counter-UAS system means a system or device capable of lawfully and safely disabling, disrupting, or seizing control of an unmanned aircraft or unmanned aircraft system. (49) public unmanned aircraft system means an unmanned aircraft system that meets the qualifications and conditions required for operation of a public aircraft. (50) small unmanned aircraft means an unmanned aircraft weighing less than 55 pounds, including everything that is on board or otherwise attached to the aircraft. (51) unmanned aircraft means an aircraft that is operated without the possibility of direct human intervention from within or on the aircraft. (52) unmanned aircraft system means an unmanned aircraft and associated elements (including communication links and the components that control the unmanned aircraft) that are required for the pilot in command to operate safely and efficiently in the national airspace system. (53) UTM means an unmanned aircraft traffic management system or service. . 343. Special rules for model aircraft (a) In general Notwithstanding any other provision of law relating to the incorporation of unmanned aircraft systems into Federal Aviation Administration plans and policies, including this subtitle, the Administrator of the Federal Aviation Administration may not promulgate any rule or regulation regarding a model aircraft or an aircraft being developed as a model aircraft, except for— (1) rules regarding the registration of certain model aircraft pursuant to section 44103