Deputy Defense Secretary Bob Work boards a U.S. Army UH-60 Black Hawk helicopter at the Pentagon as he departs for Naval Surface Warfare Center Dahlgren Division in Dahlgren, Va., April 30, 2015. Work was visiting the research and development center for updates on their innovations with existing and new platforms and equipment. Deputy Defense Secretary Bob Work boards a U.S. Army UH-60 Black Hawk helicopter at the Pentagon as he departs for Naval Surface Warfare Center Dahlgren Division in Dahlgren, Va., April 30, 2015. Work was visiting the research and development center for updates on their innovations with existing and new platforms and equipment. SHARE: Download: Full Size (1.47 MB) Tags: Photo Essays Credit: VIRIN: 868776-K-XOG14-349.jpg Photo Gallery