A US appeals court struck down a ruling Friday aimed at forcing recreational drone owners to register their tiny aircraft with the Federal Aviation Administration.
The FAA had ordered owners of small drones characterized as "model aircraft" to register them, with the aim of curbing illegal flights near airports or interfering with civil aviation, but critics said the move went too far.
The decision by the federal appeals court in Washington was a snub for the FAA, which drew up the rule in 2015 after consulting with aviation experts on ways to tackle the growing number of drones taking to the air, and which were seen as a potential threat to flight safety and personal privacy.
The new rule stipulated that anyone owning a drone weighing more than half a pound (227 grams) would have to register their name and address with the FAA, as well as place an identification number on the vehicle's motor.
But drone owner John Taylor launched a legal challenge, arguing that the new demands infringed on his right to fly his drone at his home in the US capital.
He argued that the FAA did not have jurisdiction over the flights of model aircraft -- a line the three judges of appeals court accepted, ordering the rule to be overturned.
Small remote-controlled drones can be as much a child's toy as a sophisticated machine capable of performing acrobatic flights or shooting aerial footage in the hands of enthusiasts.
US law in theory prohibits drones from flying at more than 400 feet (120 meters) in the vicinity of airports or within restricted areas like the center of the capital city.
But authorities find it difficult to enforce those rules in practice, and drone users frequently ignore them.
In a statement the FAA said the registration rule had aimed "to ensure that drones are operated in a way that is safe and does not pose security and privacy threats."
"We are in the process of considering our options and response to the decision," it said.