As the number of firms approved to commercially operate unmanned aircraft systems in the U.S. increases, so do these companies' UAS demands, leading some to seek experienced European manufacturers or partner with automated-flight firms.

Getting approval under Section 333 of the 2012 Federal Aviation Administration's Modernization and Reform Act isn't the easiest thing, says Russ Metzler, director of UAS services at Asymmetric Technologies, Columbus, Ohio. "It's not egregious but a little frustrating," he says. "You search the 333 document and find the parts that apply to you and justify why you can meet them. Then, you present to the FAA why you are a low risk." Then, you wait, he says. The service-disabled, veteran-owned firm got its exemption to do bridge inspection, but its niche is infrastructure inspection in a broader sense, looking into power, civil and dam inspection says Brian Borkowski, Asymmetric's president and CEO. "I'm not trying to replace inspectors but, rather, give them a tool in their toolbox," he says.

The number of providers that legally can offer that tool is growing. At present, 189 firms are approved to commercially use UAS technology in the U.S.

Bechtel Corp., San Francisco, recently made the list. "Drones are interesting to us in two aspects: safety and process," says Mike Lewis, Bechtel's global manager of construction. He says using a UAS to explore extreme heights, confined spaces and areas with dangerous material, without direct human involvement, reduces risks for Bechtel workers. To increase safety while adopting a new tool, Bechtel partnered with Skycatch Inc., San Francisco, in 2013.

"Their unique platform is connected to a cloud for real-time analytics and has preprogramed geographic controls for safe operation and compliance with flight announcements," says Lewis.

For safety and performance reasons, Asymmetric also chose a different path than buying a drone on

"We want to safely capture usable data when we're up close to a structure," says Metzler. "It takes a professional aircraft to do that." Metzler says he spent a year and a half looking at every UAS manufacturer in the U.S. and had to go overseas to find one that met his criteria.

"That speaks to the backward state of the U.S. drone environment," he says. FAA regulations limited investment in the U.S. commercial drone space until recently. The dearth of investment led to a U-shaped development curve, with the hobbyist on one side and expensive military-grade platforms on the other, he says.

Asymmetric chose the md4-1000 UAS from Microdrones, Siegen, Germany. It has an 88-minute flight time and carries a 2.2-lb payload.

"It was a far superior choice," says Metzler. "This bird has five to six years of actually doing what it claims in Europe and Asia." The advanced German drone isn't necessary for contractors that take photos for only site progress—the DJI Phantom and other sub-$1,000 drones can do that. But when flying a few feet away from worker-filled structures, wind, stability, control and safety are the most important concerns, says Borkowski.

"People are starting to understand that this is a safe tool," he says.