reinventing the wheel, uh, rotor
The US Military has been using autonomous helo-based drones - primarily the K-Max but also Bell 206L Longrangers, Bell 407s and Hughes/Boeing MD6s - to deliver cargo and (allegedly) self-loading cargo of the SpecOps variety to locations around Afghanistan for some years now. If *they* can do it under combat conditions, maybe UPS should be outsourcing their deliveries to Uncle Sam?
At least then there would be a reasonable explanation for why so many packages seem to have free-fallen from about 5000 ft.