A process for manufacturing a composite rotor blade includes manufacturing an oversized root region of a root region of a composite rotor blade; fixturing the CMC blade into a machining fixture at a primary Y and Z axis datum located at an attachment fillet radii of the root region; machining V-notches into the oversized root region to form a Y′ and Z′ axis datum of a sacrificial datum system in relation to the primary Y and Z axis datum; applying an oversized coating layer over the attachment fillet radii of the root region; fixturing the CMC blade into a machining fixture at the Y′ and Z′ axis datum of the sacrificial datum system; machining the oversized coating layer to a machined coating layer forming a Y″ and Z″ axis datum with respect to the Y′ and Z′ axis datum of the sacrificial datum system; fixturing the CMC blade into a machining fixture at the Y″ and Z″ axis datum; and machining off the sacrificial datum system removing the V-notches.