Aircraft Noise: Military Helicopter Operators Should Improve Outreach to Affected Communities in the D.C. Area

What GAO Found

According to Federal Aviation Administration (FAA) data for 2020 through 2024, helicopter operators cumulatively averaged over 32,000 flights and 20,000 flight hours annually in the Washington, D.C. area (D.C. area). During this 5-year period, operators conducted an average of 91 flights per day, ranging from one to 202 flights. Military, air medical, and state and local law enforcement operators accounted for most helicopter flights and flight hours. Military operators include the Department of Defense's (DOD) Air Force, Army, D.C. Army National Guard, and Marine Corps, and Department of Homeland Security's (DHS) Coast Guard.

FAA-Reported Helicopter Flights and Flight Hours in the Washington, D.C. Area by Operator Type, 2020-2024

Source: GAO analysis of Federal Aviation Administration (FAA) data. | GAO-26-107758

Note: In this table, the Washington, D.C. area comprises the area within 30 nautical miles of Ronald Reagan Washington National Airport. For more details, see table 1 in GAO-26-107758.

According to FAA, it has taken steps to address helicopter noise in the D.C. area, including collecting and sharing noise complaint data. For example, FAA collects complaints through a centralized system and posts summaries of D.C.-area helicopter noise complaints on its website. Air medical, local law enforcement, and military helicopter operators GAO spoke with have also taken steps to reduce noise impacts. These steps include flying along designated helicopter routes, avoiding certain residential areas, and conducting training flights outside the D.C. area. However, military operators have not engaged in continuous awareness and outreach programs to communities affected by helicopter noise, as required by DOD's Operational Noise Program. Helicopter route changes near Ronald Reagan Washington National Airport after the January 2025 midair collision may heighten the need for military operators to engage in community outreach, because some new areas will experience noise impacts. By conducting additional outreach, military operators could help these communities better understand the purposes of helicopter flights and their efforts to reduce noise.

Selected operators said they use drones infrequently for their D.C.-area operations. As such, drones have little effect on overall aircraft noise. GAO spoke with three local law enforcement operators that use drones, and they said drones are not a substitute for helicopters for their missions. Military and air medical operators told GAO they cannot use drones in the D.C. area due to the nature of their operations. In addition, selected stakeholders said the potential effects that electric vertical takeoff and landing aircraft may have on noise are unclear, in part because none are currently in operation, and operators do not have immediate plans to use them in the D.C. area.

Why GAO Did This Study

Helicopter noise is an ongoing concern for some D.C.-area residents. The D.C. area is unique among areas with high concentrations of helicopter activity due to its highly restricted and constrained airspace and the presence of many federal agencies and military installations. Studies have suggested that aircraft noise exposure can be annoying, disturb sleep, and increase the risk of more serious medical issues.

The FAA Reauthorization Act of 2024 includes a provision for GAO to report on reducing rotorcraft noise in the D.C. area. This report examines, in the D.C. area, (1) the extent to which helicopter operations are conducted and for what purposes, (2) the extent to which FAA and selected operators have addressed helicopter noise, and (3) the views of selected operators and stakeholders on how the use of drones and electric vertical takeoff and landing aircraft may affect helicopter noise.

GAO reviewed FAA regulations, relevant laws, DOD and DHS policies, and relevant literature, and analyzed FAA and military operators' helicopter flight data for 2020 through 2024. GAO also interviewed FAA officials; 11 helicopter operators, selected based on the number of flights in the D.C. area; and seven stakeholders, selected based on experience with drone and electric vertical takeoff and landing aircraft noise.