As UAVs go, those that are basically powered gliders, are cheaper and more in demand than those that are based on helicopter technology. But helicopter type UAVs are constantly being requested, by combat troops, for urban fighting. While it's useful to gave a winged UAV circling above, sending down a "God's eye view" video, what the troops often need more is something that can come lower and just hover. Responding to this, and demand from police and other potential civilian users, manufacturers are producing more helicopter type UAVs. For example, there's the fifty pound Autocopter. With a 6.5 foot diameter rotor, this UAV can carry 15 pounds of equipment. This can include the usual array of cameras, plus weapons. Currently, an automatic shotgun has been rigged up for the Autocopter. The UVA can stay up about 50 minutes per sortie. Range is about 2.5 kilometers (although with additional communications gear, that can go to 30 kilometers). Am emergency parachute is carried, to save the UAV in case of engine failure. That's helpful, as these UAVs cost about $100,000 each. The flight software is exceptionally good, meaning that all the operator has to do is point and click, or wield a joystick, to get Autocopter where it's needed. There are even smaller helicopter UAVs in development, as what the troops want is something small, and silent (or at least battery powered and very quiet), to flit about and check out what's around the corner and down the street.