The FAA has issued a flight advisory for potentially unreliable GPS signals in the vicinity of Kodiak, Alaska on June 13, 15 and 16.
During testing, the GPS signal may be unreliable or unavailable within a 259-nautical-mile radius centered at 575802N/1480116W or the ODK VOR 83.4-degree radial at 138.1 nm at Flight Level 400 and above, decreasing in area with decrease in altitude to 213-nm radius at Flight Level 250, 148 nm-radius at 10,000 feet msl, 105 nm-radius at 4,000 feet agl and 40 nm-radius at 50 feet agl.
Pilots are encouraged to report anomalies to the appropriate air route traffic control center to help determine the extent of signal degradation. Please share your reports with AOPA.
Notams will be published at least 24 hours in advance of tests, but may change with little or no notice. Pilots are encouraged to check notams frequently for changes to operations in the area. Tests will be during any period within the stated times, the FAA said.
The testing schedule is set for 1800Z to 2100Z daily on June 13, June 15, and June 16.