Hi Barcli - it's a generic thing that I picked up when in Ozark a few yrs ago. It's not official
AFAIK but makes enormous sense! I don't do them in the Pitts with the same eng prop combo but have done them in a wooden bladed S1 with a solid crank.
No idea how things work in Poland.
Good luck!
Your Yellow Husky vid on YouTube is awesome!!
Stik