▁time ▁ 4 5 ▁examples ▁had ▁been ▁built . ▁ ▁Vari ants ▁ ▁El ster ▁Pro totype ▁aircraft ▁fitted ▁with ▁a ▁ 5 2 ▁h p ▁Por sche ▁ 6 7 8 / 3 ▁engine , ▁first ▁flight ▁ 1 0 ▁January ▁ 1 9 5 9 . ▁ ▁El ster ▁B ▁ ▁Main ▁production ▁version ▁fitted ▁with ▁a ▁ 9 5 ▁h p ▁Cont inental ▁C - 9 0 ▁engine . ▁ 2 5 ▁aircraft ▁were ▁operated ▁by ▁the ▁Luft wa ffe ▁and ▁Marine fl ie ger ▁sport ▁flying ▁groups . ▁These ▁aircraft ▁were ▁initially ▁operated ▁with ▁civil ian ▁registr ations ▁but ▁were ▁allocated ▁military ▁serial s ▁in ▁ 1 9 7 1 . ▁In ▁ 1 9 7 8 ▁the ▁maintenance ▁contract ▁with ▁P üt zer ▁exp ired ▁and ▁the ▁aircraft ▁were ▁placed ▁on ▁the ▁civil ▁market . ▁ ▁El ster ▁C ▁The ▁El ster ▁C ▁was ▁fitted ▁with ▁the ▁more ▁powerful ▁ 1 5 0 ▁h p ▁Ly coming ▁O - 3 2 0 ▁engine ▁and ▁other ▁modifications ▁for ▁use ▁as ▁a ▁gl ider ▁t ug . ▁ ▁Oper ators ▁ ▁Military ▁operators ▁ ▁Luft wa ffe ▁Marine fl ie ger ▁ ▁Spec ifications ▁( P üt zer ▁El ster ▁B ) ▁ ▁See ▁also ▁ ▁References ▁ ▁Further ▁reading ▁ ▁External ▁links ▁ ▁Ph oto ▁of ▁El ster ▁B ▁in ▁Luft wa ffe ▁mark ings ▁ ▁El ster ▁Category : 1 9 5 0 s ▁German ▁civil ▁utility ▁aircraft ▁Category : 1 9 5 0 s ▁German ▁military ▁utility