The Federal Aviation Administration (FAA) has published rules that loosen restrictions on low-level small drones for education and research purposes, although companies like Amazon will still not be free to start drone delivery services, unless new rules related to commercial drones are released.

http://www.faa.gov/uas/media/Part_107_Summary.pdf

The rules, scheduled to take effect in late August, include the requirement that drones be kept within line of sight of the operator at all times. Unmanned commercial aircraft deliveries from companies like Amazon.com and Alphabet will require separate regulation. The head of the U.S. Federal Aviation Administration, Michael Huerta, declined to offer a timetable on when those separate rules would be written. Until now, commercial drone operations had been illegal in the United States without specific FAA permission.

As part of the rules, drones will be allowed to fly until the twilight if the drone has anticollision lights.Their weight shopuld be less than 55 pounds (25 kg) and they should fly up to 400 feet (122 m) high and 100 miles per hour (161 km per hour).

The rest of the ruls remain the same: drones cannot operate over people not associated with the flight; and must yield to other aircraft. They also spell out where the drone can fly. Operations are allowed within most airspace with air traffic control clearance, but never around major airports.

To operate a drone for commercial use, the FAA will require some knowledge of the rules of the sky, either through a remote pilot certificate, which is a new certification the agency is preparing, or a student private pilot's license.

In contrast, hobbyists can fly drones without either of the two licenses.