Amazon has been awarded a patent for an “airborne fulfillment center” (AFC) that would act as a flying warehouse for its Prime Air delivery drones. The patent says the AFC would remain 45,000 feet in the air, and drones “with ordered items may be deployed from the AFC to deliver ordered items to user designated delivery locations.”

Smaller shuttles could deliver more inventory to the flying warehouse and transport employees, according to the patent. Amazon filed for the patent on December 22, 2014 and received the patent on April 5, 2016. CB Insight first reported the news.

One of the main benefits of the AFC, Amazon says, is that it can fly to different areas where the weather is better or expected/actual demand is higher. The patent uses a football game as an example, saying demand in that area for sporting paraphernalia or food could be much higher. The AFC could then re-locate to the area where the game is being played and deploy the delivery drones from there to more easily satisfy the increased demand.

Another benefit, according to Amazon, is that the power required to make drone deliveries is significantly reduced. Amazon has explored other ways to get around the short flight time of drones, including using street lights and church steeples as docking stations, but this AFC would also solve the problem of short battery life.

“Rather than the UAV having to operate at power from the time it departs the materials handling facility to the delivery location and back to the materials handling facility (or another location), the UAV may be deployed from the AFC and descend under the forces of gravity toward a delivery location using little to no power,” the patent says. “Only as the UAV approaches earth does it need to fully engage the UAV motors to maintain flight and complete delivery of the item.”

Drone delivery will be a main topic during our “Delivery Robots Knocking at Your Door” panel at the CES Robotics Conference that will explore how drones and autonomous mobile robots are transforming home delivery and emergency medical response. Ahti Heinla of Starship Technologies, Helen Greiner of CyPhy Works and Steve Cousins of Savioke will discuss developments, the need for continued testing and how to overcome regulatory and technical challenges.

Amazon Prime Air, which was first announced in 2013, made its first delivery on December 7, 2016. An Amazon Prime Air drone delivered an Amazon Fire TV and a bag of popcorn to a customer in Cambridgeshire, England. Amazon says the entire process, from the time the order was made online to the time the package arrived at the customer’s home, took 13 minutes. It was later revealed that the distance of the delivery was just 765 yards.

So it took Amazon a while to make its first Prime Air drone delivery, so it will be quite some time before you see an Amazon AFC in the sky. Of course, many patents never turn into actual products, so you may never see an Amazon AFC. But it’s certainly fascinating to see the online retail giant searching for ways to overcome some of the problems associated with drone delivery.

Other challenges facing the drone delivery industry are flights beyond the visual line of sight (BVLOS) and flying over populated areas. There is some progress being made on both those fronts, however, especially regarding BVLOS flights. The Federal Aviation Administration (FAA) approved a certificate of authorization (COA) for the Northern Plains UAS Test Site to conduct BVLOS flights.

The North Dakota test site is the first in the nation to be approved for BVLOS flights. Nick Flom, director of the Northern Plains UAS Test Site, told Robotics Trends that the approval initially applies to larger drones that can fly above 10,000 feet, but that the concept could make its way down to smaller drones used for lower-altitude operations, including delivery drones.