Mark Steitle,

In Martin Hollmann's book "Modern Aircraft Design, Volume 1" he reports that
the IV wing root was designed by Rick McWilliams and is designated as a
RXM5-217. He notes that this has a favorable pressure gradient in cruise and
a larger leading edge radius than typical laminar flow airfoils. The
Jones-Joukowski parameters are:
Xc=-0.086, Yc=0.030, Xt=1.051, Yt=0.004 and D=0.100.

The tip is a NACA 64212 and they performed a linear interpolation between
the to airfoil sections from tip to root. Also note that they included 2
degrees of washout at the tip.

The Horizontal and Vertical tails are NACA 63015.

Unless Lance changde these from when Martin was involved, this data should
still be correct.

Regards,
Mike Hutchins