▁ 1 9 0 1 ▁the ▁giant ▁bal lo on ▁Pre us en ▁( Pr uss ia ) ▁of ▁ ▁rose ▁to ▁a ▁height ▁of ▁. ▁Early ▁air ships ▁were ▁little ▁more ▁than ▁el ong ated ▁bal lo ons ▁with ▁an ▁engine ▁sl ung ▁under ne ath . ▁These ▁craft ▁were ▁limited ▁in ▁size ▁because ▁their ▁bodies ▁were ▁non - rig id ▁and ▁could ▁not ▁be ▁made ▁too ▁long . ▁The ▁German ▁Count ▁Ferdinand ▁von ▁Ze ppel in ▁real ised ▁that ▁a ▁rig id ▁frame ▁could ▁support ▁a ▁much ▁larger ▁volume , ▁and ▁in ▁ 1 9 0 0 ▁the ▁Luft sch iff ▁Ze ppel in ▁ 1 ▁of ▁ ▁volume ▁and ▁ ▁length ▁took ▁briefly ▁to ▁the ▁air . ▁ ▁Early ▁fixed - wing ▁aer op lan es ▁were ▁mostly ▁single - eng ined . ▁When ▁the ▁Russian ▁Ig or ▁S ikor sky ▁designed ▁and ▁fle w ▁his ▁I ly a ▁Mur om ets ▁in ▁ 1 9 1 3 ▁it ▁became ▁not ▁only ▁the ▁first ▁four - eng ined ▁aircraft ▁but , ▁with ▁a ▁wing ▁span ▁of ▁ ▁and ▁l aden ▁weight ▁of ▁, ▁by ▁far ▁the ▁largest ▁and ▁heav iest ▁to ▁date . ▁By ▁comparison ▁the ▁L Z ▁ 1 8 ▁air ship , ▁which ▁fle w ▁the ▁same ▁year , ▁was ▁▁ ▁long ▁( the ▁en velope ▁had ▁a ▁capacity ▁of ▁) ▁and ▁a ▁empty ▁weight ▁of ▁ 2 0 ▁t onnes . ▁ ▁The ▁Be ard more ▁Inf lex ible ▁of ▁ 1 9 2 8 ▁had ▁a