Fuselage-Mounted Landing Gear Load Path for Composite Wing Relief
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Solution Overview
Problem
Existing aircraft landing gear systems are not efficient in reducing the structural reinforcement of the aircraft's structural reinforcement of the aircraft's structural reinforcement, particularly for composite wings, leading to increased weight and manufacturing difficulties, and require complex multiple attachment points that are not compact when retracted.
Innovation Solution
Aircraft landing gear assembly with a drag stay and main fitting that transfers loads to the aircraft's fuselage via the aircraft's fuselage via a drag stay and main fitting that transfers loads via a drag system and main fitting that bypasses the aircraft's fuselage, allowing the aircraft to bypass the wing, with a retractable configuration that reduces the need for additional structural reinforcement and provides stability during taxiing, take-off, and landing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a landing gear is attached to the aircraft at multiple points including points on both the wing and the fuselage, then the loads experienced at any one point of attachment are reduced, but significant off-axis loads are still transferred to the wing and the structure becomes more complex
Solution Approach 1:
The invention extracts the load-bearing function from the wing by routing all landing gear loads through the fuselage. The drag stay and main fitting are configured to transfer loads directly to fuselage attachment points, completely removing the wing from the load path and eliminating off-axis bending moments in the wing structure.
Solution Approach 2:
The landing gear attachment system is segmented into distinct functional components: the drag stay for drag loads, the main fitting for vertical loads, and multiple fuselage attachment points distributed to handle different load components. This segmentation allows each component to be optimized for its specific load type while collectively transferring all loads to the fuselage.
2Strength
If additional structural reinforcement is provided in the aircraft to support landing gear loads, then the landing gear can be supported, but the weight of the aircraft increases
Solution Approach 1:
The invention extracts the landing gear load support function from the wing structure and relocates it to the fuselage. By routing all loads through the drag stay and main fitting to fuselage attachment points, the wing is completely removed from the load path, eliminating the need for additional wing reinforcement and its associated weight penalty.
3Force
If a multiple attachment point landing gear is used to reduce loads, then load distribution is improved, but the landing gear is not compact when retracted and requires more space within the wing
Solution Approach 1:
The invention extracts the landing gear from the wing volume by routing all attachment points to the fuselage. The drag stay and main fitting are configured to allow the landing gear to retract completely into the fuselage, removing it from the wing envelope entirely and eliminating the space conflict between landing gear and wing structure.
4Strength
If the landing gear transfers loads to the wing, then the landing gear can be supported, but the wing shape constraints are increased and manufacturing difficulties arise for composite wings
Solution Approach 1:
The invention extracts the landing gear load path from the wing structure entirely. By configuring the drag stay and main fitting to transfer all loads to fuselage attachment points, the wing is completely removed from the load-bearing function, eliminating all shape constraints and manufacturing complications associated with accommodating landing gear loads in composite wing structures.
Data Source
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AI summary
A retractable fuselage mounted landing gear assembly is disclosed. The landing gear assembly comprises a main strut, a drag stay and a landing gear main fitting. A first end of the drag stay is attached to the main strut and a second end of the drag stay is connected to the fuselage. A first end of the landing main fitting is attached to the main strut and a second end of the main fitting is connected to the fuselage. When the landing gear is extended, substantially all the landing gear loads are transferred from the landing gear to the fuselage via one or more of the drag stay and the main fitting.