Yes, you can follow the instrunctions on this site
http://www.digital-eel.com/sirl/flyplane.htm
And build your very own FLY plane. But is it cruel? No! The site has inspirational words to cover that:
"It should fly like a charm, and, far from being cruel to the flies, you'll be teaching them a new and valuable thing, one that brings us to the virtue of this exercise. For we see that while flies think a lot alike, have a great deal in common, share many of the same hopes and dreams, they never act in concert, as a team, with regard for the worth of other, neighboring flies until forced to by grim circumstance - as, for example, when they are harnessed to fly and either first experience the exhilaration of high-altitude cooperation or die."
If only all such instructional sites contained this kind of high philosophy.