Consultants propose RNAV route tweaks to shift some National Airport flights over Potomac River to ease Fairfax overflights

Consultants presented a set of navigation‑procedure changes aimed at reducing aircraft overflights of Fairfax neighborhoods by shifting some traffic over the Potomac River and other less populated or compatible land uses.

Jim Allardyce, the Vionaire consultant leading the study, told the Land Use Policy Committee the project’s design philosophy prioritized routing over the center of the Potomac and over compatible land such as industrial areas, major highways and government land, while maximizing altitude and increasing track variability to avoid disproportionate impacts on any single jurisdiction. "We believe we can map those designs back to this design philosophy," he said during the June 17 briefing.

The study focuses on the airport’s south‑of‑airport study area. For westbound departures that currently turn inland, staff proposed revised westbound tracks that would keep roughly 43 percent of those west‑bound departures over the river rather than over neighborhoods; the remainder would continue toward the northwest. On nearby arrivals, an optimized profile descent would raise altitudes over some populated places — Allardyce cited moving the glide path from about 2,500 feet to 3,000 feet in parts of the approach corridor.

Consultants emphasized the changes provide temporal rather than permanent relief: the shifts benefit different neighborhoods at different times depending on whether the airport is operating in a north or south flow. "When the aircraft come back over land, they come back over very sparsely populated land and government land," Allardyce said, describing the intended distribution of impacts.

Next steps and timing Staff said they are closing the public‑comment period, expect a community working group (CWG) briefing in late July and anticipate a CWG vote to forward the recommendations to the FAA. Allardyce told the committee that informal TRACON controller conversations had occurred but that formal FAA approval would follow the roundtable process. Staff cautioned that FAA procedure changes can take time: they reported the FAA advised an implementation horizon of roughly four years, citing reduced procedure workload capacity in the FAA’s procedure offices.

Tools and short‑term options The consultant and staff discussed shorter‑term options such as a Fly Quiet program — a voluntary airport‑level initiative that collates flight and noise data and seeks negotiated operational changes with airlines — and the use of noise monitoring systems. Allardyce described a virtual noise‑monitoring platform that can model noise across a wide grid and estimated ongoing service and customization costs in the area could be on the order of $120,000 per year.

Board reactions and outstanding questions Supervisors praised the technical work and asked for more engagement with adjacent jurisdictions and military landowners (Fort Belvoir was noted as not having been specifically contacted). Committee members also pressed for outreach materials the county can share with residents, and for elected officials to be prepared to advocate to the FAA once the CWG forwards recommendations. Several members asked staff to further detail the safety and efficiency arguments likely to persuade FAA technical reviewers.

The committee did not vote on a policy at the meeting; staff and the project team will continue public engagement and return with further updates as the CWG and FAA processes proceed.