, ▁which ▁in ▁turn , ▁was ▁first ▁designed ▁and ▁flow n ▁as ▁a ▁cargo ▁gl ider ▁in ▁ 1 9 4 7 . ▁The ▁Bo eing ▁C - 9 7 ▁Str at of re ighter ▁had ▁rear ▁ram ps , ▁which ▁made ▁it ▁possible ▁to ▁drive ▁vehicles ▁onto ▁the ▁air plane ▁( also ▁possible ▁with ▁forward ▁r amp ▁on ▁a ▁C - 1 2 4 ). ▁The ▁r amp ▁on ▁the ▁Her cules ▁was ▁also ▁used ▁to ▁a ird rop ▁cargo , ▁which ▁included ▁a ▁Low - alt itude ▁par ach ute - ext raction ▁system ▁for ▁Sher idan ▁t anks ▁and ▁even ▁dro pping ▁large ▁impro vised ▁" da isy ▁cut ter " ▁bomb s . ▁The ▁new ▁Lock he ed ▁cargo ▁plane ▁design ▁possessed ▁a ▁range ▁of ▁, ▁take off ▁cap ability ▁from ▁short ▁and ▁un prep ared ▁stri ps , ▁and ▁the ▁ability ▁to ▁fly ▁with ▁one ▁engine ▁shut ▁down . ▁ ▁Fair child , ▁North ▁American , ▁Martin , ▁and ▁North rop ▁decl ined ▁to ▁particip ate . ▁The ▁remaining ▁five ▁companies ▁tender ed ▁a ▁total ▁of ▁ten ▁designs : ▁Lock he ed ▁two , ▁Bo eing ▁one , ▁Ch ase ▁three , ▁Douglas ▁three , ▁and ▁Airl ifts ▁Inc . ▁one . ▁The ▁contest ▁was ▁a ▁close ▁affair ▁between ▁the ▁l ighter ▁of ▁the ▁two ▁Lock he ed ▁( pre lim inary ▁project ▁design ation ▁L - 2 0 6 ) ▁propos als ▁and ▁a ▁four - t urb op rop ▁Douglas ▁design . ▁ ▁The ▁Lock he