Abstract: A dual primary deicing system for a rotary-wing aircraft, according to an exemplary aspect of the present disclosure includes, among other things, an electrothermal heating element system; and a controller in communication with said electrothermal heating element, said controller communicating a heating cycle to said electrothermal heating element system, said heating cycle defining a first electric pulse train associated with a main rotor blade assembly.

Abstract: A dual primary deicing system for a rotary-wing aircraft, according to an exemplary aspect of the present disclosure includes, among other things, an electrothermal heating element system; and a controller in communication with said electrothermal heating element, said controller communicating a heating cycle to said electrothermal heating element system, said heating cycle defining a first electric pulse train associated with a main rotor blade assembly.

Abstract: A dual primary deicing system for a rotary-wing aircraft, according to an exemplary aspect of the present disclosure includes, among other things, an electrothermal heating element system; and a controller in communication with said electrothermal heating element, said controller communicating a heating cycle to said electrothermal heating element system, said heating cycle defining a first electric pulse train associated with a main rotor blade assembly.

Abstract: A deicing system includes dual deice system components to provide a redundant deice system. Each redundant portion of the system generally includes a controller, an air data computer, an ice rate controller, and an ice rate probe. The controller communicating a heating cycle which defines a multiple of electric pulse trains to sequentially provides power to a multiple of heating elements in a designated blade set. Each electric pulse train is defined by an element on-time, a null time between the element on-time for this element and the next element, and an off-time between repetition of the heating cycle for the first heater element. The element on-time is a function of outside air temperature (OAT). The off-time is a function of liquid water content. The tail rotor heating cycle is a more straightforward version of the main rotor heating cycle as each of the tail rotor blade are activated simultaneously and there is only a single heating element on each tail rotor blade.

Abstract: An unmanned aerial vehicle (UAV) having a toroidal fuselage and a rotor assembly including counter-rotating rotors coaxially mounted with respect to the toroidal fuselage incorporates ancillary aerodynamic structures aerodynamically configured and mounted in combination with the toroidal fuselage to provide a nose-down pitching moment to counteract the nose-up pitching moment generated by airflow over the toroidal fuselage during forward translational flight of the UAV. The ancillary aerodynamic structures have a cambered airfoil profile to provide high lifting forces.

Abstract: An airfoil shaped cross section 36 for the rotor blade 14 is disclosed. Various construction details which improve the aerodynamic and drag performance of the airfoil section are developed. The upper surface 38 and the lower surface 42 are contoured by a thickness distribution and a camber distribution such that the bend of the surfaces is constant or changes at a constant rate over certain regions of the airfoil to avoid the formation of strong, normal shock waves at local Mach numbers less than 1.2 during normal, level flight conditions at standard temperature and pressure.