U.S. Navy MH-60S Seahawk pilots, assigned to the Helicopter Sea Combat Squadron 25, wait to be refueled by a helicopter expedient refuel system (HERS) during exercise COPE NORTH 2018 at Tinian, U.S. Commonwealth of the Northern Mariana Islands, Feb. 26. A HERS is a deployable fueling system capable of storing 3,000 gallons of fuel. (U.S. Air Force photo by Airman 1st Class Juan Torres Chardon)