Tu-160 has a lift-generating airframe, which is mostly made of aluminum alloys. Titanium alloys make up to 20% of the airframe mass. The bombers airframe has a distinctive appearance, with the wing and fuselage gradually integrated into a single-piece configuration. The variable geometry wings (the sweep angle can be varied from 20 to 65) allow the aircraft to use complex flight profiles from low subsonic speeds to mach 2.