Britain's aviation regulator said Tuesday that it would allow drones to inspect infrastructure such as power lines and wind turbines, a move the authority has described as a significant milestone.

The U.K.'s Civil Aviation Authority (CAA) had said earlier this year that it wanted to permit more drone flying for such activities as well as for deliveries and emergency services. It selected in August six projects to test it.

Drones inspecting infrastructure will now be able to fly distances beyond remote flyers' ability to see them.

"While some drones have been flying beyond visual line of sight in the U.K. for several years, these flights are primarily trials under strict restrictions," the CAA said.

Under the CAA's new policy, some drones will be able to remain at low heights close to infrastructure where there is little or no potential for any other aircraft to operate. It will also reduce costs, the CAA said.

Drones will inspect power lines for damage, carry out maintenance checks of wind turbines and even be used as "flying guard dogs" for site security.

The CAA will work with several operators to test and evaluate the policy, which according to the regulator's director, Sophie O'Sullivan, "paves the way for new ways drones will improve everyday life."