January 14, 2020 By Dan Namowitz
GPS reception may be unavailable or unreliable over a large portion of the southeastern states and the Caribbean during offshore military exercises scheduled between January 16 and 24.
Graphic depicting area of GPS interference testing. Courtesy of the FAA.
The FAA has posted a flight advisory for the exercises that will require jamming of GPS signals for periods of several hours each day of the event. Navigation guidance, ADS-B, and other services associated with GPS could be affected for up to 400 nautical miles at Flight Level 400, down to a radius of 180 nm at 50 feet above the ground.
The flight advisory encourages pilots to report any GPS anomalies they encounter. Reports may be submitted using thisonline form
AOPA reported on a similar event in the southeastern United States in 2019.
AOPA is aware of hundreds of reports of interference to aircraft during events around the country for which notices to airmen were issued, and we consider the risks to GA aircraft highly concerning.
In one example, an aircraft lost navigation capability and did not regain it until after landing. Other reports have highlighted aircraft veering off course and heading toward active military airspace—and the wide range of reports makes it clear that interference affects aircraft differently. In some cases, recovery from signal interference may not occur until well after the aircraft exits the jammed area.
In a January 2019 AOPA survey, more than 64 percent of 1,239 pilots who responded noted concern about the impact of interference on their use of GPS and ADS-B.
AOPA continues to advocate for officials to place more focus on efforts to address the well-documented safety concerns raised by such events.
Associate Editor Web
Associate Editor Web Dan Namowitz has been writing for AOPA in a variety of capacities since 1991. He has been a flight instructor since 1990 and is a 30-year AOPA member.