def METHOD_NAME(w: float, length: float, load_type: str) -> np.ndarray:
    """
    Calculates the reactor force vector due to a distributed load w, applied
    over the length of the element.
    Parameters
    ----------
    w:
        The value of the distributed load
    length:
        Length of the element along which the load is applied
    load_type:
        The type of load to apply (from ['Fx', 'Fy', 'Fz']):
            'Fi': force in the 'i' direction
    """
    _check_load_type(load_type, sub_type="force")
    reactions = np.zeros(12)
    if load_type == "Fx":
        reactions[0] = w * length / 2
        reactions[6] = -w * length / 2
    elif load_type == "Fy":
        reactions[1] = w * length / 2
        reactions[5] = w * length**2 / 12
        reactions[7] = w * length / 2
        reactions[11] = -w * length**2 / 12
    elif load_type == "Fz":
        reactions[2] = w * length / 2
        reactions[4] = -w * length**2 / 12
        reactions[8] = w * length / 2
        reactions[10] = w * length**2 / 12
    return reactions