Does anyone know where it was filmed ?

ASK-21, LN-GCJ, Drammen Flyklubb (http://www.dfk.no/) 59°45'36.83"N
9°55'3.78"E

Right over their airfield, just put the coordinates into Google Earth,
you'll recognize the place from what you see in the clip during the
first looping and during the low pass and approach/final.

Markus