FAA Advises Pilots on GPS Problems as Air Force Training Jams Signals

As reported by Alaska Public Media: The Air Force is jamming Global Positioning System signals periodically around military airfields in Alaska during Red Flag training exercises now under way in and around Eielson Air Force Base. Officials say the GPS interference testing could affect other devices that rely on GPS.

The Federal Aviation Administration is advising pilots flying around Eielson Air Force Base, Fort Greely and Joint Base Elmendorf-Richardson over the next few days to expect unreliable or unavailable signals for their aircraft’s GPS set.

Air Force Lt. Col. Allen Knapp says it’s being done to prepare Air Force pilots to operate in environments in which GPS is not available.

“In a modern contested environments, most of the modern battlefields that our will face, the reception of GPS is definitely not guaranteed,” Knapp said. “It’s something that is going to be up for grabs. And it helps to have our airmen experience GPS being denied here in a training environment, like Red Flag, prior to an actual engagement where they lose their GPS reception.”

The FAA has issued several advisories in recent days informing pilots about the periodic GPS interference testing around the military airfields over the next 10 days, during Red Flag.

The agency says pilots may experience GPS problems at different times and at different altitudes. But the F-A-A says pilots should expect anomalies anywhere within 365 nautical miles from Fort Greely, up to 40,000 feet. Knapp says pilots should also expect GPS anomalies today through Friday within 150 nautical miles of Eielson, at 40,000 feet; and within 120 miles of JBER, at 40,000.

This week’s GPS interference testing around Eielson and Greely is being conducted from mid-morning to around 12:30 p.m. and again from 4:15 to 5:15 p.m. daily. The schedule will vary beginning this weekend, with once-a-day testing scheduled for some days.

FAA officials ask pilots to report all GPS anomalies they encounter during the testing to the agency’s Anchorage Center to help them measure the extent of the problem.

Knapp says the Air Force jamming should not affect cellphones or other mobile devices. But he says motorists will encounter problems with their vehicle’s GPS sets is they’re near any of the three military air bases during the tests.

He says members of the public may also notice problems when using devices that rely on GPS for time calibration.

“I can’t tell you that we categorically we will not affect anything else,” Knapp said. “More and more, technologies are drawing upon that (GPS) and using that for the services they provide.”

The FAA says additional Notices to Airmen will be issued throughout the testing period to keep pilots apprised of any changes in plans for the testing.