WASHINGTON (CNN) -- The Federal Aviation Administration is putting the public at risk with lax oversight and a too-cozy relationship with the airlines, a top lawmaker and aviation experts said Tuesday.
The FAA has shown a dangerous lack of enforcement compliance with inspection requirements, resulting in thousands of people flying on potentially unsafe aircraft, said Rep. James Oberstar, the chairman of the House Committee on Transportation and Infrastructure.
"This is the most serious lapse in aviation safety at the FAA that I've seen in 23 years," the Minnesota Democrat said in an interview with CNN, a position he restated at a news conference Tuesday.
"The result of inspection failures and enforcement failure has meant that aircraft have flown unsafe, un-airworthy and at risk of lives," he said.
Oberstar scheduled hearings to begin Thursday, after a congressional investigation uncovered that discount airline Southwest Airlines kept dozens of aircraft in the air without mandatory inspections -- and, in some cases, with defects the inspections were designed to detect.
CNN was first to report on the investigation in early March after obtaining documents submitted to the congressional investigators by two FAA inspectors who said FAA managers knew that the Southwest planes were flying illegally and did nothing about it.
The day after CNN's report, the FAA began actions to seek a $10.2 million civil penalty against Southwest for allegedly operating 46 Boeing 737s without conducting mandatory checks for fuselage cracking.
"Allowing an airline to fly passengers on aircraft with a known unsafe condition in my opinion is criminal," one inspector wrote.
FAA spokeswoman Laura Brown said the agency would "talk in great detail about all this" at the hearing.
"We have found consistently high rates of compliance with our audits and inspections," she said, adding that the agency intends to add additional measures to "provide inspectors the opportunity to report concerns up the chain of command."
The FAA also has scheduled a news conference for Wednesday, when the results of new inspections are expected to be announced.
The inspectors wrote that Southwest, which carried more passengers in the United States last year than any other airline, flew at least 70 planes beyond a mandatory inspection on the rudder unit, part of the steering mechanism, some of them as much as 30 months beyond the mandatory rudder inspection.
The airline also flew at least 47 planes beyond a mandatory inspection of the fuselage, or skin, of the planes for possible cracks, the inspectors said. When the inspections were carried out, six of the planes were found to have possibly dangerous cracks, they said.
In that group, Southwest flew at least 1,457 fights, according to the documents. Those flights carried an estimated 200,000 paying passengers, Congressional investigators said.
The FAA inspectors wrote that the airline knew it was in violation of safety rules by continuing to fly the uninspected 737s. At least one of the FAA inspectors wrote that he had been complaining about increasing problems like these for years at the Southwest regional FAA office, which oversees Southwest Airlines.
The two inspectors are to appear before Oberstar's committee Thursday.
In the wake of the congressional inquiry, the FAA ordered its inspectors to ensure that airlines were complying with 10 "airworthiness directives" -- orders to check or correct a known unsafe condition -- and to expand the review to include more directives thereafter.
Oberstar said that this week's hearings, though focusing on Southwest, were also important to show a larger trend: that the FAA is far too close to the airlines it regulates.
"It reflects an attitude of complacency at the highest levels of FAA management, a pendulum swing away from vigorous enforcement of regulatory compliance toward a carrier-friendly, cozy relationship with the airlines," he said. "This can lead to accidents and to fatalities." E-mail to a friend