Dual-channel deicing system for a rotary wing aircraft

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.

What is claimed is: 
     
         1 . A dual primary deicing system for a rotary-wing aircraft comprising:
 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.   
     
     
         2 . The dual primary deicing system as recited in  claim 1 , wherein said electrothermal heating element system includes a first electrothermal heating element, a second electrothermal heating element, a third electrothermal heating element, and a fourth electrothermal heating element for each main rotor blade of the main rotor blade assembly. 
     
     
         3 . The dual primary deicing system as recited in  claim 1 , wherein said heating cycle defines a second electric pulse train subsequent to said first electric pulse train. 
     
     
         4 . The dual primary deicing system as recited in  claim 3 , wherein said first pulse train communicates with a first main rotor blade and a second main rotor blade of said main rotor blade assembly, and said second pulse train communicates with a third main rotor blade and a fourth main rotor blade of said main rotor blade assembly. 
     
     
         5 . The dual primary deicing system as recited in  claim 4 , wherein said first pulse train and said second pulse train are sequentially communicated as said heating cycle. 
     
     
         6 . The dual primary deicing system as recited in  claim 1 , wherein said controller defines an off-time between heating cycles, and an element on-time within said first pulse train. 
     
     
         7 . The dual primary deicing system as recited in  claim 6 , further comprising an ice rate probe in communication with said controller, said off-time defined in response to said ice rate probe. 
     
     
         8 . The dual primary deicing system as recited in  claim 6 , further comprising an air data computer in communication with said controller said element on-time determined in response to an outside air temperature determined by an air data computer. 
     
     
         9 . The dual primary deicing system as recited in  claim 8 , further comprising a second controller in communication with a second ice rate probe and said controller in communication with said electrothermal heating element in response to failure of said first controller. 
     
     
         10 . The dual primary deicing system as recited in  claim 9 , wherein the air data computer is a first air data computer, and further comprising a second air data computer in communication with said second controller, said second controller in communication with said electrothermal heating element in response to failure of said first air data computer. 
     
     
         11 . The dual primary deicing system as recited in  claim 1 , wherein said electrothermal heating element system comprises a first electrothermal heating element, a second electrothermal heating element, and a third electrothermal heating element, said third electrothermal heating element is operated prior to said first electrothermal heating element, said first electrothermal heating element is operated prior to said second electrothermal heating element in response to the heating cycle defined by the first electric pulse train. 
     
     
         12 . A method of deicing a rotary wing aircraft comprising the steps of:
 (1) communicating a heating cycle to an electrothermal heating element system, the heating cycle defining a first electric pulse train associated with a first set of main rotor blades; and   (2) repeating the heating cycle after an off-time.   
     
     
         13 . A method as recited in  claim 12 , further comprising the step of:
 determining an element on-time for the first pulse train, the heater element on-time being a linear function related to outside air temperature (OAT).   
     
     
         14 . A method as recited in  claim 13 , further comprising the step of:
 determining the element on-time with an on-time value of 19 seconds at an OAT=−30 degrees C. and a value of 1 second at temperatures between 0 degrees C. and +5 degrees C.   
     
     
         15 . A method as recited in  claim 14 , further comprising the step of:
 determining the off-time of said step (2) in accordance with a non-linear function of liquid water content (LWC).   
     
     
         16 . A method as recited in  claim 12 , further comprising the step of:
 setting the element off-time equal to 60 seconds/LWC.   
     
     
         17 . A method as recited in  claim 12 , further comprising the step of:
 activating a multiple of electrothermal heating elements of the electrothermal heating element system in a sequential order, the multiple of electrothermal heating elements including a first electrothermal heating element located along a leading edge of the main rotor blade; a second electrothermal heating element located aft of the first electrothermal heating element along an upper surface of the main rotor blade; a third electrothermal heating element located aft of the first electrothermal heating element along a lower surface of the main rotor blade; and a fourth electrothermal heating element located aft of the third electrothermal heating element along the lower surface of the main rotor blade, the sequential order being the third electrothermal heating element, the first electrothermal heating element; the second electrothermal heating element; then the fourth electrothermal heating element.   
     
     
         18 . A method as recited in  claim 12 , wherein said step 1) further comprises the step of:
 communicating a second electric pulse train subsequent to the first electric pulse train, the first electric pulse train associated with the first set of main rotor blades and the second electric pulse train associated with a second set of main rotor blades.   
     
     
         19 . A method as recited in  claim 12 , further comprising the step of:
 redundantly communicating a heating cycle from a second subsystem of a dual primary deicing system to the electrothermal heating element system simultaneous with the heating cycle communicated from a first subsystem of the dual primary deicing system.   
     
     
         20 . A method as recited in  claim 19 , further comprising the step of:
 alternatively designating either the first subsystem or the second subsystem of the dual primary deicing system as the primary subsystem.   
     
     
         21 . A method as recited in  claim 20 , further comprising the step of:
 alternatively designating either the first subsystem or the second subsystem of the dual primary deicing system as the primary subsystem at each initiation of the dual primary deicing system.