Helicopter blades can "spin" as fast as 500 rpm and as low as 179 rpm (RPM = revolutions per minute).
How Fast Do The Rotor Blades On A Helicopter Spin Per Minute (i'm Doing A Project At School I Gotta Know Soon) Please Don't Make Jokes I Need To Know! :)?
The usual range is 300 to 500 rpm. Note that the rotation rate for any given helo is normally quite steady, it's the blade pitch that is varied to rise, fall and travel.