Swept Wing

A swept-wing is a wing planform common on high-speed aircraft. A swept-wing is typically swept back, instead of being set at right angles to the fuselage. Forward sweep is also used on some aircraft. They were initially used only on fighter aircraft, but have since become almost universal on jets, including airliners and business jets.

This applies to the wing as well, which suggests that wings should have very low aspect ratios, long chord, and be very thin. Examples of this sort of wing can be found on the F-104 Starfighter for instance, which is highly optimized for high-speed performance. However, these same characteristics make a wing have much higher drag at low speeds, and generally have poor performance. The Starfighter is somewhat infamous as a "widowmaker" due to the large number of landing accidents caused by its very fast landing speeds.

Swept wings essentially "fool" the airflow at high speeds into thinking the wing has a longer and flatter profile than it has as measured "head on" to the wing. At high speeds, airflow over the wing travels almost directly front to back, so a wing swept at 45 degrees would see an effective chord 1.4 times the actual chord. This reduces the effects of wave drag, making transonic flight much more economical.