Several of the nation's largest airlines have joined in a lawsuit to block stronger federal rules on crew rest during the longest international flights.
The airlines say that the Federal Aviation Administration bypassed usual rule-making procedures notifying American Airlines and Continental Airlines of the new rules in late October. They say that denied them the right to comment.
The lawsuit was filed Christmas Eve in the federal appellate court in Washington by Fort Worth-based American and Houston-based Continental, as well as by United Airlines, US Airways, JetBlue and two smaller carriers.
In their filing, the airlines said the new requirements would saddle them with "substantial burdens and costs." They charged FAA didn't show how the rules would improve safety.
The FAA rules would require that pilots on the longest international flights get more rest before flying again. The extra rest would be required even when only 10 percent of flights on a particular route exceed 16 hours.
The FAA was trying to address pilot fatigue, which unions and others have argued is a growing safety concern, especially on flights that can run 16 hours or longer.