More than two dozen US lawmakers want the FAA to stop running its new artificial-intelligence traffic tool at Reagan National, Washington Dulles and Baltimore/Washington International until the agency hands over safety testing records and explains how it trained the people overseeing the system.

The demand lands three weeks after the September 21 launch of limited SMART operations — Strategic Management of Airspace, Routes and Trajectories — the FAA's first AI-assisted congestion forecasting tool at the three Washington-area airports.

Representative April McClain Delaney, a Maryland Democrat, confirmed the congressional letter has gone to Transportation Secretary Sean Duffy and FAA Administrator Bryan Bedford. She and her co-signers say they have seen no safety evaluation or testing reports, and no evidence of training programs for aviation safety personnel.

"I'm calling on the FAA to pause this rollout, show us the safety testing, and explain who is accountable when something goes wrong," McClain Delaney said.

What does SMART actually do?

The system pulls together roughly 200 data streams — weather, flight paths, traffic demand and controller staffing among them — and forecasts congestion before delays cascade. It then suggests scheduling changes: route adjustments, shifted departure times, earlier interventions by traffic managers.

The FAA is firm on one boundary. SMART does not replace air traffic controllers. Agency staff review every recommendation, and local air traffic control leaders can accept or reject each one.

San Francisco-based Air Space Intelligence is building SMART alongside a replacement for the FAA's traffic flow management software. The agency pitched both tools as a way to help airlines and traffic managers act earlier, cut delays and squeeze more capacity out of existing airspace.

What are the lawmakers asking for?

The letter's requests go beyond testing documents:

• Results of SMART testing under severe weather and equipment outages
• Records of consultation with airport authorities, airlines and aviation safety workers
• The methodology for assessing the initial 90-day evaluation
• The conditions that must be met before nationwide expansion
• A clear answer on accountability if a SMART recommendation contributes to a safety incident

That last question is the sharpest. A tool that only advises still shapes controller decisions, and the lawmakers want to know who answers if an advised schedule change plays into an incident.

Co-leaders on the letter include Representatives Alexandria Ocasio-Cortez, Don Beyer, Kweisi Mfume, Suhas Subramanyam and Sarah Elfreth.

Where do the airlines stand?

Carriers were not unified going in. Airline officials raised concerns before launch about how SMART would fit into their operations — concerns the FAA defused by clarifying the tool would start with a limited role.

By the September 21 rollout date, executives at United, Delta, American and Southwest had publicly welcomed the initiative. Delta CEO Ed Bastian said the airline supports SMART. American CEO Robert Isom endorsed it too, but stressed careful implementation — the same caution now echoing from Capitol Hill.

What happens next?

When the FAA launched the system in September, it announced plans for gradual expansion beyond the Washington area. That timeline now depends on two things the agency controls: the results of its 90-day evaluation, and how completely it answers Duffy's and Bedford's mail. The pause request is not binding, but a congressional demand for safety records in the middle of an evaluation period gives the agency a reason to show its work before SMART touches another airport.