U.S. Sen. Maria Cantwell (D-Washington), ranking member of the Senate  Commerce Committee, wrote a letter on March 7 voicing concerns about the Department of Defense’s (DOD) use of an exemption that allows helicopters to operate in the National Capital Region without automatic dependent surveillance-broadcast (ADS-B) Out activated. The senator’s concerns stem from the January 2025 fatal crash near Washington, D.C., in which a U.S. Army Sikorsky Black Hawk helicopter was operating without ADS-B Out during a routine check ride.

In the letter to Defense Secretary Pete Hegseth, Cantwell pointed to a 2019 exemption issued by the previous Trump Administration allowing federal, state, and local government entities, including the DOD, to operate certain aircraft without ADS-B Out for “sensitive operations.” While the FAA cautioned that this exemption should not be routinely used, Cantwell expressed concern that the DOD has taken advantage of this rule more broadly than intended.

The senator noted a 2023 DOD statement that both the Army Aviation Brigade at Fort Belvoir and Marine Helicopter Squadron One operate all missions without ADS-B Out activated. This contradicts the FAA’s guidance that non-transmission of ADS-B should be rare, she maintained. “It is not credible to assert that each of the several thousand helicopter flights operated annually in the National Capital Region is sufficiently sensitive to merit a blanket exemption,” Cantwell wrote.

Cantwell referenced reports of Army and Air Force aircraft flying without ADS-B Out for non-sensitive events, such as honorary funeral flyovers at Arlington Cemetery and recruitment events at Howard University. These activities, she argued, do not qualify as “sensitive” operations.

Cantwell’s letter outlined several questions for the DOD, including how the agency determines which flights qualify for the ADS-B Out exemption, how often the DOD has used the exemption since 2019, and whether any assessments or audits have been conducted to ensure proper usage. The senator has called for greater transparency and review of the DOD’s ADS-B Out practices to enhance aviation safety in the region.

This inquiry comes in the wake of a tragic January collision between the Black Hawk and a commercial PSA CRJ700 regional flight, operating as American Airlines Flight 5342, that killed 67 people, following the NTSB’s confirmation that the Black Hawk helicopter was not transmitting ADS-B Out.