▁Base , ▁in ▁Mar iet ta , ▁Georgia . ▁The ▁crash ▁was ▁attributed ▁to ▁dis eng agement ▁of ▁the ▁rud der ▁fly - by - wire ▁flight ▁control ▁system , ▁resulting ▁in ▁a ▁total ▁loss ▁of ▁rud der ▁control ▁cap ability ▁while ▁conduct ing ▁ground ▁minimum ▁control ▁speed ▁tests ▁( V mc g ). ▁The ▁dis eng agement ▁was ▁a ▁result ▁of ▁the ▁in ade qu ate ▁design ▁of ▁the ▁rud der ' s ▁integrated ▁actu ator ▁package ▁by ▁its ▁manufact urer ; ▁the ▁operator ' s ▁ins u fficient ▁system ▁safety ▁review ▁failed ▁to ▁consider ▁the ▁consequences ▁of ▁the ▁in ade qu ate ▁design ▁to ▁all ▁operating ▁reg imes . ▁A ▁factor ▁which ▁contributed ▁to ▁the ▁accident ▁was ▁the ▁flight ▁crew ' s ▁lack ▁of ▁engineering ▁flight ▁test ▁training . ▁ ▁In ▁the ▁ 1 9 9 0 s , ▁the ▁improved ▁C - 1 3 0 J ▁Super ▁Her cules ▁was ▁developed ▁by ▁Lock he ed ▁( l ater ▁Lock he ed ▁Martin ). ▁This ▁model ▁is ▁the ▁new est ▁version ▁and ▁the ▁only ▁model ▁in ▁production . ▁Extern ally ▁similar ▁to ▁the ▁classic ▁Her cules ▁in ▁general ▁appearance , ▁the ▁J ▁model ▁has ▁new ▁tur b op rop ▁engines , ▁six - bl aded ▁prop ellers , ▁digital ▁av ion ics , ▁and ▁other ▁new ▁systems . ▁ ▁Up gr ades ▁and ▁changes ▁In ▁ 2 0 0 0 , ▁Bo eing ▁was ▁awarded ▁a ▁ ▁contract ▁to ▁develop ▁an ▁Av ion ics ▁Modern ization ▁Program ▁k it ▁for ▁the