Climb-Optimized Takeoff System Pitch Attitude Control
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Solution Overview
Problem
Current takeoff systems are limited by fixed pitch angles and rotation speeds, leading to non-optimal takeoff distances due to excess energy conversion into kinetic energy instead of potential gravitational energy, particularly in short airfields, and fail to account for variable piloting techniques and transient aerodynamics, resulting in longer takeoff distances and potential tail strikes.
Innovation Solution
A Climb-Optimized Takeoff System that automatically adjusts the pitch attitude during takeoff to its instantaneous constraining limit, using a pitch guidance subsystem and control system to optimize pitch and minimize tail strike risks while maximizing energy conversion into height, utilizing a variable pitch schedule based on actual takeoff conditions and aircraft geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed pitch angle is used during takeoff, then the aircraft can meet certification requirements and avoid tail strikes, but the takeoff distance increases due to excess energy conversion into kinetic energy instead of potential gravitational energy
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed, static pitch schedule to a dynamic pitch schedule that continuously adapts during takeoff. The system monitors actual takeoff conditions (speed, height, acceleration) and adjusts the pitch angle in real-time to optimize the balance between safety constraints and energy efficiency, thereby reducing takeoff distance while maintaining compliance with certification requirements.
Solution Approach 2:
The patent implements parameter changes by modifying the pitch angle as a variable parameter rather than a fixed value. The pitch schedule is adjusted based on changing takeoff parameters such as speed, height, and acceleration, allowing the system to optimize energy conversion at different phases of takeoff while still respecting geometric constraints to prevent tail strikes.
2Ease of operation
If a fixed rotation speed V R is used, then the takeoff procedure is simplified and easy to follow, but the takeoff distance is non-optimal due to excess energy conversion into kinetic energy
Solution Approach 1:
The patent applies self-service by enabling the aircraft's flight control system to automatically adjust the pitch schedule based on monitored takeoff conditions. The system serves itself by using its own sensors and processors to detect actual performance and make real-time pitch adjustments, eliminating the need for complex manual pilot calculations while optimizing takeoff distance.
Solution Approach 2:
The patent implements feedback by continuously monitoring takeoff parameters (speed, height, acceleration) and using this information to adjust the pitch schedule in real-time. The feedback loop allows the system to compare actual performance with target performance and make corrective pitch adjustments, optimizing energy conversion while maintaining ease of operation through automation.
3Device complexity
If simplified parametric models based on flight test data are used for segment d2 calculation, then the calculation process is simplified, but the model does not account for variable piloting techniques and transient aerodynamics, resulting in longer takeoff distances
Solution Approach 1:
The patent applies mechanics substitution by replacing complex manual piloting techniques with an automated flight control system. The system substitutes human judgment and variable piloting styles with a standardized yet adaptive control algorithm that consistently optimizes pitch based on actual takeoff conditions, eliminating variability while maintaining simplicity through automation.
Solution Approach 2:
The patent implements preliminary action by pre-calculating optimized pitch schedules based on expected takeoff conditions, then adjusting these pre-planned schedules in real-time based on actual performance. This allows the system to have a prepared optimization strategy ready before takeoff while adapting to actual conditions during execution, balancing preparation with real-time optimization.
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
This system enhances takeoff performance by optimizing pitch attitude during air transition, reducing takeoff distance, and ensuring safe clearance, thereby improving climb gradients and reducing the risk of tail strikes, while maintaining compliance with certification requirements.
Implementation Method 1
When the airplane is moving fast enough so that the amount of lift generated by the wings permits safe takeoff
Implementation Method 2
the pilot releases the brakes and controls the engines to increase thrust. The airplane begins moving down the runway faster and faster
Implementation Method 3
mathematically integrating movement equations reflecting the engines thrust, airplane lift, drag and weight in given atmospheric conditions
Implementation Method 4
potential gravitational energy at the end of air transition
Data Source
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AI summary
The Climb-Optimized Takeoff System is an aircraft functionality aimed at improving the takeoff performance. The improvement is obtained by allowing the airplane to rotate to an optimized pitch attitude at and after VR, while ensuring that the minimum required takeoff climb gradients and the geometric limitations of the airplane are being respected. The optimum takeoff performance is obtained by granting that the airplane pitch attitude, instead of being limited by a single takeoff constraint (such as a given pitch to avoid tail strike) is being tracked to its instantaneous, most constraining limit during the air transition phase (d2).