A turbine blade having a root and a tip and an airfoil with a core section made of composite material and a protective sheath or layer joined to the composite core at a location or locations exposed to erosion is described with the composite core of the airfoil being continuous from a location in vicinity of the root to a location in vicinity of the tip of the blade and including a section which widens with distance from the rotational axis along the length of the airfoil and which ends at the location in vicinity of the tip of the blade. The protective sheath or layer is secured by interference fit with widening section of the core.