https://www.popularmechanics.com/milita ... -red-flag/The U.S. military is worryingly dependent on GPS. Our global positioning satellites tell planes where they are, provide targeting info for smart weapons, and support communication and navigation systems. But in a war with a tech-advanced adversary—think China, Russia, or Iran—GPS could become a big liability because it could be jammed, spoofed, or outright destroyed.
Red Flag is a regular exercise that includes Allies...this exercise has British and Australian forces, all staging out of Nellis AFB outside Las Vegas...
Navigation, smart bombs, and a whole myriad of other equipment is GPS oriented...and it is pretty well known that the Chinese military has done extensive work on how to block or even take down GPS...
The Air Force won’t reveal how they will blackout the play area...The blackout won't be quite as precise as America's precision fighters, though. GPS could be knocked out for adjacent airspace as well, potentially disrupting airliners and private planes in portions of Nevada, California, Arizona, and Utah. Affected civilian aircraft will have to turn to other onboard radio or inertial navigation system (INS) or rely on air traffic control radar vectors.
This isn't the Air Force's first self-imposed blackout, having previously turned off GPS during Red Flag exercises in Alaska. The Air Force tells Popular Mechanics that there will be "little to no effect" for civilian aircraft. And yet the fact that there could be a disruption of civil GPS service in the continental U.S. shows the increasing importance of training for a GPS-less scenario.
The ethanol plants that I have visited just used straight corn, no cobs. 
