In looking to airships, Amazon draws upon a long technological tradition dating back to the 19th century, when some of the world's first self-propelled dirigibles were created.
Sending drones out from a ground-based facility requires substantial energy, the filing says, because the drone must have its propellers spinning constantly to stay aloft. What's more, having to make a return trip to the warehouse with no payload onboard could be a wasteful expense. By contrast, Amazon believes it could be more efficient to deploy drones from airships; the drones could float or glide most of the way down to earth by way of gravity, rather than using their own power.
The airships would have to be resupplied periodically, of course. Amazon envisions still more airships - smaller ones - that could shuttle more drones, products and other things needed to keep the airships functioning up to the larger carrier.
A diagram from Amazon's patent filing that shows how the whole system could work.
There's no word on when such a system might debut; an Amazon spokesperson didn't immediately respond to a request for comment. Some patents never even lead to actual products. But companies such as Facebook and Google have floated the use of airships and drones to beam Internet connectivity down to earth, so it was likely only a matter of time before Amazon began thinking about how to apply the same technology to its business.