glossary 11b infantryman 1sg first sergeant , usually the highest ranking nco in a line unit 1st cav 1st cavalry division 40 mm 40 millimeter grenades , fired from a grenade launcher 5 ton unarmored cargo truck 9 line request for medvac acu army combat uniform , the grey camouflage fielded by the army in 2005 afn armed forces network ( military television & radio ) ait advanced individual training , where you learn your job skill after basic training allah akbar ( sp ) `` god is great '' , shouted by the enemy as they attacked americans ao area of operations apache / ah-64 helicopter gunship arcom army commendation medal bah basic allowance for housing ( non taxable money soldiers get for living off base ) bc usually battalion commander , a lieutenant colonel bct basic combat training blackhawk / uh-60 transport helicopter bronze star medal cas close air support chinook / ch-47 transport helicopter chu containerized housing unit , basically a 10 x 20 trailer that housed up to 8 soldiers at a time .