It's been more than a year in the making, but it seems that the regulatory wheels are beginning to turn on Amazon's bold plan for drone deliveries. The FAA has today granted the online retailer permission to start testing its unmanned aircraft as part of its Prime Air initiative. It does come with its share of caveats, however, so don't expect a box set to be air-delivered to your doorstep anytime soon.

Amazon CEO Jeff Bezos first unveiled plans to use drones to deliver small packages in late 2013, saying that "we hope the FAA's rules will be in place as early as sometime in 2015. We will be ready at that time." But since then, Amazon has played the waiting game as the Federal Aviation Administration (FAA) revamps its regulations for unmanned aerial vehicles.

With progress slow-going, the FAA has faced mounting pressure from many quarters, but in particular Amazon, which has threatened to take its drone operations off-shore. This sentiment boiled over in December as the FAA gave four companies permission to use drones in commercial operations, adding to the four Hollywood companies who had been cleared to use them for film production in September. Amazon made public a letter to the FAA claiming that "we are very concerned that our needs for testing operations have not yet been accommodated."

So today's development will certainly be welcome news, but won't have Bezos selling off his delivery trucks for high-flying counterparts just yet. The FAA has issued Amazon with what it calls an "experimental airworthiness certificate." The rules laid out by the certificate are in line with what we've come to expect from the earlier approvals granted by the FAA, and also the set of proposed guidelines it floated last month.

Amazon's drones must be flown at 400 ft (122 m) or lower during daylight in clear conditions. The drones must remain within the line-of-sight of the pilot and he or she must have a private pilot's certificate and current medical certification. As part of the approval, Amazon is also required to give the FAA monthly reports on its operations. This is to include the number of flights, pilot duty log times, any technical mishaps, deviations from air traffic controllers' instructions and breakdowns in communications links.

Source: FAA