Marty Martinez, instructor for General Dynamics, instructs U.S. Air Force Airman 1st Class Nicholas Lafferty, left, Staff Sgt. Timothy Wertz, and Senior Airman Mike Walton, 920th Civil Engineering Squadron, Youngstown, Ohio, in simulated convoy operations war games using the U.S. Army's Virtual Battlespace Simulator 2 at Fort Hunter Liggett, Calif., May 19, 2011, in support of Global Medic 2011 and Warrior 91 11-01. Global Medic is a joint Reserve field training exercise for theater aeromedical evacuation system and ground medical components designed to replicate all aspects of combat medical service support.