Airports and bases that currently host drones are already scattered across the country. Here is a look at the 110 places that plan to host drones by 2017.

Civilian drone incidents are also rising. Public agencies have reported 23 accidents involving authorized drones since 2009. And the FAA says pilots have reported 15 close calls with small rogue drones near airports in the past two years.

Accident investigation documents show that 47 military drones crashed in the United States between 2001 and 2013 in what the military categorized as Class A accidents — the most severe category. The Pentagon is planning to expand drone operations to at least 110 bases in 39 states by 2017.

The problem is worsening just as the federal government is preparing to lift barriers that could flood the country’s already congested skies with thousands of remotely controlled aircraft. Under a law passed two years ago, Congress ordered the FAA to issue rules legalizing drones for commercial purposes by September 2015 — the first step in a new era of aviation that will eventually allow drones of all sizes to fly freely in the national airspace, sharing the same airports as regular planes.

Congress imposed dual mandates on the FAA that the agency has struggled to reconcile. Under the law, the agency must draft rules for drones as soon as possible so businesses can exploit their economic potential. The FAA must also ensure that safety standards are not compromised and passenger aircraft are not imperiled.

The FAA is facing pressure to move faster from drone manufacturers, the military, members of Congress and many companies that see remotely controlled airplanes as a breakthrough technology. The drone industry complains that it is losing $27 million in economic benefits a day while the FAA prepares regulations for certifying drones and licensing pilots.

The FAA says it is moving as quickly as it can.

“I completely understand that there is significant potential, there’s significant benefit, there’s great things that unmanned aircraft can do. We need to be convinced that they can do so safely,” Michael P. Huerta, the FAA’s administrator, said in an interview.

“Every day in America people are getting on airplanes. Every day people are seeing airplanes in the sky,” Huerta added. “But they’re not really worried a lot about whether it’s safe. It’s their expectation that these things, that unmanned aircraft flying around in our airspace, will meet that same level of safety. And we owe that to them.”

The longer the FAA takes to finalize its rules, the more rogue drones are taking to the skies.

Thanks to rapid advances in technology, small satellite-guided drones with powerful miniature cameras can be bought online for less than $500. Flying drones as a hobby is permitted as long as operators keep them below 400 feet, away from populated areas and at least three miles from an airport, according to the FAA. But those restrictions are being flouted and ignored.

On May 5, a quad-copter — a drone with four rotors — crashed into the 30th floor of St. Louis’s Metropolitan Square building, the city’s tallest. In March, the FAA fined a Brooklyn man $2,200 for striking two midtown Manhattan skyscrapers with his quad-copter before it nearly hit a pedestrian. In August, a small drone with multiple rotors crashed into the grandstand at Virginia Motorsports Park in Dinwiddie County, injuring three spectators.

Even drone advocates worry that the skies are becoming a free-for-all.

“We have to understand that the industry is at risk because of illegal drone usage,” Krista M. Ochs, a General Dynamics executive, said last month at a drone-industry conference in Orlando. “If we have a major catastrophe that involves some type of midair collision, it could set us back years.”

Overwhelmed regulators?

In 2012, Congress passed the FAA Modernization and Reform Act, legislation that ordered the federal government to “safely accelerate” the integration of civilian drones into the busiest airspace in the world.

At the time, the military had been flying drones overseas for more than a decade, revolutionizing warfare by keeping pilots on the ground and out of harm’s way. Defense contractors who invented the technology saw even bigger potential to sell drones to private businesses and other government agencies. Industry groups projected a market with $8 billion in annual revenue.

Until then, the FAA had been moving slowly and cautiously, issuing a handful of permits for the military, law enforcement agencies and universities to fly drones under restrictive conditions. The new law ordered the FAA to hurry it up. Lawmakers set a deadline of Sept. 30, 2015, for the FAA to develop a comprehensive plan and allow civilian drones to begin flying on a more regular basis.

The FAA has approved six sites across the country to test drones and produce data that will shape safety standards. Officials said they will first propose rules for drones weighing 55 pounds or less. Regulations for larger aircraft will take significantly longer. Both sets of rules could take years to finalize. In an interim step, FAA officials say they may grant permits to filmmakers, farmers, and the oil and gas industry to use small drones under limited circumstances.

Manufacturers of drones and businesses that want to buy them are losing patience. They warn that foreign companies will steal the market if the FAA does not act swiftly. “We have got to be able to understand what the standards must be, and we have got to start fielding this technology,” Michael Toscano, president and chief executive of the drone industry’s trade association, said in a May 30 speech to the Aero Club in Washington.