O ' s ▁Central ▁Army ▁Group . ▁▁ 1 st ▁Battalion , ▁ 5 1 st ▁Infantry ▁( M ech ), ▁at ▁C rails heim , ▁part ▁of ▁the ▁ 1 st ▁Brigade , ▁was ▁de activ ated ▁on ▁ 1 6 ▁June ▁ 1 9 8 4 ▁as ▁a ▁result ▁of ▁the ▁division ' s ▁conversion ▁to ▁the ▁Division ▁ 8 6 ▁force ▁structure . ▁Under ▁the ▁Division ▁ 8 6 ▁structure , ▁each ▁heavy ▁division ▁decre ased ▁by ▁one ▁inf antry ▁batt alion , ▁while ▁remaining ▁inf antry ▁batt al ions ▁gained ▁one ▁additional ▁rif le ▁company . ▁ ▁On ▁ 1 6 ▁April ▁ 1 9 8 6 , ▁the ▁A viation ▁Brigade , ▁ 1 st ▁Arm ored ▁Division , ▁was ▁activ ated ▁in ▁Germany . ▁ ▁In ▁April ▁ 1 9 8 7 , ▁ 6 th ▁Battalion , ▁ 4 3 rd ▁Air ▁Def ense ▁Art illery ▁( Pat ri ot ) ▁moved ▁to ▁a ▁newly - built ▁U rl as ▁Kas erne ▁( located ▁near ▁B ism ar ck ▁& ▁K atter bach ▁Kas erne ) ▁assigned ▁to ▁the ▁ 1 st ▁Arm ored ▁Division . ▁ ▁On ▁ 1 6 ▁November ▁ 1 9 8 7 , ▁the ▁ 5 0 1 st ▁Com bat ▁A viation ▁Battalion ▁was ▁de activ ated ▁and ▁re - flag ged ▁as ▁ 2 nd ▁Battalion , ▁ 1 st ▁A viation ▁Regiment ▁at ▁K atter bach ▁Kas erne , ▁Federal ▁Republic ▁of ▁Germany , ▁under ▁the ▁ 1