Kunstflugfiguren during AB pilot training?
 

Perhaps one of the German speakers might be able to help me?

In a post war interview a LW pilot (Fw. Erich Brunotte) mentions several aerobatic maneuvers that pilots were required to master to get their wings: HSK 1, HSK 2 usw. up to HSK 5 which he describes as a type of "Hammerhead stall" that could only be done in a Buecker 133 Jungmeister (apparently other less robust training a/c invited disaster as the tail unit could snap off in the resulting whip stall).

Does anyone know what "HSK" means? Or even better, what each HSK figuren was called? I imagine some of these are likely aerobatic figures such as a loop, a split-S, an Immelmann and possibly a Cuban eight - but I am guessing.
Thank you!

Link to the interview where these are mentioned by Fw Brunotte: http://video.flyingheritage.com/v/11...h-brunotte.htm