RE: Goldberg Ultimate 10-300 ARF .60
Try this with your Ult. Go into a verticle line and climb to about 150'. Then do a stall turn/hammerhead. When the plane falls over instead of putting the rudder to neutral throw your flat spin inputs into it. After two spins let everything go and pull out like normal.
This is easy to do and looks cool. Mine is a slow flat spinner like yours.
David