code: def cmd_changealt(self, args):
          '''change target altitude'''
          if len(args) < 1:
              print("usage: changealt <relaltitude>")
              return
          relalt = float(args[0])
          self.master.mav.mission_item_send(self.settings.target_system,
                                            self.settings.target_component,
                                            0,
                                            3,
                                            mavutil.mavlink.MAV_CMD_NAV_WAYPOINT,
                                            3, 1, 0, 0, 0, 0,
                                            0, 0, relalt)
          print("Sent change altitude command for %.1f meters" % relaltf cmd_changealt(self, args):
          '''change target altitude'''
          if len(args) < 1:
              print("usage: changealt <relaltitude>")
              return
          relalt = float(args[0])
          self.master.mav.mission_item_send(self.settings.target_system,
                                            self.settings.target_component,
                                            0,
                                            3,
                                            mavutil.mavlink.MAV_CMD_NAV_WAYPOINT,
                                            3, 1, 0, 0, 0, 0,
                                            0, 0, relalt)
          print("Sent change altitude command for %.1f meters" % relalt)
docs: change target altitude