Aerodynamic center

[1] The lift and drag forces can be applied at a single point, the center of pressure.

However, the location of the center of pressure moves significantly with a change in angle of attack and is thus impractical for aerodynamic analysis.

Instead the aerodynamic center is used and as a result the incremental lift and drag due to change in angle of attack acting at this point is sufficient to describe the aerodynamic forces acting on the given body.

But for cambered airfoils the aerodynamic center can be slightly less than 25% of the chord from the leading edge, which depends on the slope of the moment coefficient,

In precision experimentation with real airfoils and advanced analysis, the aerodynamic center is observed to change location slightly as angle of attack varies.

In most literature however the aerodynamic center is assumed to be fixed at the 25% chord position.

The distribution of forces on a wing in flight are both complex and varying. This image shows the forces for two typical airfoils, a symmetrical design on the left, and an asymmetrical design more typical of low-speed designs on the right. This diagram shows only the lift components; the similar drag considerations are not illustrated. The aerodynamic center is shown, labeled "c.a."