Airline officials said Friday that a second round of inspections had been completed.

Reacting to a $10.2 million fine issued by the Federal Aviation Administration and allegations that the FAA and Southwest maintenance personnel had known of previous regulatory lapses, the airline announced Wednesday it would ground and inspect 44 jets.

Southwest said those inspections found six planes with fuselage damage that could be quickly repaired, and that it had resumed normal operations, the Dallas Morning News reported.

"This action … raises serious questions about whether (the) FAA adequately followed up" on the airline's admission in March 2007 that some planes had not been inspected on time, said Rep. James Oberstar, D-Minn., who is heading a congressional investigation.

Two whistle-blowers at the FAA have said the agency's relationship with the airline was too cozy. Oberstar's committee is investigating ties between FAA supervisor Douglas T. Gawadzinkski and Southwest regulatory official Paul Comeau the newspaper the report said.

Gawadzinski did not ground the planes or tell supervisors about his decision, the report said.

Comeau used to work at the FAA, it said.