Incoming Chief Defense Secretary Ash Carter administers the oath of office to Air Force Gen. Joseph L. Lengyel, incoming chief of the National Guard Bureau, during a change-of-command ceremony at the Pentagon, Aug. 3, 2016. Lengyel assumed command from retired Army Gen. Frank J. Grass. DoD photo by Navy Petty Officer 1st Class Tim D. Godbee SHARE: Download: Full Size (0.9 MB) Credit: MC1 Tim D. Godbee VIRIN: 160803-D-SK590-318C.JPG Photo Gallery