threats posed by an unmanned aircraft, an unmanned aircraft system, or unauthorized unmanned aircraft system operations. (d) Airport improvement program eligibility Notwithstanding section 47102 of title 49, United States Code, the definition of the term airport development under that section shall include the purchase of equipment necessary to carry out Counter-UAS activities at commercial service airports. (e) Best practices (1) In general Not later than 1 year after the date of enactment of this Act, the Administrator of the Federal Aviation Administration and the Administrator of the Transportation Security Administration acting jointly and in collaboration with airport directors of commercial service airports, shall— (A) publish guidance regarding best practices for use of Counter-UAS Activities at commercial service airports