My name is Malcolm Whapshott, I am 49 50 years old ancient and I live with my wife and cat 2 cats in a small Hampshire town in England. My hobbies include my interest in human powered flight, photography  and my computer (which I could not live without) used for programming, designing web sites as well as keeping in touch with the rest of the world.

Propeller design

Many years ago I was interested in the problems of human powered flight. While designing a HPA I came across the specific problem of propeller design. Initially I used very simple aerofoil theory to generate a design, then I came across the more complex blade element theory. This required a programable calculator for some basic calculations. The program ran for a number of hours and returned a figure for efficiency.

This program was then rewritten and expanded for an Apple 2 computer which produced some visual output of propeller angles.

Other things came up and the problem was forgotten until a couple of years ago when I was wondering what to do with my computer and realised that a combination of vastly increased computing power and the internet would allow me to write a considerably better version of my propeller design program to allow for the variation in Reynolds number along the blade and allow me to distribute it.

Kremer endurance prize

I had resisted the temptation to write about general Human powered aircraft design and construction and concentrate on the propeller design, resisting the temptation to write about more than the propeller and the transmission associated with the propeller but the announcement of the new prize made me expand the site to it’s present size. The information is generally simplified and the amount of previous knowledge is assumed to be minimal.

More information is being added when I find time.


I still have my original programmable calculator although I don’t bother programming it now. It was used to check the calculations in Prop Designer however.

The author flying about 90 metres off the ground in a tethered balloon. Photo by Dawn Whapshott.

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