GAO: FAA’s Air-Traffic Modernization Lacks Full Cost Estimate and Master Schedule

A new watchdog report says the Federal Aviation Administration’s accelerated overhaul of the U.S. air traffic control system is moving ahead without two basic management tools: a credible estimate of what the entire effort will cost and a unified schedule showing how the work fits together.

In a report published Monday, the Government Accountability Office said those gaps put the FAA’s Brand New Air Traffic Control System, or BNATCS, at higher risk of cost overruns, delays and continued dependence on aging equipment used to manage up to 45,000 flights a day. GAO warned that if the problems persist, the agency could be forced to rely longer on outdated systems prone to failure, adding to flight delays and safety incidents.

The report, GAO-26-107992, examines a modernization program the Transportation Department announced in May 2025 as an accelerated response to longstanding technology problems and a string of operational failures, including telecommunications outages tied to old copper lines in spring 2025 and near-collision incidents earlier that year.

Congress appropriated about $12.5 billion for BNATCS in July 2025, with the enacted amount set at $12.52 billion in Public Law 119-21, Section 40003. The FAA is using most of that money for the program’s first phase, according to GAO.

BNATCS is divided into two phases. Phase 1 covers modernization of communications, surveillance, weather, training and related systems, and is supposed to be fully completed by Dec. 31, 2028. Phase 2 would develop new automation systems to track aircraft and optimize traffic. The FAA told GAO that phase is expected to cost about $10.2 billion, excluding facilities, but the agency has not set a start date or completion date.

GAO said the FAA still has not built a reliable picture of the full cost of the overall program. “FAA has not developed a comprehensive and well-documented lifecycle cost estimate for BNATCS,” the report said. Auditors said the agency provided high-level Phase 1 cost estimates in June 2026 but could not provide the underlying analysis behind those figures.

The estimate also leaves out major categories of spending. According to GAO, it does not include government costs, most Phase 1 operations costs or any Phase 2 costs. Without a full lifecycle estimate, GAO said, agency leaders and Congress lack a dependable basis for judging affordability and future funding needs.

The schedule problems are similarly basic. GAO found that the FAA had not developed an integrated master schedule for Phase 1 — a detailed, programwide timeline used to coordinate complex projects, track dependencies and manage delays. Instead, the agency had 11,389 individual project schedules that were not integrated.

That matters because separate schedules can mask conflicts and inefficiencies. GAO said projects can end up being planned at the same facilities without being optimized to reduce disruption to air traffic control operations.

The watchdog said the weaknesses echo a familiar pattern. The FAA has a long history of modernization efforts that ran over budget, slipped behind schedule or fell short of performance goals. In September 2024, GAO reported that more than 75% of the FAA’s 138 air traffic control systems were unsustainable or potentially unsustainable.

The report does not say BNATCS has made no progress. As of May 2026, the FAA reported replacing 2,560 of 5,170 aging copper telecommunications lines with fiber-optic cable, one of the most visible elements of the first phase.

Still, GAO said the program is advancing faster than the agency’s planning discipline. It made two recommendations: that the FAA prioritize developing a reliable lifecycle cost estimate for BNATCS and create a detailed integrated master schedule for Phase 1. GAO listed both recommendations as open.

The Department of Transportation, which oversees the FAA, partially concurred with the recommendations in writing, GAO said. The watchdog maintained both are necessary.

The push to modernize has carried a sense of urgency. In announcing the program’s prime integrator in December 2025, Transportation Secretary Sean P. Duffy said, “We are thrilled to be working with Peraton because they share President Trump’s drive to modernize our skies safely at record speed.”

But GAO’s message in Monday’s report was that speed alone is not enough: The FAA is moving quickly on a high-stakes overhaul, while the basic cost and scheduling controls needed to manage it are still not in place.