The FAA fined Southwest Airlines $10.2 million Thursday for allowing 46 jets to fly beyond the dates they were required to undergo structural inspections. Subsequent inspections found some damaged aircraft, although none of the problems resulted in accidents.

But FAA inspector C. Bobby Boutris said he had written memos in 2003 warning his supervisors the airline wasn't keeping up with maintenance programs. Another inspector, Douglas Peters, said FAA officials had objected to his concerns about the airline, USA Today said.

The underlying cause: managers at the FAA and Southwest were too cozy with one another, the report alleged.

The inspectors are to testify April 3 in front of the federal Office of Special Counsel, which monitors whistle-blowers.