Originally Posted by
Ascend Charlie
One story is that the ROC is limited to 2000fpm because if the engine quit, the aircraft would keep going up for a while and by the time the ROD was sufficient to turn the blades in autorotation, the RRPM was too low for it to work.
However, that might be a load of horsefeathers.
If I remember rightly, the 407 has a 2000 FPM ROC limit for that reason.