▁AG M - 8 6 C ▁C AL CM . ▁This ▁modification ▁also ▁replaced ▁the ▁B ▁model ' s ▁terrain ▁cont our - match ing ▁guidance ▁system ▁( TER COM ) ▁and ▁integrated ▁a ▁G PS ▁cap ability ▁with ▁the ▁existing ▁in ert ial ▁navigation ▁system ▁computer ▁. ▁ ▁AG M - 8 6 C / D ▁The ▁AG M - 8 6 C ▁is ▁a ▁Con vent ional ▁Air - Launch ed ▁Cru ise ▁Miss ile ▁( C AL CM ) ▁and ▁is ▁a ▁conventional ▁bl ast / fragment ation ▁derivative ▁of ▁the ▁nuclear ▁armed ▁AG M - 8 6 B . ▁The ▁AG M - 8 6 D ▁is ▁the ▁pen etr ator ▁version ▁of ▁the ▁C AL CM ▁which ▁is ▁designed ▁to ▁attack ▁deeply ▁buried ▁targets . ▁ ▁In ▁ 1 9 9 6 ▁and ▁ 1 9 9 7 , ▁ 2 0 0 ▁additional ▁C AL CM s ▁were ▁produced ▁from ▁excess ▁A LC M s . ▁These ▁miss iles , ▁designated ▁Block ▁I , ▁incorpor ate ▁improvements ▁such ▁as ▁a ▁larger ▁and ▁improved ▁conventional ▁payload ▁( 3 , 0 0 0   p ound ▁bl ast ▁class ), ▁a ▁multi - channel ▁G PS ▁receiver ▁and ▁integration ▁of ▁the ▁buffer ▁box ▁into ▁the ▁G PS ▁receiver . ▁The ▁upgrad ed ▁av ion ics ▁package ▁was ▁retro f itted ▁into ▁all ▁existing ▁C AL CM ▁( Block ▁ 0 ) ▁so ▁all ▁AG M - 8 6 C ▁miss iles ▁are ▁electron ically ▁identical . ▁ ▁Oper ations