U.S. Air National Guard Master Sgt. Travis Metcalf, Airman 1st Class Matt Niles and Senior Airman Chris Countryman all crew chiefs with the 185th Air Refueling Wing, Iowa Air National Guard, lower the boom on an Air Force KC-135 Stratotanker, November 3, 2015. The boom is being lowered while in the fuel cell hangar in Sioux City, Iowa in preparation for washing as part of a scheduled 180 day aircraft wash. (U.S. Air National Guard photo by: Master Sgt. Vincent De Groot 185ARW PA/released)