Delivery Drones Use Bird-Inspired Legs to Jump Into the Air

Drones have a fundamental design problem. The kind of drone that can carry large payloads at high speeds over long distances is fundamentally different from the kind of drone that can take off and land from a small area. In very simple terms, for the former, you want fixed wings, and for the latter, you want rotors. This problem has resulted in a bunch of weird drones that try to do both of these things at once, usually by combining desired features from fixed-wing drones and rotorcraft. We've seen tail-sitter drones that can transition from vertical take off to horizontal flight; we've seen drones with propeller systems that swivel; and we've seen a variety of airframes that are essentially quadrotors stapled to fixed-wing aircraft to give them vertical take-off and landing capability.