Excellent stuff David - thanks. I'll be using that spreadsheet soon. A Matlab program of it would be even cooler. One could make it an executable which then could run in the absence of Matlab on the local machine. It's been at least 10 years since Itouched the stuff though.
It seems to me that every time an engine is tested with various props, the APC's always deliver. They must be seriously efficient despite their weight.
More importantly though, at almost 7 lbs of static thrust in a 5 lb plane, the rocket could practically take off right out of my hand pointed straight up. Ever try that with a pattern design? I haven't... yet.
David.