The Federal Aviation Administration announced new rules Dec. 14, requiring owners of remote-controlled recreational aircraft to register the machines in a national database. With radio-controlled drones predicted to be one of the most popular holiday gifts this year, and an increasing number of the aircraft interfering with the work of aviation, fire, and police officials, the registration process is meant for authorities to be able to track down owners of any flying machines that break the rules. Drone owners will have to fill out an online form with their names, home addresses, and email addresses to the F.A.A., and then affix a registration number to their drone. “Unmanned aircraft enthusiasts are aviators, and with that title comes a great deal of responsibility,” Anthony Foxx, the secretary of the Transportation Department, said in a conference call with reporters Dec. 14. “Registration gives us an opportunity to work with these users to operate their unmanned aircraft safely.” Only American citizens can register a drone at faa.gov/uas/registration/, beginning Dec. 21. Registration will be free for the first 30 days, then cost $5. The rules are for new drones, which must be registered before flight, and previously purchased aircraft, with registration required by Feb. 19, 2016.