[aviatorsneah]

doesn't really have to do with throttling up slowly, but rather gaining speed at a lower throttle setting so as to give the rudder more effectiveness against torque and pfactor at higher power. torque and pfactor have more of an effect at slower speeds. this is why you bring the power in slowly on the takeoff roll.

i know a guy who owns and flys a P-51 at our airport and he says you can't even takeoff with full power in the thing....you'll run out of rudder.