There are helicopter drones and fixed-wing drones, but creating a hybrid of both is tricky. Even Parrot's Swing, as clever as it is, needs four propellers and elaborate wings to pull off its stunt. However, TU Delft (with backing from Parrot) has a far more elegant solution. Its DelftAcopter drone doubles as both a fixed-wing aircraft and a helicopter using only one propeller -- its tailless biplane design lets it take off and hover vertically, but gracefully turn into a fast-moving airplane (up to 62MPH) at a moment's notice. It's an incredibly simple design that makes you wonder why someone hadn't considered it for drones before.