- [metal clinking] [upbeat techno music]

- [Narrator] The U.S. military is staging widespread G.P.S. jamming events over three weeks as part of Red Flag, the multi-part, multi-national air war-games held over the Western United States out of Nellis Air Force Base in Nevada. Red Flag 18-1, the first round of this year's exercises, is the largest ever, with participants from the U.S. Air Force, Navy, Marine Corps, and the Australian and British Royal Air Forces. D.O.D. had advised the Federal Aviation Administration that the exercises will affect G.P.S. navigation over almost the entire Western United States overnight, from 11pm to 2am, Eastern time. G.P.S. jamming is intended to put pilots under combat conditions that challenge their reliance on the satellite navigation system. Red Flag's focus this year is on strike packages, as the Air Force puts it. Strike missions consisting of bombing and standoff missile attacks, fly-over hostile territory to attack targets, and are most likely to be affected by G.P.S. jamming by an adversary. Practically everything that the United States and allied militaries fly relies greatly on G.P.S. And even many weapon systems use it for guidance. But G.P.S. is particularly prone to jamming or manipulation, thanks to the relatively low power of G.P.S. satellite signals. North Korea frequently jams G.P.S. signals along its border affecting even commercial air traffic into Seoul. In this case, the jamming will be provided by U.S. military electronic warfare aircraft such as the Bowing EF-18 Growler, and the Lockheed EC-130H Compass Call. So if you're out driving late at night anywhere between Vegas, Los Angeles, and Seattle over the next few weeks, and you suddenly can't get a G.P.S. fix, look to the skies.