U.S. Marine Corps Lance Cpl. Travis Stallings, a crew chief assigned to Marine Medium Tiltrotor Squadron (VMM) 166, Marine Aircraft Group 16, 3rd Marine Aircraft Wing, closes a hatch on an MV-22 Osprey tiltrotor aircraft for takeoff during Desert Scimitar 2015 (DS15) on Marine Corps Air Station Miramar, San Diego, Calif., April 10, 2015. DS15 is a combined arms exercise that allows units to maintain readiness and meet current and future real-world demands. (U.S. Marine Corps photo by Cpl. Darien J. Bjorndal, 3rd Marine Aircraft Wing/ Released)