Transportation Secretary Sean Duffy and airline industry leaders are asking Congress to approve $30 billion in new funding to complete the modernization of US air traffic control, on top of the $12.5 billion already deployed under the administration's tax legislation.

The vehicle is the Modern Skies Act, introduced by Senator Eric Schmitt, Republican of Missouri. The bill would allocate the money in three equal blocks: $10 billion for a reliable digital architecture, $10 billion to overhaul outdated physical infrastructure, and $10 billion to build new airport capacity.

The request comes as the Department of Transportation begins deploying the first tranche of money. According to the department, the $12.5 billion secured in the Working Families Tax Cut Act is funding upgraded telecommunications lines, new radios and radars, and the transition to electronic flight strips. Officials say all 13 modernization workstreams are on track and the deployment should be complete by the end of 2028.

A central element of that effort went live last week. SMART, a new air traffic control management tool, centralizes 200 data streams into a single system that produces recommendations intended to unlock airspace capacity and modernize flight scheduling. Its AI-powered engine visualizes flight paths and airspace capacity and forecasts weather or congestion before delays occur.

The digital portion of the Modern Skies Act would deepen that investment. Of the $10 billion, $7.2 billion would update the digital safety tools controllers use to keep aircraft separated, $2 billion would overhaul the data architecture to add bandwidth, cybersecurity and resiliency, $600 million would fully deploy SMART and the FMDS flow management system, and $300 million would consolidate terminal air traffic control facilities. The bill also funds upgrades to the controller separation tools known as CAP, a more resilient telecommunications backbone called FENS, and expanded air traffic flow management through FMDS.

The infrastructure tranche addresses a backlog the FAA has quantified starkly: at current funding levels, replacing FAA-owned aging control towers would take 300 years. The $10 billion includes $2 billion to construct, replace and improve FAA-owned towers, $3 billion for Airport Improvement Program discretionary grants and $5 billion for Airport Terminal Program discretionary grants.

The remaining $10 billion would establish a new pilot grant program for terminals, capacity upgrades and cargo expansion at what the department calls transitional hubs — airports serving between 5 million and 25 million passengers annually that lack access to capital. The stated rationale is network efficiency: by absorbing connecting traffic, these hubs would relieve congestion at major airports and anchor regional supply chains.

The bill also includes transfer authority for the $12.5 billion already appropriated, giving the FAA flexibility to continue rapid equipment deployment toward the 2028 target.

Backers argue the combined investment is necessary because current funding, while addressing safety and efficiency gaps, cannot fully resolve the constraints on US air travel. The department projects the spending will generate trillions in economic activity, a claim that will be tested against congressional appropriations arithmetic as the legislation moves forward.

For airlines, the stakes are concrete: SMART and FMDS promise measurable airspace capacity gains, while airport construction dollars determine where additional flights can actually be scheduled. Congress has not yet scheduled action on the bill.