DJI

Using drones for business purposes just got a smidgen less illegal in the United States.

The Federal Aviation Administration announced on Tuesday new exemptions permitting five companies to operate their unmanned aircraft. The move marks an expansion of the uses the FAA permits and helps to set a pattern for other companies seeking the regulator's permission.

Drones, held aloft with multiple helicopter-like rotors and often equipped with a camera, are a hot technology item. Hobbyists have been snapping them up as a new aerial cousin to remote-controlled cars and boats. The FAA prohibits business use of the aircraft for the time being, though there's abundant demand to do everything from monitor construction sites or assist in marine salvage operations.

The FAA is gradually loosening up, though. In September, the FAA granted exemptions to drones in the movie and video industry; later came exemptions for real estate photography, agricultural monitoring and aerial surveying. Now another industry has been added to the list with an exemption that lets a company called Total Safety inspect flare stacks, the large towers used in the petrochemical industry sites like oil refineries to burn off undesired gases. Getting humans to the tops of these stacks is expensive, but drones can do it cheaply and even when the stack is operating. The other exemptions were for companies in categories the FAA had already started permitting: surveying and video for the entertainment industry.

The FAA's decisions will help determine how rapidly drones are embraced for business purposes -- and whether the drone industry takes its next, more ambitious steps in the United States at all.

Among the more contentious cases is e-commerce giant Amazon, which so far hasn't prevailed in its quest for an exemption and which is threatening to move its drone delivery research to another country. Google's drone delivery research project is taking place in Australia.

Later this year, the FAA plans to release draft regulations for comment that would permit broad use of relatively lightweight drones weighing less than 55 pounds. Until those regulations are done -- a September deadline seems improbable in the eyes of many observers -- the only way to get permission is through specific exemptions under a regulation called Section 333.

So far, the FAA has granted two dozen exemptions, and this month it also loosened restrictions for two granted last year. As the FAA adds more exemptions, it in effect sets a template for other petitioners who want an exemption by showing requirements like flying altitude limits and pilot licensing for drone operators. More recent exemptions also opened the door for mainstream drones such as drone maker DJI's Phantom models.

The floodgates haven't exactly opened, though, and offering broader drone regulations is a tricky task, FAA spokesman Les Dorr said. The agency has been working since 2009 on "writing a rule that's going to maintain today's extremely high level of safety but won't put undue regulatory burden on an evolving industry," he said.

The agency had planned to publish its draft regulations in 2014 but missed that deadline. After they are published, the agency plans a 60-day public comment period, then some time to consider those comments and potentially update the regulations in response.

As for Amazon -- perhaps the highest-profile drone advocate -- Dorr said it's possible the regulator could come to some kind of accommodation under the current exemption process.

"We are working with them to figure out what sort of authorization would work best with them," Dorr said.