The debate over how to best upgrade the air traffic control system has pitted airlines against each other.

A privatization effort fizzled last year in Congress, but the issue may take on a new shape if Trump’s administration takes a position and includes its own proposal as part of a plan for transportation infrastructure.

On one side of the debate is the lobbying group for major carriers, known as Airlines for America. Representing American, United, UPS, Southwest, JetBlue and others, the group is pushing to remove the air traffic control operation in the United States from the Federal Aviation Administration and turn it over to a non-profit entity.

On the other side has been Delta Air Lines, along with consumer groups that call privatization “an unprecedented giveaway to special interests in Washington.”

Atlanta-based Delta last year argued that privatization “is a bad idea,” saying it would be a distraction that would disrupt momentum and wouldn’t fix the problem.

Delta argued during last year's debate that the FAA is making steady progress on its multi-billion dollar air traffic control modernization project, known as NextGen. Former Delta CEO Richard Anderson was chairman of a NextGen advisory committee.

With Delta now led by Anderson’s successor, CEO Ed Bastian, the airline on Monday released a more neutral statement.

“Delta remains committed to working with the FAA and other aviation industry stakeholders to make U.S. airspace more efficient, with a goal of reducing delays, improving traffic flows and enhancing airline performance,” the company said.

The question of how to fund and structure the nation’s air traffic control system is a key issue as the FAA faces another Congressional fight over re-authorization, with its spending authority expiring Sept. 30.

A4A, as the airline lobbying group is known, says removing air traffic control from the FAA would make air traffic control less dependent on Congress for appropriations and less subject to political whims that led to sequestration and a government shutdown in recent years, hindering the FAA from long-term planning for NextGen.

NextGen’s main thrust is to shift the system to satellite-based navigation with digital communication, which can allow more direct routing and closer spacing between planes, boosting system capacity. Work on NextGen improvements started in 2007 and is expected to continue through around 2030.

“Progress on NextGen has been slow” because it’s “trapped in the politics of Washington, D.C.,” said Sharon Pinkerton, senior vice president of legislative and regulatory policy. She said $6 billion is sitting in the FAA aviation trust fund “when the system is really in need of modernization.”

Trump “obviously has an understanding that the system is woefully outdated, and I think that’s a good first step in trying to reach a resolution,” Pinkerton said.

Privatizing air traffic control fits into a broader “small-government” philosophy.

“Being part of the federal government is not very conducive to efficient results,” said Rui Neiva, a policy analyst at the Eno Center for Transportation, which released an updated report last week in favor of spinning off air traffic control from the FAA. Other governments have done so successfully, including Canada.

The National Air Traffic Controllers Association union last year supported a proposal to spin off air traffic control, saying it would “make safety the top priority,” ensure stable funding and protect the controller workforce.

Air traffic controllers union president Paul Rinaldi in a written statement emphasized the importance of a “stable, predictable funding stream” to ensure progress on NextGen continues and “is not undermined.”

But consumer groups that formed a group called Americans Against Air Traffic Privatization say “the true incentives behind privatizing our nation’s ATC system [are] corporate control at the exclusion of workers and taxpayers.”

Opponents also note that foreign examples of successful privately-run systems cited by supporters involve much smaller systems than the one controlling U.S. airspace.

A MASSIVE SYSTEM

U.S. air traffic control by the numbers:

7,000 aircraft in the sky at any given time

23,911 commercial flights a day

476 airport traffic control towers

14,000 air traffic controllers

19,299 airports

Source: Federal Aviation Administration

DOGFIGHT OVER ATC

The issue at a glance:

— Today, the Federal Aviation Administration runs the U.S. air traffic control system and employs controllers.

— The FAA is leading a massive, decades-long effort to modernize the air traffic control infrastructure, with a shift from ground-based radar to satellite-based navigation.

— Some airlines and others want to spin off air traffic control from the FAA into a non-profit entity funded with user fees. They say it would remove government budget constraints and the influence of politics that led to sequester and furloughs of controllers in recent years.

— Opponents say privatization could disrupt the FAA’s momentum on NextGen, and that it would amount to transferring a public good to corporate interests, with less room for government oversight.