There are now more registered drone owners in the United States than there are other kinds aircraft, according to new figures from the Federal Aviation Administration.
Almost 460,000 drone owners have registered with regulators, the FAA reports. Owners are required to register only once, even if they own more than one drone, so the actual number of unmanned aircraft is likely to be larger.
By comparison, there are about 315,000 aircraft logged in the FAA's main aircraft database.
There are 2,806 aircraft in Maryland, according to the FAA's main registry, and 9,259 drone owners.
The largest numbers of drone owners in the state are in suburban areas around Baltimore and Washington.
The ZIP code with the greatest number of drone pilots is 21122, which covers the Pasadena area, with 148. But there are also clusters of drone ownership in St. Mary's County in Southern Maryland, which has emerged as a center for testing the unmanned aircraft, and Salisbury on the Eastern Shore.
The FAA began requiring drone owners to submit data for a registry shortly before Christmas and released the numbers this month. Any drone pilot or model aircraft owner with a vehicle that weighs between 0.55 pounds and 55 pounds is required to register using an online form.
As drones have become a popular toy, giving users an inexpensive way of gathering aerial pictures and video footage, regulators have been struggling to figure out how to keep track of them.
Many models can fly high and far beyond the operator's line of sight, where they risk collisions with airplanes and helicopters.
A process for determining rules for the commercial use of drones is moving forward slowly, frustrating would-be entrepreneurs who see business opportunities in the aircraft. Just 159 of the drone owners in Maryland registered as "non-hobbyist" users, according to the FAA.
Eric DiProspero, the president of Federal Hill drone company Heights + Horizons, said the FAA figures underscore how far the commercial use of drones has to go before becoming mainstream.
"The industry looks at drones as a hobby, as a toy, when in reality there are sustainable commercial enterprises that are using these on a daily basis," DiProspero said. "It falls on the FAA to open up and listen to folks reasonably, but it also falls on drone users, whether it's hobbyist or commercial, to do so responsibly to not force the FAA's hand."
The FAA said it released the data in response to Freedom of Information Act requests. The agency declined to release the full data — including names and addresses of registrants — because officials determined it would be an invasion of people's privacy.
That contrasts with registration records for regular aircraft, which are highly detailed and easily searchable on the FAA's website.