Bruce,

Not by any means am I trying to say that you are wrong - hell man I am just an ol' accountant.

The way that I got my setup to make sense was to picture the airflow as it came out from under the wingtip, and how the winglet was placed inside of that local flow. [sm=idea.gif]

The towout makes sense then.

Remember too that the Whitcombe is positioned from the wing TE, and has a fairly severe rake - the TE is 38* from vertical if I recollect and you have to figure that into the mix as well.

I can tell you that it makes a very good mentate for those long evenings around this time of year when there is nothing to watch on tv...