Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.

An unmanned helicopter platform includes a fuselage, a tail coupled with the fuselage, a payload rail coupled with and extending along the fuselage and a main rotor assembly coupled with the fuselage. The tail includes a tail rotor and a tail rotor motor. The tail is removably coupled to the fuselage. The main rotor assembly includes a main rotor having an axis of rotation and a main rotor motor.

A remote control device for an unmanned helicopter includes an orientation sensor that detects a flight orientation of the unmanned helicopter, a GPS antenna and a GPS receiver that detect speed information of the unmanned helicopter, and a CPU that detects a flight distance of the unmanned helicopter by integrating the speed information. A memory stores information concerning a base point of the unmanned helicopter. Based on a flight orientation of the unmanned helicopter and a flight distance of the unmanned helicopter, which is obtained by integration of the speed information, the CPU determines a relative position, which indicates a position of the unmanned helicopter with respect to the base point, and controls the flight of unmanned helicopter based on the relative position.

A rocket or ballistic launch rotary wing air vehicle may include a rocket or ballistic launch propulsion system for launching the vehicle, a rotary wing flight system for providing powered flight comprising dual counter rotating coaxial rotors, and a control system programmed to adjust the pitch of a rotor to anyh determined degree of pitch independently of a flap angle of the flap hinge during a transition of the dual counter rotating coaxial rotors from a stowed position to a deployed position.

A radio controlled (RC) vehicle includes a receiver configured to receive a radio frequency (RF) signal from a remote control device. The RF signal indicates command data in accordance with a first coordinate system. The command data includes yaw-velocity command data. The RC vehicle includes motion sensors configured to generate motion data. The RC vehicle includes a processor coupled to the motion sensors and to the receiver. The processor is configured to transform the command data into control data based on the motion data and in accordance with a second coordinate system from a perspective of the RC vehicle. The control data includes yaw-velocity control data. The yaw-velocity control data is related to the yaw-velocity command data. The RC vehicle includes control devices coupled to the processor and configured to control motion of the RC vehicle based on the control data.

A method of performing a cooperative safe landing area determination includes receiving perception sensor data indicative of conditions at a plurality of potential landing areas. A processing subsystem of a vehicle updates a local safe landing area map based on the perception sensor data. The local safe landing area map defines safe landing area classifications and classification confidences associated with the potential landing areas. One or more remotely-generated safe landing area maps are received from one or more remote data sources. The one or more remotely-generated safe landing area maps correspond to one or more additional potential landing areas and non-landing areas. The local safe landing area map and the remotely-generated safe landing area maps are aggregated to form a fused safe landing area map. The fused safe landing area map is used to make a final safe landing area determination.

A system includes a signal monitor to monitor a time rate of change of a revolution per minute (RPM) trim signal that is received from an RPM command path to control a velocity of a helicopter rotor. An icing detector detects for the presence of ice accumulation on the helicopter rotor by comparing the time rate of change of the RPM trim signal to a predetermined threshold for the time rate of change.

A radio controlled (RC) vehicle includes a receiver that is configured to receive an RF signal from a remote control device. The RF signal contains command data in accordance with a first coordinate system that is from a perspective of the remote control device. A motion sensor is configured to generate motion data. A processor is configured to transform the command data into control data based on the motion data and in accordance with a second coordinate system that is from a perspective of the RC vehicle. A plurality of control devices are configured to control motion of the RC vehicle based on the control data.

Methods and systems for inspecting insulated equipment for corrosion under insulation are provided. The system includes an autonomous unmanned vehicle having aerial and ground locomotive capabilities. The vehicle includes an infrared detector and a pulsed eddy current sensor. In the method, infrared waves emitted from the equipment are detected along the equipment with the infrared detector. Using the infrared detector, at least one image of an inner surface of the equipment is developed based on the detected infrared waves. At least one area that is susceptible to corrosion is determined based on the at least one image. The susceptible area is inspected with the pulsed eddy current sensor, which induces an eddy current in the inner wall of the equipment. Based on a rate of the decay in strength of the eddy current, it is determined whether corrosion exists at the susceptible area using a processor configured by code.

Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.