The Federal Aviation Administration is warning pilots that GPS testing could leave the global-positioning signals “unreliable or unavailable” across much of the West for six days in June.

The testing that began Tuesday based in Southern California could hurt flight controls for a specific kind of business jet, the FAA warned. But the testing shouldn’t affect commercial airliners, according to experts.

“I think there are safeguards in place,” said John Cox, a former airline pilot and now president of consulting firm Safety Operating Systems.

Pilots and air-traffic controllers will keep an eye on planes within the warning area for any flight abnormalities, he said. But if pilots hear by radio about strange GPS signals in a given area, they could adjust altitude or navigate around the problem as if it were bad weather, he said.

“You route around it as if it were thunderstorms,” Cox said.

The testing centered at Naval Air Warfare Center Weapons Division based in China Lake, Calif., could affect aircraft at least 50 feet off the ground within hundreds of miles of the base to as high as 40,000 feet above sea level nearly 550 miles away. The affected area is the shape of an upside-down layer cake, with the largest layer 40,000 feet high spanning California and Nevada, and stretching across much of Oregon, Idaho, Utah and Arizona.

Read More- USA Today

Image courtesy of