Rotor assembly having collective pitch control

A rotor assembly for an aircraft operable to generate a variable thrust output at a constant rotational speed. The rotor assembly includes a mast rotatable at the constant speed about a mast axis. A rotor hub is coupled to and rotatable with the mast. The rotor hub includes a plurality of spindle grips extending generally radially outwardly. Each of the spindle grips is coupled to one of a plurality of rotor blades and is operable to rotate therewith about a pitch change axis. A collective pitch control mechanism is coupled to and rotatable with the rotor hub. The collective pitch control mechanism is operably associated with each spindle grip such that actuation of the collective pitch control mechanism rotates each spindle grip about the respective pitch change axis to collectively control the pitch of the rotor blades, thereby generating the variable thrust output.