Grounded airline RegionsAir on Monday filed suit against Sen. Richard Durbin, D-Ill., and the Federal Aviation Administration.
In the suit, RegionsAir - which operated 27 daily flights from Lambert Field for American Airlines before shutting down in March - alleges that federal inspectors improperly clipped its wings in a dispute over pilot-training procedures.
RegionsAir and regulators had signed a consent agreement over training policies earlier this year. However, RegionsAir said the FAA wouldn't help it solve the problems and that the agreement "was a pretense to terminate" its air carrier certificate.
On March 9, RegionsAir ceased operations after FAA inspectors showed up at its headquarters in Smyrna, Tenn.
The shutdown came after Durbin loudly criticized the airline's service record at several small Illinois airports, which "raises questions about the senator's abuse of power," said Michael Moulis, a lawyer for RegionsAir.
A spokesman for Durbin declined to comment and said the lawsuit, filed in the U.S. Court of Federal Claims in Washington, had been passed on to the Senate's office of legal counsel.
From Lambert Field, RegionsAir flew to nine small airports served as part of the government's Essential Air Service program. The routes have been given to other airlines, though not all through St. Louis. Some communities are still waiting for air service to resume.