Senate Committee on Commerce, Science and Transportation Chairman Jay Rockefeller (D-W.Va.), the bill's sponsor, told The Hill that there will be some "hard decisions" but that lawmakers need to do "whatever it takes."
Rockefeller expressed frustration that the bill has stalled for so long and said the measure needs to get done and be sent to President Obama for his signature sometime this year.
The bill needs to move forward mainly to get the nation's air traffic control system upgraded, he said.
The measure calls for a transition from World War II-era radar technology to a satellite-based system by 2014 at the busiest airports, and nationwide by 2020. The new system, known as NextGen, would cost the FAA about $22 billion through 2025, while airlines would spend about $20 billion to upgrade their airplanes' computer systems.
With the numbers of airline passengers growing, the new air-traffic system is expected in the long term to increase safety, save airlines money, reduce delays and cut down on pollution because pilots will be able to fly more direct routes.
Senate Democrats have scheduled a conference call for Monday afternoon on the bill.
The biggest remaining issues include the addition of 16 long-distance slots at Reagan National Airport.
Virginia Sens. Jim Webb (D) and Mark Warner (D) are opposed to adding any additional long-distance slots at the airport because of concerns that the larger planes needed to fly coast-to-coast would create more noise.
Western lawmakers have pushed for expansion of the airport’s so-called perimeter rule of 1,250 miles. If eased, the airport could see, for the first time, nonstop flights to cities such as Los Angeles, San Francisco, Salt Lake City and Phoenix.
There's also the issue of the Passenger Facility Charge (PFC), which the Senate bill held flat while the House-passed bill included a $3 increase from the cap of the current $4.50 level.
Rockefeller predicted that the PFC either won't change or could increase by $1.
Several groups are opposed to increasing the PFC, including the Air Transport Association calling it a "tax" on airline passengers.
A union issue with FedEx and UPS is still being worked out.
Rockefeller expects to hear from former Sen. Byron Dorgan (D-N.D.), with whom he worked for several years on the measure. Dorgan landed a job off Capitol Hill and said he would like do what he can to finally get the bill passed.
On the House side, House Transportation and Infrastructure Committee Chairman John Mica (R-Fla.) also has made passing the bill a priority this year.
The Aircraft Owners and Pilots Association (AOPA) is backing the reauthorization and is opposed to including any user fees.
On Jan. 21, 116 House lawmakers sent a letter to President Obama asking him to leave user fees out of his fiscal 2012 budget.
"AOPA is pleased to see the importance Congress is placing on long-term FAA funding," said Lorraine Howerton, AOPA vice president of legislative affairs. "The FAA has been operating on short-term funding extensions for several years, but it is critical that the agency receive long-term funding in order to support several key initiatives for the aviation industry, including modernizing the air traffic control system under NextGen."