Sgt. Brian McCown (right), an M1 Abrams Main Battle

Sgt. Brian McCown (right), an M1 Abrams Main Battle Tank crewman with Headquarters and Headquarters Company, 1st “Vanguard” Battalion, 18th Infantry Regiment, 2nd Advise and Assist Brigade, 1st Infantry Division, United States Division –Center and a Eureka, Mo. native, teaches Pfc. Frankie Busby, an M1 Abrams crewman and a Linton, Ind. native, the responsibilities of an electronic warfare non-commissioned officer June 9, 2011 at Camp Taji, Iraq. McCown is the longest-serving member of the Vanguard Battalion and has deployed with the unit three times since 2004. (Photo by Spc. William A. Joeckel)