Yep. Totally reasonable to be dodgy about a link on a crank site. Engineering looks legit to me though (I have zero experience in the field). That said it's gone from the site, although the author has posted a bunch of articles.
I put Paul Lipps in the original submission title since he was the original author. His web page is not up anymore, so it's on some less than reliable site. The moderators' change lost that info.
Sadly not realized after Lipps died. However, with Lipps describing his thought process here, it seems likely that it would be possible to repeat it / learn from it.
I guess optional comment fields for links have been considered and decided against.
Mechanisms on this scale would seem relatively easy to test and compare. He's trying so hard to sell all the positive qualities of his propellors..... if they are so awesome, wouldn't they be easy to sell?
Fortunately, he'll sell it to you for only $15 a gram.