I have been messing around with designing my own plane. I am just doing a one-off design so I am just using paper, pencil and calculator. I thought I'd toss this out for folks to chew on, spit out or enjoy. Below is an equation that describes a turtle deck former (90 deg to datum). It's basicly an upside down parabola. I graphed the equation and it looks OK. Think it will work?

f(x) = h - [4h(x-w/2)^2]/w^2

h = max height
w = max width
x = ranges from 0 to w

I have not tried the first turtle deck former that is usually angled back, but one needs to modify h to:

h = (a^2 + b^2)^0.5 a=distance back horizontally, b=max height vertically (see picture below)

I attached a Maple 8 plot of the first equation (h = 7 cm, w = 8 cm). Looks like a turtle deck. Now I need to cut it out. I suppose basic math does have purpose????