Rotary Wing Supplemental Wing Pitch Control
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Solution Overview
Problem
Existing rotary wing aircraft lose main rotor control authority at high speeds when transitioning to wing-provided lift, requiring substantial modifications to control systems and pilot training to integrate supplemental wings, which is not feasible with current technologies.
Innovation Solution
A supplemental wing system that rotates between hover and forward flight positions, maintaining main rotor control authority through adjustable pitch and trim control surfaces, and can be retrofitted to existing helicopters without additional training, using a modular design with power assist systems to overcome friction and aerodynamic forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a supplemental wing is added to a prior art helicopter to create a compound aircraft, then lift efficiency and operational versatility are improved, but control system complexity increases and pilot training requirements increase
Solution Approach 1:
The supplemental wing is designed to automatically adjust its pitch angle in response to aerodynamic forces and aircraft motion, eliminating the need for complex control systems to manage wing positioning. The wing self-regulates to maintain optimal performance across different flight regimes, resolving the contradiction by achieving versatility without proportionally increasing control complexity
Solution Approach 2:
The supplemental wing structure serves multiple functions: providing lift during forward flight, reducing vibration during hover, and enabling efficient operation across various speeds. This multi-functionality achieves enhanced operational versatility without requiring separate control mechanisms for each function, thereby limiting the increase in control system complexity
2Productivity
If a supplemental wing is added to a prior art helicopter, then lift efficiency is improved, but pilot training requirements increase
Solution Approach 1:
The supplemental wing automatically adjusts its pitch to maintain main rotor control authority at high forward speeds and to avoid translation in the aft direction when in hover position, eliminating the need for pilot intervention or retraining. The wing self-regulates based on aerodynamic forces, allowing conventional helicopter pilots to operate the compound aircraft without additional training while maintaining improved lift efficiency
Solution Approach 2:
The supplemental wing incorporates automatic pitch adjustment through feedback from aerodynamic forces acting on the wing structure. The pitch angle automatically responds to flight conditions, providing stable and predictable performance that does not require pilot adaptation or retraining, thus maintaining ease of operation while improving lift efficiency
3Productivity
If the supplemental wing provides all or substantially all of the lift at high speeds, then wing efficiency is improved, but main rotor control authority is lost
Solution Approach 1:
The supplemental wing's pitch angle is dynamically adjusted based on aircraft speed and flight conditions. At high forward speeds, the wing assumes a pitch angle that provides optimal lift efficiency. At lower speeds or during hover, the pitch angle automatically changes to ensure the main rotor retains sufficient control authority. This dynamic adjustment resolves the contradiction by allowing the wing to be highly efficient at cruise while maintaining rotor control authority when needed
Solution Approach 2:
The supplemental wing changes its pitch parameter automatically in response to flight conditions. The pitch angle is adjusted so that the wing provides the appropriate proportion of lift at different speeds, ensuring that main rotor control authority is maintained at high forward speeds while wing efficiency is optimized. This parameter change resolves the contradiction between wing efficiency and rotor control authority
4Adaptability or versatility
If the supplemental wing is designed to rotate between hover and forward flight positions, then operational flexibility is improved, but friction resistance increases
Solution Approach 1:
The supplemental wing incorporates a power assist system that uses pneumatic or hydraulic forces to overcome friction resistance during rotation between hover and forward flight positions. This assistance enables smooth transitions and maintains operational flexibility while reducing the friction force that would otherwise impede the wing's movement, resolving the contradiction between flexibility and friction resistance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient operation with reduced vibration and maintenance costs, allowing conventional helicopter pilots to fly modified aircraft with minimal training, while maintaining main rotor control authority and enhancing operational flexibility and efficiency.
Implementation Method 1
The wing portions generate lift in response to the relative wind
Implementation Method 2
The wing portions and wing spar are free to rotate between the hover and forward flight positions in response to external moments, such as relative wind blowing against or over the wing
Data Source
AI summary
A supplemental wing for a rotary wing aircraft rotates about a pitch axis between a forward flight position and a hover position. The supplemental wing generates lift and generates both positive and negative pitching moments that balance and that may passively rotate the supplemental wing to an equilibrium position. The supplemental wing may use power assist to overcome friction to move to the equilibrium position. The lift generated by the supplemental wing reduces at high forward speeds to preserve main rotor control authority. The supplemental wing rotates to avoid aft translation when in the hover position. The supplemental wing may be retrofitted to existing helicopters and flown using existing helicopter controls without pilot re-training.