The 6A-series of cambered airfoils were described and reported in
NACA Rep. 903.
They use a special form of the 6-series camber line.
This special form is designated as the "A = 0.8 modified mean line."
The modification consists of holding the slope of the mean line constant from
the 80-percent chord station to the trailing edge.
This mean line is always used with 6A-series airfoils.
The equation for the 6A-series camber line is rather complicated and
there is little value in displaying it here.
It may be found