On Oct 5, 9:04*pm, brian whatcott wrote:

Here's a start: Willford's spreadsheet on light aircraft performance

*http://www.eaa.org/sportaviation/200...ceEstimate.xls

Thanks. That's the one I was thinking about first. The other one
(o612) is the one about hulls, which is what I was really after. I'm
looking for a hull design tool for an airboat idea I found on the
Internet a while back: some guy put a platform, two seats, an engine
and prop on a pair of airplane floats. I was wondering whether it was
as good an idea as it might be; I have no idea whether thing
was .built.