This month, online retail giant unveiled a plan to use small drones to deliver packages weighing no more than 5 pounds into customers' hands in half an hour or less. It was the first time that a big-name retailer offered a compelling vision for using the technology.

Although drone technology has evolved, many questions remain, including safety and privacy concerns. The FAA has said that remotely piloted aircraft aren't allowed in national airspace on a wide scale because they don't have an adequate "detect, sense and avoid" technology to prevent midair collisions.

The test sites will work toward accomplishing that goal, which had been a concern of the Air Line Pilots Assn., the world's largest pilot union that represents nearly 50,000 pilots. The group said drones should be integrated into national airspace only after it could be shown that the aircraft, pilots and operators meet the same high standards as other commercial aircraft operations.

The Assn. for Unmanned Vehicle Systems International, a drone trade group, has long touted the economic benefits of the proliferation of the technology. The association issued a study last year that found, as a result of the existing aerospace infrastructure in the state, California is positioned to create more than 12,000 jobs and realize an economic impact of $2.39 billion in just the first three years after integration.

There are other hurdles as well. The prospect of robotic aircraft flying over communities has generated cries of spies in the skies — and prompted legislation from city halls to Congress to restrict their operations.

The FAA said Monday that test-site operators will be required to obey laws protecting an individual's right to privacy. But ACLU staff attorney Catherine Crump said that the FAA's requirement that test sites have privacy policies was not enough.

"Someday drones will be commonplace in U.S. skies and, before that happens, it's imperative that Congress enact strong, nationwide privacy rules," she said.

Selected as the test site operators were the University of Alaska, which will work with groups in Hawaii and Oregon to conduct testing in those states too; Griffiss International Airport in upstate New York; North Dakota's Department of Commerce; Texas A&M University in Corpus Christi; and Virginia Tech, which also will be testing with groups in New Jersey.

The first testing site is expected to be up and operating in 180 days.