Hi all,
I found this article on Ailes,about twin-rotor helicopter Project,and they mentioned that
the designer was from Netherland and his name is Mr. Volpert,I can't recognize if he
was the same Germany design; Ludger Volpert or not,can anyone help ?.
https://gallica.bnf.fr/ark:/12148/bpt6k9795858h/f5.item