THREE LEADERS Defense Secretary Chuck Hagel, left, and Deputy Defense Secretary Ash Carter, center, sit with Air Force Secretary Michael B. Donley during his farewell ceremony on Joint Base Andrews, Md., June 21, 2013. Donley served as the 22nd and longest serving Air Force secretary. SHARE IMAGE: Download Image: Full Size (0.05 MB) Photo By: VIRIN: 056505-Y-RFQ53-143.jpg Photo Gallery