US airline Comair is suing the federal government over a fatal crash which killed 49 people in Kentucky last summer.
The crash at Blue Grass Airport was caused by pilots travelling the wrong way down a runway.
Comair blames the error on poor signage and markings during a repaving project at the airport.
The airline says the Federal Aviation Administration (FAA) should share the blame for the accident because it had understaffed the airport control tower, according to local media reports.
However, the FAA says it did not act negligently.
Earlier this month a court ruled Blue Grass Airport cannot be held responsible the crash.
Although the airport escaped blame, the National Transportation Safety Board (NTSB) has suggested improved runway markings at regional airports across the US.
