The point is that the translational velocity is added to the circumferential velocity. In addition, the velocity of local currents due to the streamline of the profile is always greater. Local compaction jumps appear, noise and power losses increase sharply. Therefore, the circumferential speed is usually limited to 220 m/s, 240 in extreme case. Of course, the saber-shaped blade shape partially mitigates the negative effects of the sweep.