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zero, improving aerodynamic efficiency. This wing design is difficult and costly to manufacture because of the compound curves in its design. The elliptical wing is more efficient in terms of L$_{D}$, but the wing’s uniform lift distribution causes the entire span of the wing to stall simultaneously, potentially causing loss of control with little warning. 

## Rectangular Wing 

The rectangular wing is similar in efficiency to the elliptical wing, but is much easier to build. Rectangular wings have very gentle stall characteristics with a warning buffet prior to stall, and are easier to manufacture than elliptical wings. One drawback to this wing design is that rectangular wings create more induced drag than an elliptical wing of comparable size. 

## Tapered Wing 

The tapered wing is the planform found most frequently on gliders. Assuming equal wing area, the tapered wing produces less drag than the rectangular wing, because there is less area at the tip of the tapered wing. If speed is the primary consideration, a tapered wing is more desirable than a rectangular wing, but a tapered wing with no twist (also called washout) has undesirable stall characteristics. 

## Swept-Forward Wing 

A swept-forward planform is a wing configuration in which the quarter-chord line of the wing has a forward sweep. Swept-forward wings are used to allow the lifting area of the wing to move forward, while keeping the mounting point aft of the cockpit. This wing configuration is used on some tandem two-seat gliders to allow for a small change in center of gravity (CG) with the rear seat occupied, or while flying solo. This type of planform design gives the glider increased maneuverability due to airflow from wing tip to wing root, preventing a stall of the wing tips and ailerons at high angles of attack. Instead, the stall occurs in the region of the wing root. 

## Washout 

Washout is built into wings by putting a slight twist between the wing root and wing tip. When washout is designed into the wing, the wing displays very good stall characteristics. Moving outward along the span of the wing, the trailing edge moves up in reference to the leading edge. This twist causes the wing root to have a greater AOA than the tip, and as a result, stall first. This provides ample warning of the impending stall and, at the same time, allows continued aileron control. 

