def send_extpos(self, pos):
        """
        Send the current Crazyflie X, Y, Z position. This is going to be
        forwarded to the Crazyflie's position estimator.
        """

        pk = CRTPPacket()
        pk.port = CRTPPort.LOCALIZATION
        pk.channel = self.POSITION_CH
        pk.data = struct.pack('<fff', pos[0], pos[1], pos[2])
        self._cf.send_packet(pk)