WASHINGTON (CNN) -- The nation's air safety watchdog ordered its inspectors Tuesday to confirm that airlines are complying with federal rules after revelations that Southwest Airlines flew dozens of aircraft without certain mandatory inspections.
Southwest Airlines grounded 44 planes after a report revealed that the airline skipped mandatory safety checks.
Federal Aviation Administration inspectors have been given 10 days to ensure that airlines are complying with 10 airworthiness directives -- orders to check or correct a known unsafe condition -- and to expand the review to include more directives thereafter.
The action comes after CNN, citing detailed congressional documents obtained in an investigation, revealed this month that Southwest Airlines flew at least 117 of its planes in violation of mandatory safety checks.
The House and Senate are planning hearings on the Southwest matter in April.
The day after CNN's exclusive report, the FAA began actions to seek a $10.2 million civil penalty against the airline for allegedly operating 46 Boeing 737s without conducting mandatory checks for fuselage cracking.
The amount of the proposed penalty "reflects the serious nature of those deliberate violations," the FAA said at the time.
The current action includes all aircraft models in the fleets of the airlines.
In a letter to inspectors and the industry, Nick Sabatini, the FAA's associate administrator for aviation safety, wrote that "One carrier's noncompliance with [airworthiness directives] makes it necessary for us to validate our system for overseeing your management of this regulatory requirement."
The acting administrator of the FAA depicted Tuesday's move as one taken in an abundance of caution.
"While the data tell us flying is safer than ever, prudence dictates we take this additional precaution and conduct a special emphasis review," Robert Sturgell said in a statement. Watch a former NTSB official talk about an 'enormously safe system' »
The order requires FAA inspectors to audit 10 airworthiness directives per fleet of planes by March 28.
The order does not specify which airworthiness directives will be checked, because the directives vary by aircraft type.
It also requires inspectors to complete a review of 10 percent of all airworthiness directives applicable to a fleet by the end of June.
Congress will probably take more steps to ensure the safety of the aviation system, predicted the chairman of the Senate Subcommittee on Aviation Operations, Safety and Security.
"The revelations surrounding the FAA's oversight of Southwest Airlines have thrown a cloud over the agency's safety work," said Sen. Jay Rockefeller, D-West Virginia.
"I strongly support the FAA's decision to implement spot checks of airline safety logs as a first step to rebuild public confidence."
Southwest placed three employees on administrative leave and began an internal investigation into the allegations that it flew planes without proper inspections after CNN aired its report.
Last week, the airline grounded 38 planes, along with six others that were already out of service, for inspections. The action forced the cancellation of several flights.
Southwest, without saying whether the 44 planes were among those in the CNN report, explained that the jets were inspected after an "ambiguity related to required testing" was found during a review of records. E-mail to a friend