Abstract: An unmanned aircraft includes a forward propulsion system comprising one or more forward thrust engines and one or more corresponding rotors coupled to the forward thrust engines; a vertical propulsion system comprising one or more vertical thrust engines and one or more corresponding rotors coupled to the vertical thrust engines; a plurality of sensors; and a yaw control system, that includes a processor configured to monitor one or more aircraft parameters received from at least one of the plurality of sensors and to enter a free yaw control mode based on the received aircraft parameters.

Abstract: An unmanned aircraft includes a forward propulsion system comprising one or more forward thrust engines and one or more corresponding rotors coupled to the forward thrust engines; a vertical propulsion system comprising one or more vertical thrust engines and one or more corresponding rotors coupled to the vertical thrust engines; and a pitch angle and throttle control system, comprising a processor configured to receive a first pitch angle command; and generate a second pitch angle command and a forward thrust engine throttle command based on a bounded pitch angle for the aircraft.

Abstract: An unmanned aircraft includes a forward propulsion system comprising one or more forward thrust engines and one or more corresponding rotors coupled to the forward thrust engines; a vertical propulsion system comprising one or more vertical thrust engines and one or more corresponding rotors coupled to the vertical thrust engines; and a pitch angle and throttle control system, comprising a processor configured to receive a first pitch angle command; and generate a second pitch angle command and a forward thrust engine throttle command based on a bounded pitch angle for the aircraft.

Abstract: An aircraft, such as an unmanned aircraft, can include a forward propulsion system comprising one or more engines and one or more rotors coupled to a corresponding engine; a vertical propulsion system comprising one or more vertical propulsion engines and one or more corresponding rotors coupled thereto; a sensor package comprising one or more sensors to detect an operating parameter of the aircraft. It may further include an automatic recovery system that includes an input coupled to the sensor package; an output coupled to an aircraft controller; a processor to monitor one or more operating parameters of the aircraft, detect a failure of the forward propulsion system based on the operating parameters, and transition the aircraft to the vertical propulsion system for landing.

Abstract: An unmanned aircraft includes a forward propulsion system comprising one or more forward thrust engines and one or more corresponding rotors coupled to the forward thrust engines; a vertical propulsion system comprising one or more vertical thrust engines and one or more corresponding rotors coupled to the vertical thrust engines; a plurality of sensors; and a yaw control system, that includes a processor configured to monitor one or more aircraft parameters received from at least one of the plurality of sensors and to enter a free yaw control mode based on the received aircraft parameters.

Abstract: An unmanned aerial vehicle (UAV) survey system and methods for surveying an area of interest are disclosed. The system can include a plurality of docking stations positioned at predetermined locations within the area of interest, each docking station comprising a platform to support a UAV while docked at the docking station; a battery charger; and a communications interface; a plurality of UAVs distributed among the plurality of docking stations, each UAV comprising a communications interface; and a system controller comprising a processor and transmitter communicatively coupled to the plurality of UAVs.

Abstract: A vertical take-off and landing aircraft includes a fixed wing airframe having opposed left and right wings extending from left and right sides, respectively, of a fuselage having opposed leading and trailing extremities and an empennage located behind the trailing extremity. Four fixed, open and horizontal, vertical take-off and landing (VTOL) thrust rotors are mounted to the airframe in a quadrotor pattern for providing vertical lift to the aircraft, and a vertical, forward thrust rotor is mounted to the trailing extremity of the fuselage between the trailing extremity of the fuselage and the empennage for providing forward thrust to the aircraft. The four VTOL thrust rotors are coplanar being and operating in a common plane that is parallel relative to, and being level with, top surfaces of the left and right wings in and around a region of each of the four VTOL thrust rotors.