It may look sort of like a lawnmower, but this aircraft from an Austrian research company uses rapidly spinning cylinders with airfoils inside to hover and maneuver just like a helicopter.
IAT21's D-Dalus vehicle doesn't look like it should be able to fly at all, but its designers say that it's poised to take over for the helicopter, offering all the same vertical take-off, hovering, and maneuverability advantages without the disadvantages of having giant spinning rotor blades to watch out for.
Those cylinders that you can see in the picture spin around at 2,000 RPM, and inside are arrays of wing-like blades. These blades can be moved to change their angle of attack inside the cylinders, such that they are able to generate thrust in any direction.
The vehicle can take off vertically, rotate in place, move backwards, and even thrust downward, which comes in handy if you're trying to land on, say, a ship in bad weather. It's far quieter than a helicopter, and it's ideal for maneuvering close to obstacles since it doesn't have any external moving parts.
The most obvious and immediate application for D-Dalus is as a little flying spy robot that can fly in doors and windows and snoop around indoors. Larger versions would be perfect for search and rescue missions, and the designers even think that in the long term, vehicles based on this technology might be what you use to commute to work. That's right — flying cars!