuing to fly the planes with passengers on board even after realizing the mistake. Dallas-based Southwest plans to appeal.

Acting FAA Administrator Robert Sturgell said Tuesday the failure of Southwest to check the fuselages of its planes for cracks prompted him to ensure that other carriers were meeting the same requirement.

"While the data tell us flying is safer than ever, prudence dictates we take this additional precaution and conduct a special emphasis review," Sturgell said.

Sturgell said the first check of the airlines' maintenance records will be done by March 28 and a full audit finished by June 30.

The FAA said it would check compliance with at least 10 safety orders, called airworthiness directives, at every airline by March 28. The agency said a full audit covering at least 10 percent of all safety directives will be finished by June 30.

Southwest turned itself in to the FAA last March after discovering it had missed structural safety inspections on some planes. The company is conducting an internal review, and the FAA is also investigating how the lapses occurred.

After a drumbeat of bad publicity lasting more than a week, Southwest confirmed Monday that it was suspending plans to outsource some of its maintenance work to a contractor in El Salvador.

The Business Travel Coalition, a group representing corporate travel customers, said U.S. airlines outsourcing of maintenance costs rose from 26 percent in 1997 to 64 percent in 2006. The group called for more FAA oversight of repair facilities both in the United States and in foreign countries, with the cost of inspections borne by airlines that outsource maintenance work.