The turn of the first and second millennium brought development of many technologies. One of these technologies are unmanned aerial vehicles. Success in armies meant an expansion into the civil sector. Requirements for rapid installation into an armament and costs as low as possible meant the usage of current aircraft engines without any further modifications. Especially in an effort to achieve maximal altitude of the vehicle the engine without the modification could be a cause of unsuccessful effort of exploitation of vehicle´s options. Simple analyses of the vehicles and their current propulsion systems were found significant elements of their interconnections. Then the currently appropriate propulsion systems were assigned with a choice ...