A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing configuration and is the simplest to build. However, during the early years of flight, these advantages were offset by its greater weight and lower manoeuvrability, making it relatively rare until the 1930s. Since then, the monoplane has been the most common form for a fixed-wing aircraft. Characteristics Support and weight The inherent efficiency of the monoplane is best achieved in the cantilever wing, which carries all structural forces internally. However, to fly at practical speeds the wing must be made thin, which requires a heavy structure to make it strong and stiff enough. External bracing can be used to improve structural efficiency, reducing weight and cost. For a wing of a given size, the weight reduction allows it to fly slower and with a lower-powered and more economical engine. For this reason, all monoplane wings in the pioneer era were braced and most were up until the early 1930s. However, the exposed struts or wires create additional drag, lowering aerodynamic efficiency and reducing the maximum speed. High-speed and long-range designs tend to be pure cantilevers, while low-speed short-range types are often given bracing. Besides the general variations in wing configuration such as tail position and use of bracing, the main distinction between types of monoplane is where the wing is mounted vertically on the fuselage. Low A low wing is one which is located on or near the bottom of the fuselage. Placing the wing low allows good visibility upwards and frees the central fuselage from the wing spar carry-through. By reducing pendulum stability, it makes the aircraft more manoeuvrable, as on the Spitfire; but aircraft that value stability over manoeuvrability may then need some dihedral. A feature of the low-wing position is its significant ground effect, giving the plane a tendency to float farther before landing. Conversely, this ground effect permits shorter takeoffs. Mid A mid wing is mounted midway up the fuselage. The carry-through spar structure can reduce the useful fuselage volume near its centre of gravity, where space is often in most demand. Shoulder A shoulder wing (a category between high-wing and mid-wing) is a configuration whereby the wing is mounted near the top of the fuselage but not