Amazon.com Inc has filed for a patent to use airships to store products and serve as a base for delivery-drones. According to the patent filing, drones launched from the so-called "airborne fulfilment centres"would use far less power than those launched from the ground. The AFCs would hover at about 45,000 feet and be restocked and resupplied by "shuttles or smaller airships." Amazon has laid out plans to start using drones for deliveries next year.