A GAO report released Thursday suggested Congress could tax bag fees and other ancillary airline services to help offset an expected $25 billion shortfall in FAA's Airport and Airway Trust Fund

, which supports airport infrastructure and air traffic control. "If Congress determines that the benefit of added revenue to the Trust Fund warrants taxation of optional airline service fees, such as baggage fees, then it should consider amending the Internal Revenue Code to make mandatory the taxation of certain or all airline-imposed fees and require that the revenue be deposited in the Trust Fund," according to the report submitted by General Accountability Office director of physical infrastructure Gerald Dillingham.