Helicopter Collective Pitch Margin Display for Power Limit Compliance
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Solution Overview
Problem
Existing rotorcraft piloting methods face challenges in accurately managing collective pitch during dynamic maneuvers, leading to potential engine overshooting of power limits, especially when pilots quickly maneuver the aircraft.
Innovation Solution
A method and device that utilize a recursive algorithm to calculate an optimized collective pitch margin by reducing the displayed margin relative to the real available margin, ensuring compliance with power plant limits, and optionally applying a power penalty or considering variations in rotor speed and air density, thereby providing accurate collective pitch limits during both stabilized and dynamic flight stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the collective pitch margin is displayed based on real available margin during dynamic maneuvers, then the pilot can maximize power utilization, but the engine may overshoot power limits due to regulator response delay
Solution Approach 1:
The system applies a power penalty factor to preemptively reduce the displayed collective pitch margin before the engine can overshoot its power limits. This anticipatory reduction compensates for the regulator's response delay during dynamic maneuvers, preventing harmful overshooting while still providing useful guidance to the pilot.
Solution Approach 2:
The system calculates and displays a reduced collective pitch margin in advance of actual power limit violations. By proactively adjusting the displayed margin downward during dynamic flight conditions, the system gives the pilot advance warning to moderate power requests before the engine reaches dangerous operating limits.
2Loss of information
If individual power plant parameter indicators are continuously displayed, then the pilot has complete information for monitoring, but the instrument panel becomes cluttered and complexity increases
Solution Approach 1:
The system merges multiple individual power plant parameter indicators (Ng, Cm, T45) into a single integrated collective pitch margin display. By combining these separate monitoring functions into one unified parameter that reflects the limiting factor, the system maintains complete monitoring capability while significantly reducing instrument panel clutter.
Solution Approach 2:
The collective pitch margin display serves multiple monitoring functions simultaneously, replacing the need for separate indicators for gas generator speed, drive torque, and turbine inlet temperature. This multi-functional display provides comprehensive power plant status information through a single parameter that adapts to different operating conditions.
Data Source
AI summary
A method of assisting the piloting of an aircraft, such as a helicopter, includes determining a limiting power margin of a power plant of the aircraft relative to a power limit at an operating rating of an engine of the power plant. The limiting power margin is transformed into a collective pitch margin for the operating rating. The collective pitch margin represents the margin between a current collective pitch of blades of a main rotor of the aircraft and a collective pitch limit of the blades of the main rotor. The collective pitch limit is determined and then displayed on a display of the aircraft for a pilot to view.