All aircraft developers struggle to make airfoil for wings, tails or propellers. A manually created spline will not guarantee precision of shape. Airfoils are represented as a set of X and Y coordinates in the DAT files. These coordinates should be multiplied on wing chord to get real X and Y coordinates of all points.
This script automates the creation of spline on XY origin from any DAT file with defined chord length.
DAT files could be found from following sites: