Hybrid powered unmanned aircraft system

An unmanned aircraft system having a vertical takeoff and landing flight mode and a forward flight mode, the unmanned aircraft system comprising:

• an airframe;
• a rotor assembly including at least two rotor blades having a tip jet, the rotor assembly rotatably coupled to the airframe;
• a compressed gas power system operably associated with the tip jets, the compressed gas power system including a compressed gas canister and a valve for selectively releasing the compressed gas from the compressed gas canister;
• a propeller rotatably coupled to the airframe;
• an electric power system operably associated with the propeller;
• a flight control system operable to control the compressed gas power system and the electric power system;
• and
• a sensor system coupled to the airframe;
• wherein, in the vertical takeoff and landing flight mode, compressed gas from the compressed gas power system is discharged through the tip jets to rotate the rotor assembly to generate vertical lift;
• and
• wherein, in the forward flight mode, the electric power system drives the propeller to generate forward thrust and autorotation of the rotor assembly generates vertical lift.