Aircraft Hard-Landing Detection via Shock Strut Stroke Profile
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Solution Overview
Problem
Conventional methods for detecting hard landings in aircraft are subjective and unreliable, leading to potential structural damage going unnoticed or resulting in unnecessary inspections and resource expenditure.
Innovation Solution
A hard-landing detection system integrated with shock struts in aircraft landing gear, utilizing sensors and a controller to measure and analyze parameters such as stroke profile, gas pressure, oil pressure, and vertical load to objectively determine if a landing event is hard, triggering inspections only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pilot subjective declaration is used to detect hard landings, then detection simplicity is maintained, but detection reliability deteriorates
Solution Approach 1:
The patent replaces the mechanical/subjective detection method (pilot declaration) with an automated sensor-based system. Sensors mounted on the aircraft structure detect acceleration forces during landing, and a processor objectively determines whether the landing force exceeds predetermined thresholds, eliminating subjective judgment while maintaining operational simplicity through automatic detection.
2Reliability
If automated sensor-based detection is implemented, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The detection system is segmented into distinct functional modules: sensors mounted on specific aircraft structures to detect acceleration, a processor that analyzes sensor data against predetermined thresholds, and a notification system. This modular segmentation allows each component to perform its specific function reliably while keeping the overall system manageable and maintainable.
3Loss of substance
If subjective hard-landing detection is used, then inspection resources are conserved, but structural damage may go unnoticed
Solution Approach 1:
The system provides immediate feedback by automatically comparing detected landing forces against predetermined thresholds and generating notifications when hard landings are detected. This feedback mechanism ensures that potential structural damage is reliably identified and reported, enabling timely inspections while avoiding unnecessary inspections for normal landings, thus optimizing resource allocation.
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
The system provides a reliable and objective means to detect hard landings, reducing unnecessary inspections and ensuring timely identification of structural damage, thereby enhancing aircraft safety and operational efficiency.
Implementation Method 1
The gas acts as an energy storage device, such as a spring, so that upon termination of a compressing force the shock strut returns to its original length
Implementation Method 2
Shock struts also dissipate energy by passing the oil through the orifice so that as the shock absorber is compressed or extended, its rate of motion is limited by the damping action from the interaction of the orifice and the oil
Data Source
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AI summary
A hard-landing detection system includes a wheel assembly (106), a shock strut (104) mechanically coupled to the wheel assembly and to landing gear structure of the landing gear assembly, a controller (230) having a processor, and a tangible, non-transitory memory configured to communicate with the processor. The tangible, non-transitory memory has instructions stored thereon that, in response to execution by the processor, cause the hard-landing detection system to perform operations that include detecting, by the processor, a landing event and determining, by the processor, whether the landing event is hard. The hard-landing system may further include a stroke position sensor (116) and detecting the landing event may include using the stroke position sensor to measure a stroke profile of the shock strut. Further, determining whether the landing event is hard may include comparing, by the processor, the stroke profile of the shock strut to a predetermined maximum shock strut stroke.