Sweptwing

Sweptwing refers to an aircraft wing whose leading edge is angled backward from perpendicular to the fuselage. The sweep reduces wave drag at high subsonic and transonic speeds and raises the effective critical Mach number, enabling higher cruise and approach speeds. Swept wings may be fixed or part of a variable-geometry system and are standard on most modern jet aircraft.

From an aerodynamics standpoint, sweep shifts drag characteristics: it lowers wave drag but can increase induced drag at lower speeds. Sweep also affects stall behavior, often moving stall toward the wing root or tip depending on airfoil, twist, and aspect ratio. Structural implications include higher bending moments and the need for stronger spars, as well as control surface effectiveness along a swept planform.

The concept emerged in the early 20th century, with German researchers such as Adolf Busemann formulating the benefits of wing sweep for transonic flight. By the 1950s, swept wings were common on jet fighters and transport aircraft, and later designs introduced variable-geometry wings that sweep during flight to combine high-speed performance with low-speed handling.

Variants include fixed swept wings, cranked-arrow wings which blend straight and swept sections to improve stall margins, and variable-sweep (swing) wings used on aircraft such as the F-14 Tomcat and B-1 Lancer. Modern implementations often pair moderate sweep with advanced airfoils, wing-fuselage shaping, and optionally supercritical optimization to minimize drag across a broad speed range.