Direct Fire Marine Corps Sgt. George Hamil observes as Sgt. Zachary Zimberg uses direct fire to assault targets during Amphibious Squadron-Marine Expeditionary Unit Integration over the Pacific Ocean, April 5, 2017. Zimberg is a crew chief assigned to Marine Medium Tiltrotor Squadron 161, 15th Marine Expeditionary Unit. The exercise aims to improve skills and tactics to enhance the unit's operational abilities. Marine Corps photo by Cpl. Nathaniel S. McAllister SHARE: Download: Full Size (1.18 MB) Credit: Lance Cpl. Nathan McAllister VIRIN: 170405-M-FJ661-0023C.JPG Photo Gallery