Rockefeller, Cantwell to airlines: Prove you're not keeping lost FAA taxes

Rockefeller and Cantwell's letter went to 12 airlines: Delta Air Lines, United-Continental, American Airlines, Southwest Airlines, US Airways, Alaska Air Group, JetBlue Airways, Republic Airways Holdings, Hawaiian Airlines, Spirit Airlines, Virgin America and Allegiant Air.

The funds at issue would normally be deposited into the federal Aviation Trust Fund. However, the money has not been deposited into the trust fund for almost a week because the last appropriations bill for the FAA expired last Friday at midnight. The following day, about 4,000 FAA workers were furloughed.

The House and Senate have remained gridlocked almost a week later.

The bill is being held up by a provision in the House version of a short-term extension of the FAA funding bill that eliminates some subsidies for rural air service through the Essential Air Service program. A longer-term bill has been bogged down by a House effort to undo rules on unionization of railroad and airline employees that would make it harder for them to vote to collectively bargain.

The FAA has not had a long-term authorization bill since the last measure that was passed in 2004 expired in 2007.

Earlier Thursday, Transportation Secretary Ray LaHood criticized airlines for keeping the lost FAA revenue.

"These are people who are planning a vacation," he said during a White House press briefing Thursday. "People who are buying tickets, who are living on a budget.

"That's not right, and I've made that known to them," LaHood said of the airlines.