Normal Mode and Idle Up Mode are the two flight modes most frequently used by collective pitch helicopter pilots.  Idle Up mode is what most RC helicopter collective pitch pilots fly.  In Idle Up mode, the rotor spins at a high speed regardless of the throttle stick position.  The most common Idle Up mode has a linear pitch curve (from minimum to maximum) and a flat throttle curve.  If a governor is in use, the throttle curve is a constant value, or a V curve may be used to provide more power at the extremes where the blade resistance is the greatest.