▁US AF . ▁The ▁" 3 " ▁den oting ▁the ▁third ▁variation ▁in ▁design ▁for ▁the ▁H ▁series . ▁Im prov ements ▁included ▁ring ▁las er ▁gy ros ▁for ▁the ▁IN Us , ▁G PS ▁rece ivers , ▁a ▁partial ▁glass ▁co ck pit ▁( AD I ▁and ▁H SI ▁instruments ), ▁a ▁more ▁capable ▁AP N - 2 4 1 ▁color ▁rad ar , ▁night ▁vision ▁device ▁compatible ▁instrument ▁light ing , ▁and ▁an ▁integrated ▁rad ar ▁and ▁miss ile ▁warning ▁system . ▁The ▁elect rical ▁system ▁upgrade ▁included ▁Gener ator ▁Control ▁Units ▁( GC U ) ▁and ▁Bus ▁Switch ing ▁units ▁( BS U ) ▁to ▁provide ▁stable ▁power ▁to ▁the ▁more ▁sensitive ▁upgrad ed ▁components . ▁ ▁The ▁equivalent ▁model ▁for ▁export ▁to ▁the ▁UK ▁is ▁the ▁C - 1 3 0 K , ▁known ▁by ▁the ▁Royal ▁Air ▁Force ▁( RA F ) ▁as ▁the ▁Her cules ▁C . 1 . ▁The ▁C - 1 3 0 H - 3 0 ▁( Her cules ▁C . 3 ▁in ▁R AF ▁service ) ▁is ▁a ▁stretch ed ▁version ▁of ▁the ▁original ▁Her cules , ▁achieved ▁by ▁inserting ▁a ▁ 1 0 0   in ▁( 2 . 5 4   m ) ▁plug ▁a ft ▁of ▁the ▁co ck pit ▁and ▁an ▁ 8 0   in ▁( 2 . 0 3   m ) ▁plug ▁at ▁the ▁rear ▁of ▁the ▁fus el age . ▁A ▁single ▁C - 1 3 0 K ▁was ▁purchased ▁by ▁the ▁Met ▁Office ▁for