Builder Resources

NACA Duct Templates

The following is a set of printable templates for NACA ducts.  The templates were created according to the dimensions given in Tony Bingelis' Aircraft Construction Methods book from The Sportplane Builder series, page 187.  The templates were drawn with an aspect ratio (width/height) of 4, where the prefered number is between 3 and 5, therefore going "middle of the road".  The NACA ducts below are referenced by their Width.  The length of the duct is a function of the width and aspect ratio while the side walls are a function of the ducts width and length.  These templates can be used for cutting out the NACA duct openings (Verify it will work with your NACA duct if you've purchase pre-formed ducts) or to create your own NACA ducts from scratch.  Verify that the width of the duct when printed is equal to the stated size of the printout to ensure the printer has reproduced the drawings accurately.  If you should need a NACA duct template of a different aspect ratio or of a different width that is not listed, please feel free to contact me with the information you need and I'll generate a template for your requested size.  The templates listed below will print on standard 8.5x11 paper in landscape format.


Better Half VW Build

The following PDF is a writeup pertaining to the 1/2 VW engine build for my Legal Eagle ultralight.  I chose to go with a stroker crank and larger bore cylinders for some extra power and the article details the trials and tribulations of the build from going that route.