Several Pilots of the German Army did those Acro-Displays for Air-Shows and Freestyle-World-Championships. One of the first was Cpt. Charly Zimmerman, who won the World-Championship the first Time in 1981, it was in Poland, as far as I remember.
I was attending the rehearsals in Ahlhorn,Germany one time, standing right beside a member of the American team (B 206 Pilot ), his words: Thats no helicopter, thats magic.
Severeal Western Teams met in Germany before the Championship and then cruised together to Poland a long way around Eastern Germany, the times had changed a lot since then.