The FAA on June 23 published a notam that describes a large area encompassing much of the East Coast and Atlantic Ocean within which U.S. Navy activity could reduce the sensitivity of avionics that operate in the affected frequency range. Most ADS-B units installed in general aviation aircraft operate on 978 MHz, and should not be affected.
AOPA has worked with the FAA to coordinate advisories and give pilots as much advance notice as possible. No delays or traffic disruptions are expected within the areas affected by the military activity expected to occur intermittently over periods lasting up to 12 hours in a given day.
Anomalies affecting avionics are deemed “unlikely,” and pilots are advised that the military activity will not create false alerts on traffic collision avoidance systems (TCAS), and that any TCAS alert should be treated as valid. Pilots are asked to report any such anomalies to air traffic control, which will allow ATC to implement established mitigation protocols (such protocols have not been needed to date).
The June 23 notam was issued in very similar fashion to one posted in March, when similar military activity created a potential for reduced ADS-B sensitivity.
Pilots are asked to share any impacts experienced from a GPS interference event with AOPA.