Konrad,
a very interesting contribution, the zero ground speed flying. I have observed often the dicussion of the 'ground turbulence", where there is in reality a stall.
I myself have already damaged some planes by this phenomenum, but by the time it became clear that it was'nt turbulence.
I was not active in this forum for some time, because I changed my eye lenses from bio to plastic, which took about half a year of adaptation (focus on the left eye 2m , on the right eye infinite, poor brains!)
Greetings from Rio
Kurt
www.kurt-rio.com