U.S. Sens. Dick Durbin and Mark Kirk are questioning airline fare increases after a ticket tax holiday was created by the partial shutdown of the Federal Aviation Administration.
The two Illinois senators have sent a letter to the head of the Air Transport Association asking why most carriers aren't passing the savings along to customers.
Other senators also are putting pressure on the carriers about the fare increases, and so is U.S. Transportation Secretary Ray LaHood.
The FAA shutdown eliminated the airlines' authority to collect ticket taxes, which funds the FAA and airport construction. But nearly all carriers raised fares equal to the taxes.
Kirk, a Republican, and Durbin, a Democrat, say they worry the recent price increase is "a collective effort to take advantage of federal inaction."