E-commerce company Amazon has been awarded with an 'experimental airworthiness certificate' by the Federal Aviation Administration (FAA) on Thursday to test a delivery drone outdoors.

Amazon wants to practice its goal of sending packages to customers by air, even though it faces public concern about safety and privacy.

The permission was awarded to test drones in outdoor areas near Seattle, where one of Amazon's research and development labs is developing the technology.

The FAA issued the certificate to an Amazon business unit and its prototype drone, which would allow test flights over private, rural land in Washington state.

Seattle-based Amazon has to obtain a new certification in case it modifies the aircraft or flies in a different version.

However, an exemption from other flight restrictions has also been granted by the FAA to Amazon so that the experimental drone can conduct those flights.

Under the certificate, Amazon has to abide by several rules, including operating flights at 400 feet (120m) or below in the daylight. However, the company has asked for permission to fly at altitudes up to 500 feet (150m).

According to the FAA, the certificate seeks pilots to acquire a private pilot's certificate, as well as medical certification. Also, Amazon will be required to supply monthly data, such as the number of flights conducted, to the regulators.

The FAA's approval has advanced plans by the company and others to deliver packages using small, self-piloted aircraft.

Amazon Chief Executive Jeff Bezos has planned to deliver packages under a program dubbed 'Prime Air'. The company is developing drones that fly at speeds of 80km/h, operate autonomously and sense and avoid objects. Amazon also is working with NASA on an air-traffic management system for drones.