▁a ▁narrow body ▁design ▁with ▁a ▁ ▁payload . ▁When ▁the ▁AF RL ▁increased ▁the ▁payload ▁requirement ▁to ▁, ▁they ▁tested ▁a ▁ 5 ▁percent - scale ▁model ▁of ▁a ▁wide body ▁design ▁with ▁a ▁ ▁take - off ▁gross ▁weight ▁and ▁an ▁" A 4 0 0 M - size " ▁ ▁wide ▁cargo ▁box . ▁It ▁would ▁be ▁power ed ▁by ▁four ▁I AE ▁V 2 5 3 3 ▁tur bo f ans . ▁In ▁August ▁ 2 0 1 1 , ▁the ▁AF RL ▁released ▁pictures ▁of ▁the ▁Lock he ed ▁Speed ▁Ag ile ▁concept ▁demonstr ator . ▁A ▁ 2 3 % ▁scale ▁model ▁went ▁through ▁wind ▁tunnel ▁tests ▁to ▁demonstrate ▁its ▁hy brid ▁power ed ▁lift , ▁which ▁comb ines ▁a ▁low ▁drag ▁air frame ▁with ▁simple ▁mechanical ▁assembly ▁to ▁reduce ▁weight ▁and ▁better ▁aer od ynam ics . ▁The ▁model ▁had ▁four ▁engines , ▁including ▁two ▁Williams ▁F J 4 4 ▁tur bo f ans . Lock he ed ' s ▁New ▁S TO L ▁Airl if ter ▁Design ▁ ▁- ▁Def ens ete ch . org , ▁ 1 5 ▁September ▁ 2 0 1 1 ▁On ▁ 2 6 ▁March ▁ 2 0 1 3 , ▁Bo eing ▁was ▁granted ▁a ▁pat ent ▁for ▁its ▁swe pt - wing ▁power ed ▁lift ▁aircraft . ▁ ▁As ▁of ▁January ▁ 2 0 1 4 , ▁Air ▁M ob ility ▁Command , ▁Air ▁Force ▁M ater iel ▁Command ▁and ▁the ▁Air ▁Force ▁Research ▁Lab ▁are ▁in ▁the