A plane no longer made by Balsa USA was the Super Stick for a 60. This had a swept back rudder and fin. It was east to get into a spin and recover but a flat spin was a true adventure. Once in you couldnt recover, we tried 6 different models and the results were the same.
If into the spin we increased power and the rotation increased and suprisingly we would land about 40% of the time with the motor running and take off. Other times it was straighten out the gear and go fly again.
This was again demonstrated when the first hershey bar funfly models appeared and full power flat spins were accomplished.

Dennis