BRL-CAD's translation of the calculation of coordinates for NACA airfoils is
based on the public domain program naca456 written by Ralph Carmichael of
Public Domain Aeronautical Software (PDAS):

http://www.pdas.com/naca456.html

naca456 is in turn based off of earlier work by several authors at NASA,
documented in reports NASA TM X-3284, NASA TM X-3069 and NASA TM 4741. The
program naca456 is documented in the paper:

Carmichael, Ralph L.: Algorithm for Calculating Coordinates of Cambered NACA
Airfoils At Specified Chord Locations. AIAA Paper 2001-5235, November 2001.

Disclaimer, per the PDAS distribution:

Although many of the works contained herein were developed by national
laboratories or their contractors, neither the U.S. Government nor Public
Domain Aeronautical Software make any warranty as to the accuracy or
appropriateness of the procedure to any particular application.

The programs and descriptions have been collected and reproduced with great
care and attention to accuracy, but no guarantee or warranty is implied. All
programs are offered AS IS and Public Domain Aeronautical Software does not
give any express or implied warranty of any kind and any implied warranties are
disclaimed. Public Domain Aeronautical Software will not be liable for any
direct, indirect, special, incidental, or consequential damages arising out of
any use of this software. In no case should the results of any computational
scheme be used as a substitute for sound engineering practice and judgment.

file:/src/proc-db/naca/epspsi.c
file:/src/proc-db/naca/naca456.c
file:/src/proc-db/naca/naca.h
file:/src/proc-db/naca/nacax.c
file:/src/proc-db/naca/splprocs.c

