"free" turbines and the freewheeling unit
is this a mistake:
the N2 stage of a "free" turbine engine acts as the freewheeling unit in the event of autorotation....
reason I ask is because I read somewhere - probably here - that certain types of turbine helicopters when in practice autos have slightly improved performance because the engine, while reduced to idle, is still supplying a small amount of power to the N2 stage (making for a slightly unrealistic practice performance). I don't know why I'm now just asking, but, any help?