Drag

An aerodynamic force acting in the same plane as the relative wind striking an airfoil. Two basic types of drag act on an aircraft in flight: induced drag and parasite drag. Induced drag is caused by the same factors that produce lift, and its amount varies inversely as the airspeed. As the airspeed decreases, the angle of attack must increase, and this increases the induced drag. Parasite drag is caused by the friction of air moving over the structure, and its amount varies directly as the airspeed. The higher the airspeed, the greater the parasite drag.