soviet prototype longer ranged version bomber built world war canceled favor program offered range sole prototype test programs ending days target development designed modernized enlarged greater range achieved use fuel efficient engines better adding fuel tanks intended range kilometres carry maximum bomb load kilograms speed kilometres hour mph work began design february confirmed order june required prototype ready state acceptance trials july forward portion fuselage redesigned style stepped fuselage lengthened allowed bomb bays doors lengthened radar operator moved forward compartment radar located chin position new streamlined wings enlarged total square metres rubber boots replaced efficient aerodynamic bleed air engine redesigned smaller cross sections drag originally engines considered engine ready fully propellers changes increased lift drag ratio construction began november components possible speed construction flight wasn december canceled program september favor expected better performance research aircraft testing pitch propellers structural heavy aircraft eventually target bombing gunnery range specifications data russian aircraft general characteristics length wingspan height wing area weight loaded weight max takeoff weight powerplant cylinder row radial engine performance maximum speed mph range nmi service ceiling wing loading power mass armament bombs bombs
Tupolev Tu-80