Collective detent system for vertical takeoff flight operations

A collective detent system for a flight control system of a helicopter for use in helicopter flight operations, including a vertical takeoff flight profile, comprising:

• a collective control stick that is pivotable through a range of operating positions from a full-down collective position to a full-up collective position, one of said operating positions of said range being defined as a vertical takeoff operating position for the vertical takeoff flight profile of the helicopter;
• a trim switch that is operative to generate a first trim signal when activated and a second trim signal when deactivated;
• a vertical takeoff detent switch that is operative to generate a detent signal when activated;
• a sensor that is operative to detect pivotal movement of said collective control stick into said vertical takeoff operating position and to generate a stick-position signal in response to detecting said collective control stick in said vertical takeoff operating position;
• and
• a restraint force generating device that is
• automatically energized in response to said detent signal and said stick-position signal to exert a restraint force on said collective control stick,
• de-energized in response to said first trim signal such that said restraint force is not exerted on said collective control stick such that said collective control stick is freely pivotable through said range of operating positions, and
• energized in response to said second trim signal to exert said restraint force on said collective control stick;
• and wherein
• said vertical takeoff detent switch is activated prior to initiating the vertical takeoff flight profile in the helicopter to generate said detent signal;
• said sensor generates said stick-position signal when said collective control stick is pivoted into said vertical takeoff operating position;
• and
• said restraint force generating device, in response to said detent signal and said stick-position signal, exerts said restraint force on said collective control stick to detain said collective control stick in said takeoff operating position and to impede movement of said collective control stick out of said vertical takeoff operating position during the vertical takeoff flight profile of the helicopter;
• and wherein
• said trim switch is activated to generate said first trim signal to de-energize said restraint force generating device so that said restraint force is not exerted on said collective control stick wherein said collective control stick is freely pivotable through said range of operating positions to a selected operating position during helicopter flight operations;
• and wherein
• said trim switch is deactivated to generate said second trim signal to energize said restraint force generating device so that said restraint force is exerted on said collective control stick to detain said collective control stick in said selected operating position and to impede movement of said collective control stick out of said selected operating position during helicopter flight operations.

A method for effecting a vertical takeoff flight profile in a helicopter, comprising the steps of:

• (a) providing a collective detent system integrated in combination with a helicopter flight control system, said collective detent system including a collective control stick that is pivotable through a range of operating positions from a full-down collective position to a full-up collective position with one of said operating positions defining a vertical takeoff operating position that provides the vertical takeoff power level required for the vertical takeoff flight profile of the helicopter, a vertical takeoff detent switch that is operative to generate a detent signal when activated, a sensor that is operative to generate a stick-position signal when said collective control stick is pivoted into said vertical takeoff operating position, a restraint force generating device that is operative in response to said detent signal and said stick-position signal to automatically exert a restraint force against said collective control stick, and a modified trim system circuit that functionally interconnects said vertical takeoff detent switch, said sensor, and said restraint force generating device in interactive combination;
• (b) activating said vertical takeoff detent switch to generate said detent signal prior to pivoting said collective control stick into said vertical takeoff operating position;
• (c) detecting the pivotal movement of said collective control stick into said vertical takeoff operating position and generating said stick-position signal in response to said detection;
• and
• (d) automatically exerting said restraint force against said collective control stick to electro-mechanically "detain" said collective control stick in said vertical takeoff operating position and to impede manual movement of said collective control stick out of said vertical takeoff operating position.