Retractable Sled Landing Gear for Hard Pavement and Soft Snow

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Solution Overview

Problem

Aircrafts with conventional wheeled landing gear are incapable of operating on soft snow surfaces due to excessive contact pressure, causing sinking and potential accidents.

Innovation Solution

A sled landing gear system with retractable steel cables and a hydraulic actuator is installed, allowing the aircraft to extend or retract the sled for operation on both hard pavements and soft snow surfaces, maintaining balance and stability through a complex mechanism involving torque tubes, rocker arms, and rotating baffles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional wheeled landing gear is used, then the aircraft can operate on hard pavements, but it cannot operate on soft snow surfaces due to excessive contact pressure

Engineering Contradiction:
Improveoperating capability on different surfacesVSAvoidcontact pressure on soft snow
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The landing gear system dynamically changes its configuration by retracting or extending the sled boards based on the operating surface conditions. The sled boards are normally retracted for conventional pavement operation but can be extended when snow detection is triggered, allowing the contact area to adapt dynamically to the surface conditions and reduce contact pressure on soft snow.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The landing gear is designed with multi-functionality to operate on both conventional hard pavements and soft snow surfaces. The sled boards serve as additional contact surfaces that can be deployed when needed, making the same landing gear system universally applicable to different operating environments without requiring separate specialized gear for each surface type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If sled boards are extended to increase contact area, then contact pressure on snow is reduced, but the device complexity increases

Engineering Contradiction:
Improvecontact pressure on soft snowVSAvoidstructure complexity of landing gear
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The sled boards are designed to nest within or alongside the conventional landing gear structure when retracted, minimizing the space required and reducing visual complexity. The steel cables and actuation mechanisms are integrated into the existing gear architecture, allowing the snow adaptation feature to be contained within the footprint of the conventional landing gear system.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4631853A1Sled landing gear and method for using same
Publication Date: 2025.10.15 HARBIN
  • EP4631853A1 patent drawingFigure 1~2
  • EP4631853A1 patent drawingFigure 3
  • EP4631853A1 patent drawingFigure 4

AI summary

A sled landing gear and a method for using same. The sled landing gear comprises a main landing gear (100), a front steel cable (200), a rear steel cable (300), a retractable steel cable (400), a main gear sled (500), and a retraction/extension device. The main gear sled (500) is a double-board structure with an opening. An end of the front steel cable (200) is connected to the main landing gear (100). Another end of the front steel cable (200) is connected to a front end of the main gear sled (500). An end of the rear steel cable (300) is connected to the main landing gear (100). Another end of the rear steel cable (300) is connected to a rear end of the main gear sled (500). An end of the retractable steel cable (400) is connected to a middle section of the rear steel cable (300). Another end of the retractable steel cable (400) is connected to the retraction/extension device. The retraction/extension device controls retraction and extension of the sled via the retractable steel cable.