Afuel gauge is seen in a CC-150 Polaris refueling tanker as Royal Canadian Air Force Airmen assigned to the 437th Transport Squadron based out of Canadian Forces Base Trenton, Canada, perform refueling operations in training airspace over Alaska during the Red Flag-Alaska 19-3 exercise, Aug. 15, 2019. Red Flag-Alaska, a series of Pacific Air Forces commander-directed field training exercises for U.S. forces, provides joint offensive counter-air, interdiction, close air support, and large force employment training in a simulated combat environment. (U.S. Air Force photo/Justin Connaher). Original public domain image from Flickr