An aviation industry task force is recommending that operators be required to register drones weighing as little as a half a pound, a threshold that could include some remote-controlled toys, industry officials said. Federal Aviation Administration officials who convened the 25-member task force on drone registration have said they want to avoid requiring the registration of toys. But the consensus of the task force is that the weight threshold that triggers registration should be set at 250 grams or above, which is about a half-pound, said people familiar with its deliberations. The threshold is based on the potential impact a drone that size would have if it fell from the sky and struck a person or if it collided with a helicopter or plane, they said. The recommendations were expected to be submitted to the FAA by Saturday. The FAA then can modify them, and hopes to issue the rules before Christmas to begin registering some of the thousands of drones expected to be purchased over the holidays. One industry official said the target date is December 21. Four people familiar with the advisory group's deliberations described the conclusions to The Associated Press, speaking on condition of anonymity because the FAA asked that the discussions be kept private. The registration requirement would apply to drone operators rather than individual drones to avoid requiring operators who own multiple drones to register more than once. The operator would receive a single registration number, which would then be affixed to the body of each drone. People who already own drones weighing more than a half-pound would have to register them. Registration could be done through an FAA website where an operator can provide name, address, phone number and other contact information and receive a registration number. The Consumer Technology Association estimates 700,000 drones will be sold in the U.S. this year, including 400,000 in the last quarter. FAA officials said when they announced the formation of the task force last month that they hoped registration will help create a "culture of accountability" among drone operators and allow owners to be tracked down in the event of an accident. The FAA now receives about 100 reports a month from pilots who say they've seen drones flying near planes and airports, up dramatically from last year. So far there've been no accidents, but agency officials have said they're concerned that even a small drone might cause serious damage if it is sucked into an engine, smashes into an airliner's windshield or collides with a helicopter's rotors. Helicopters are the greatest concern because they frequently fly below 500 feet in the same airspace as small drones, said Jim Williams, the FAA's former top drone official now at an international law firm with drone-industry clients. There are no studies on how much damage drones of different weight might cause to a helicopter or aircraft engine, he said. "I am not a fan of the weight limit because there's no science behind it," Williams said. The weight threshold for drone registration in Europe is about 2 pounds, while Canadian officials are leaning toward a threshold of about 1 pound, industry officials said. Williams said he hopes the FAA will add other requirements to the half-pound threshold that would eliminate most toys from the registration requirement. For example, many drones can navigate independently rather than relying on the operator to be constantly steering, Williams said. Operators can preset waypoints to fly a drone beyond their line of sight. If the waypoints are incorrectly set for an altitude or location where manned aircraft fly, "that's where the risk really comes from," he said. Williams said drones that can download real-time video are also a concern, because the operator becomes engrossed in the picture and is distracted.