The Federal Aviation Administration released a flight advisory  last week concerning scheduled GPS interference testing based in the Big Delta area. From Aug. 11-24, GPS testing may result in unreliable or unavailable signals ranging outward from Big Delta to 365 nautical miles and up to 40,000 feet.
Centered at 634714N/1455152W or the BIG VOR 173 degree radial at 014NM, the tests will affect the surrounding area as follows:
Pilots are encouraged to report all GPS anomalies in the area during testing to Anchorage Center to assist in measuring the extent of signal degradation.
Notices to Airmen (NOTAMS) will be issued and updated throughout the testing period. Pilots flying through the area should check NOTAMS frequently as testing periods may change. The FAA advises that NOTAMS will be issued 24 hours in advance of all testing. The current scheduled times for the testing are as follows:
Aug. 11: 9:50 a.m. - 12:30 p.m.
Aug. 12-15: 4:15 p.m. - 5:15 p.m. and 9:50 a.m. - 12:30 p.m.
Aug. 16: 4:15 p.m. - 5:15 p.m.
Aug. 18: 9:50 a.m. - 12:30 p.m.
Aug. 19-21: 4:15 p.m. - 5:15 p.m. and 9:50 a.m. - 12:30 p.m.
Aug. 22: 4:15 p.m. - 5:15 p.m.
Update: The government agency conducting the testing is the Department of Defense, based in Fort Greeley. For more information, see this website .
Contact Colleen Mondor at firstname.lastname@example.org .