Abstract: A portable multithruster unmanned aircraft for search and rescue missions, including avalanche beacon position/detection, as well as military field operations such as “forward observer” deployment is disclosed. In one aspect, the aircraft includes four rotor assemblies, housed in cowlings, deployably stowed in a cylindrical airframe to present a smooth surface for portability in tight quarters, such as a backpack, duffle bag or the like. The rotor assemblies, upon activation, are deployed by mechanical or electromechanical means to operating, flight ready position, exterior the airframe through slots in the skin of the airframe or by unfolding the hinged cowlings nested within the airframe. In one aspect, four deployed rotor assemblies are quadrantally positioned about the airframe, preferably in a horizontal plane perpendicular to the vertical axis of the airframe. A payload, including a power source, is contained within the cylindrical airframe for operation, including navigation.