Playing around with Vmca is bound to lead to trouble eventually. An RAAF Hercules in 1960 did a three turn spin before recovery following a Vmca situation during dual conversion. The aircraft was badly damgaged and almost a write-off and in fact Lockheed were interested in exactly what spin recovery action the pilot took as there has been previous spin accidents in Hercs and the aircraft failed to recover. There have been numerous cases of light twins going into a spin during Vmca "demonstrations" - or should we say cock-ups.