russian nato reporting feather designation type generation soviet fighter developed design bureau immediately world war reverse engineered german engine swedish jets successfully converted powered aircraft enter production aircraft built nominally fighter mainly qualify engine experienced pilots fly jets design development description april ordered develop single seat jet fighter equipped single german engine save time based new design known latest version successful engined fighter engine removed jet engine mounted underneath forward fuselage exhaust exited underneath middle fuselage protect fuselage steel added deeper forward fuselage gave aircraft pod boom configuration changes metal fuselage aircraft nose accommodate armament millimeter additional fuel tank engine engine changes wings elimination air oil cooler bending wing inverted shape clear engine vertical slightly enlarged tail plane conventional landing gear tail wheel steel leaf springs shock carried total kilograms fuel taxi tests began october proved short heat engine exhaust melted skin rear fuselage rubber tire modifications problems took late december time second prototype completed solid steel enlarged tests transferred scale testing lasted february 26th month issued requirements aircraft maximum speed mph sea level speed mph altitude meters able climb altitude half minutes range kilometers maximum speed prototypes ready flight testing september according aviation historians representatives tossed coin april determine aircraft soviet jet fly lost circuit airfield landing manufacturer flight testing aircraft completed june early success caused issue new requirement april aircraft powered soviet built engine known aside new engine requirement differed previous range kilometers cruise speed reduction maximum ceiling meters prototypes ordered available flight testing september able adapt existing prototypes little trouble aircraft participated august day aerial display summoned office ordered build aircraft participate november parade red square commemorating anniversary october revolution factory chosen build new aircraft building conventional easily switch jet fighter aircraft built deadline lacked armor provided enlarged fuel tank lieu armament incomplete outfit parade canceled aircraft modified single cannon began state acceptance trials lasted april tests revealed number problems thick wing inherited limited speed aircraft engine exhaust damaged surface airfield cockpit filled smoke oil engine aircraft short ranged despite problems proved easy fly pilots accustomed engined fighters caused accept fighter conversion trainer state acceptance trials completed ordered aircraft production december aircraft built january april equally split single seat aircraft seat trainers armed single cannon trainer ran development difficulties aircraft batch single participated day moscow total produced end year exclusive prototypes aircraft distributed small numbers fighter aviation regiments based ussr poland romania hungary use conversion trainers aircraft led number informal display teams late 1940s single prototype seat trainer aircraft production batch built factory fall prototype begin manufacturer flight testing april primary differences single seat version limited redesigned forward fuselage accommodated additional cockpit armament common sideways opening canopy trainer initially designated eventually designated documents refer work trainer cancelled success trainer version test prototype aerial system installation fighter bomber tanker test procedures fit april days flights ordered begin design new aircraft similar engine improved generally resembled original aircraft wings entirely redesigned flow tail structure enlarged seat fitted seat armoured pilot protected bullet proof entire canopy redesigned accommodate new landing gear housed thin wings redesigned fuselage low high wing loading wing versions considered low wing loading square meter wings chosen prototype altitude meters new fighter designated expected speed mph significant improvement production aircraft completed september ground tests lasted september flew ordered production conventional landing gear deemed obsolete survivors known surviving aircraft yellow outside moscow variants data family prototypes series powered captured engines referred initial designation prototypes early production aircraft powered soviet built engines copies reduced armament production aircraft armament seat training version built proceeded success trainer version trainer alternative designation alternative designation family improved improved drop tanks prototype proper relation earlier seat trainer version long greenhouse canopy tandem fighter trainer production seat trainers production fighters alternative designation relation earlier similar unrelated aircraft experimental aircraft similar appearance aircraft actually largely new incorporating improved seat protection pilot sole prototype remained development cancelled september taxi tests carried users soviet_union specifications data history aircraft general characteristics crew length wingspan wing area weight gross weight fuel capacity powerplant lbf thrust performance maximum speed mph combat range nmi service ceiling rate climb min wing loading armament guns cannon rounds
Yakovlev Yak-15