Disconnecting a rotor

Abstract

According to one embodiment, a clutch may be coupled between a rotor system and a power train of a rotorcraft. The clutch may be operable to disengage the rotor system from the power train during operation of the power train. A clutch control system in communication with the clutch and include a rotorcraft condition sensor operable to sense an operating condition of the rotorcraft and a control unit operable to prevent the clutch from disengaging the rotor system from the power train if the operating condition of the rotorcraft fails to satisfy a predetermined criterion.

What is claimed is: 
     
         1 . A method of controlling disengagement of a rotor system from a power train of a rotorcraft, comprising:
 sensing an operating condition of the rotorcraft;   comparing the operating condition to a predetermined criterion; and   preventing disengagement of the rotor system from the power train whenever the operating condition fails to satisfy the predetermined criterion.   
     
     
         2 . The method of  claim 1 , wherein the rotor system is an anti-torque rotor system. 
     
     
         3 . The method of  claim 1 , wherein the rotor system is a tail rotor system. 
     
     
         4 . The method of  claim 1 , wherein the rotor system is a propeller system. 
     
     
         5 . The method of  claim 1 , further comprising allowing disengagement of the rotor system from the power train whenever the operating condition satisfies the predetermined criterion 
     
     
         6 . The method of  claim 5 , reengaging the rotor system whenever the operating condition of the rotorcraft no longer satisfies the predetermined criterion. 
     
     
         7 . The method of  claim 1 , wherein the operating condition fails to satisfy the predetermined criterion whenever a landing gear of the rotorcraft is supporting less than a predetermined weight. 
     
     
         8 . The method of  claim 1 , wherein the operating condition fails to satisfy the predetermined criterion whenever a throttle position associated with the power train exceeds a predetermined threshold. 
     
     
         9 . The method of claim.  1 , wherein the operating condition fails to satisfy the predetermined criterion whenever a collective position associated with at least one main rotor blade of the rotorcraft exceeds a predetermined threshold. 
     
     
         10 . The method of  claim 1 , wherein the operating condition fails to satisfy the predetermined criterion whenever a rotating component coupled between the power train and the clutch rotates faster than a predetermined threshold. 
     
     
         11 . The method of  claim 1 , wherein the operating condition fails to satisfy the predetermined criterion whenever the rotorcraft is operating in autorotation flight. 
     
     
         12 . The method of  claim 1 , further comprising providing a pilot warning indicating when the rotor system is disengaged. 
     
     
         13 . The method of  claim 1 , providing a pilot warning indicating that a proximity sensor has sensed an object near the rotor system. 
     
     
         14 . A rotorcraft, comprising:
 a body;   a landing gear coupled to the body;   a power train coupled to the body and comprising a power source and a drive shaft coupled to the power source;   a main rotor system coupled to the power train, the main rotor system comprising at least one main rotor blade;   a propeller system coupled to the power train, the propeller system comprising at least one propeller blade,   a clutch comprising a clutch input and a clutch output, the clutch input in mechanical communication with the power train and the clutch output in mechanical communication with the propeller system the clutch operable to engage or disengage the propeller system from the power train during operation of the power train; and   a clutch control system in communication with the clutch, the clutch control system comprising:
 a weight on gear sensor operable to sense a weight supported by the landing gear; and 
 a control unit operable to prevent the clutch input and clutch output from engaging or disengaging from each other in response to the weight on gear sensor sensing a weight indicative of whether the rotorcraft is on the ground. 
   
     
     
         15 . The rotorcraft of  claim 13 , further comprising a rotorcraft condition senor operable to sense an operating condition of the rotorcraft,
 wherein the control unit is operable to prevent the clutch input and clutch output from engaging or disengaging from each other in response to the operating condition failing to satisfy a predetermined criterion.   
     
     
         16 . The rotorcraft of  claim 15 , wherein the rotorcraft condition sensor comprises a throttle position sensor and the operating condition fails to satisfy the predetermined criterion whenever a throttle position associated with the power train exceeds a predetermined threshold. 
     
     
         17 . The rotorcraft of  claim 15 , wherein the rotorcraft condition sensor comprises a collective position sensor and the operating condition fails to satisfy the predetermined criterion whenever a collective position associated with the at least one main rotor blade exceeds a predetermined threshold. 
     
     
         18 . The rotorcraft of  claim 15 , wherein the rotorcraft condition sensor comprises a clutch input speed sensor and the operating condition fails to satisfy the predetermined criterion whenever the clutch input rotates faster than a predetermined threshold. 
     
     
         19 . The rotorcraft of  claim 15 , further comprising a pilot warning system operable to provide a pilot warning indicating that a proximity sensor has sensed an object near the propeller system.