What is Variable Sweep?
Variable sweep is a term used to describe an airplane that has the ability to change the sweep of its wings. It allows the aircraft wing to change shape to fit a specific need. A straight wing is the most efficient design for low speed flight, but for aircraft designed to fly at high speeds the most efficient design is for the wing to be swept back. An aircraft with the ability to change its wing sweep would allow the pilot to use the most efficient wing sweep for the aircraft’s current speed, slow or fast. The greater efficiency to fit the speed the plane is flying at offsets the weight and volume of the Swing mechanism. However due to the higher complexity and cost this design is better suited toward military aircraft. This design was introduced in the 1940s and saw many different designs using this technology. However new designs stopped using this technology in the 1980s due to new advances in wing designs and aeronautical technologies.
How Does It Work?
The mechanics of the design are rather simple. All the mechanism is is a big hinge connecting the wing spar at the root and a big hydraulic cylinder or spindle drive for adjusting the sweep angle. Each design that uses variable sweep will have some variation of the above descriptions.
Exceptions
There are some other variations on a variable geometry aircraft, one being the NASA test aircraft AD-1 with an Oblique wing design in which the whole wing pivots on a single point. But for the sake of simplicity, this site will only go into the variable sweep aircraft that have symmetrical wings that both sweep back or forward at the same time.
