Pentagon Will Track D.C. Helicopter Noise
Few practical options exist for mitigating helicopter noise in the Washington, D.C. area.
The U.S. Park Police flying over the Potomac River.

The Pentagon will be charged with tracking helicopter noise in the Washington, D.C. area under provisions of the recently enacted National Defense Authorization Act. The provision in the massive $740 billion legislation was inserted at the behest of several D.C.-area congressmen who have long lamented the steady rotor din over the nation’s capital and surrounding suburbs. But what all this data will actually accomplish remains to be seen. As in the Los Angeles Basin, the competing pressures of crowded airspace and the aviation needs of public safety and law enforcement limit practical—and safe—options. 


The amount of helicopter traffic over the D.C. area is substantial, according to data recently released in a Government Accountability Office (GAO) report that details the scope of helicopter activity there. The GAO found that there were 88,000 helicopter flights there between 2017-2019 by 50 separate operators. All flights were conducted within 30 miles of Washington Reagan International Airport—an area with three large hub airports, 11 regional airports, and 55 heliports. The majority of these flights—some 80 percent—are conducted by the military, law enforcement, and air ambulance providers. Locally-based fleets serving these operators include: 


The Federal Bureau of Investigation—six Sikorsky UH-60Ms and three Bell 429s. The FBI uses their aircraft primarily to shuttle personnel between its D.C. headquarters and its academy in Quantico.


The U.S. Park Police—two Bell 412Eps and one Bell 206L3—based at its Eagles Nest facility in D.C.


The USAF 1stHelicopter Squadron—21 Bell UH-1s stationed at Joint Base Andrews.


The Army 12th Aviation Battalion—34 Sikorsky UH-60s based at Davison Army Airfield, Fort Belvoir, Virginia. Also based there, three more UH-60s and six Airbus UH-72A Lakotas used by the Aviation Branch of the Army National Guard.


U.S. Coast Guard—three Airbus MH-65Ds based at Reagan National Airport.


Marine Helicopter Squadron One (HMX-1) stationed at bases including Marine Corps Air Facility Quantico, Virginia, the Pentagon, the White House, the Naval Observatory, and Joint Base Anacostia-Bolling—12 Bell Boeing MV-22s and 11 Sikorsky VH- 3Ds, one Sikorsky UH-3D, one Sikorsky UH-60N, and eight Sikorsky VH-60Ns.


Fairfax County (Virginia) police—two Bell 429s.


Maryland State Police—10 Leonardo AW139s.


D.C. Metro Police—two Airbus AS350s.


Prince George’s County (Maryland) Police—four MD520Ns.


Virginia State Police—four Bell 407s, one Bell 412, two Airbus EC-145s, and one Bell 412. 


The GAO study enumerated a variety of factors in the growth of the helicopter noise problem in the D.C. area, what operators already have done to mitigate noise, and the difficulties with any further reduction due to D.C.’s highly-restricted and complex airspace. For example, the Pentagon tightened restrictions as to who was authorized to use its heliport, thereby chopping the number of flights originating there from 226 in 2016 to 124 in 2019. Other operators have told crews to refrain from making tight turns and other maneuvers that exacerbate helicopter noise. In general, helicopter flights in the region adhere to an established network of 25 fixed routes in place since the 1980s that overfly rivers and major freeways to mitigate aircraft noise. But the nature of D.C.’s highly secure and regulated airspace often works at cross purposes with that goal. 


This is particularly true in the airspace proximate to Reagan National, where the GAO notes, the “FAA further limits the maximum altitudes for helicopters where helicopter routes overlap with commercial passenger airplane operations to ensure the safety of all aircraft. As a result, helicopters in these areas may fly as low as 200 feet above mean sea level. Elsewhere, the helicopter route structure generally establishes maximum altitudes between 1,000 and 1,300 feet above mean sea level throughout most of the D.C. area. Because FAA’s maximum helicopter altitudes are established relative to mean sea level, the maximum posted altitudes relative to objects on the ground may be lower or higher, depending on local geography, buildings, or obstructions.”


It is also unlikely that area operators will be able to reduce their volume of night operations that account for 23 percent of all flights and are a disproportionate source of complaints. The GAO found that crime-riddled Prince George’s County—notorious for leading the nation in police shootings—conducted 90 percent of its flight operations at night. Air Methods reported that 50 percent of its area air ambulance flights were at night. And military officials told the GAO that certain night operations in the region—particularly training, night vision goggle proficiency, and aircraft intercept—were essential. They also noted that the D.C. area’s unabated growth—from a population of 2.77 million in 1980 to 5.38 million in 2020—means that residential housing is being built closer to rotorcraft bases. 


Overall, other than measuring helicopter noise, not much can be done. Writing to the GAO in December 2020, DOT deputy assistant secretary for administration Keith Washington warned, “Significant reductions in helicopter noise in the National Capital Region will be challenging since the majority of operations are military, law enforcement, and medevac service providers.”