# Where is the lateral position of the aerodynamic center?

There is plenty of literature that describes how to find the aerodynamic centers (AC) longitudinal position.

But where would it be lateral?

My guess is somewhere near 1/3 out the wing from the fuselage, but I do not know..or would it maybe be close to the mean aerodynamic chord line?

• This is not an answer, but usually as we have two symmetrical wings, the center in on the symmetry axis. If the wings are loaded differently, then the problem is more complex. – mins Apr 9 '17 at 13:09
• Yes, and that probably why people are more concerned about the longitudinal position. But if an aircraft had only left wing, question is, where would it be.. – Invariant Apr 9 '17 at 13:17
• That question is more relevant than the comments make it: It needs to be answered when the wing spar is sized. The sad truth is: There is a multitude of lateral aerodynamic centers, depending on angle of attack, flap settings, aeroelastic deformation and control surface deflection. It is calculated separately for each of dozens of load cases during design. – Peter Kämpf Apr 9 '17 at 19:15

For a simple tapered half wing the aerodynamic centre spanwise location is at: $$y_{ac} = {{b}\over{6}} \cdot {c_r + 2c_t\over c_r+c_t}$$

where $b$ is the span, $c_r$ is the root chord and $c_t$ is the tip chord.

For a symmetric aircraft it should be at the centreline, since it's the combination of the two identical (but opposite sign) locations.

Source is a aicraft sizing code I wrote some years ago, I remember solving the integral for a simple tapered wing. Looking quickly at design books I can find the following image in Raymer, hope this helps: • Do you have any sources? – Gianni Alessandro Apr 10 '17 at 15:31
• what do the various terms mean? – Federico Apr 10 '17 at 19:02