May Result In Unreliable GPS Signals

The FAA has posted a Flight Advisory alerting pilots flying in much of the Southeast portion of the U.S. that GPS interference testing will take place for twelve days beginning December 1. The agency says the testing may result in unreliable or unavailable GPS signal.

The tests will be centered off the coast of Jacksonville, FL at 302000N/0800000W or the CRG VOR 89.9 degree radial at 78.2NM. According to the advisory, each event during the scheduled dates may last up to 45 minutes followed by 15 minutes off, and More than one event may occur during the requested times.

The testing is scheduled between December 1st and 12th between 2100-0245Z (1600-2145 EST). During testing, the GPS signal may be unreliable or unavailable within a 300NM circle centered at 302000N/0800000W or the CRG VOR 89.9 degree radial at 78.2NM at FL400 and above, decreasing in area with decrease in altitude to 255 NM at FL250, 191 NMR at 10,000 FT MSL, 147 NM at 4,000 FT AGL and 73 NM at 50 FT AGL.

Pilots are strongly encouraged to report anomalies during testing to the appropriate ARTCC to assist in the determination of the extent of GPS degradation during tests. The NOTAMs discussed in this advisory may change with little or no notice. Pilots are advised to check NOTAMs frequently for possible changes prior to operations in the area. NOTAMs will be published at least 24 hours in advance of any GPS tests.

FMI: www.faa.gov