Chet Hollingsworth, Air Mobility Command Museum tour guide, talks with Joint Base Lewis-McChord, Wash., honorary commanders and civic leaders by a B-17G Flying Fortress June 8, 2017 at the AMC Museum on Dover Air Force Base, Del. Hollingsworth answered questions from the group about the Sperry Ball Turret used by B-17 gunners. (U.S. Air Force photo by Roland Balik)