How Do Aircraft Axles Support Landing Gear Systems?

Aircraft landing gear systems are among the most vital assemblies of any airframe, ensuring safe takeoff, landing, and taxi operations. While a typical landing gear assembly will consist of various aircraft parts that are necessary for standard functionality, axles in particular prove critical in their role of bearing substantial loads, facilitating smooth ground maneuverability, and supporting braking operations. While often overlooked compared to engines or avionics, axles are indispensable for the reliability and safety of modern aviation operations. In this blog, we will explore how aircraft axles function, discussing the engineering principles behind their design and their role in supporting landing gear systems.

An Introduction to Aircraft Axles

Aircraft axles are robust structural components that connect landing gear wheels to struts and other gear elements. With their implementation, the weight of an aircraft can be supported during ground operations while also transmitting the forces generated throughout takeoff and landing procedures.

Unlike automobile axles, which mainly facilitate wheel rotation and torque transmission, aircraft axles go beyond standard manufacturing expectations with their design ensuring optimal operations in the face of extreme vertical and lateral loads. Additionally, these axles are engineered to endure significant stress cycles while remaining lightweight in construction, ensuring they align with the aviation industry’s perpetual pursuit of efficiency and performance.

The Main Functions of Aircraft Axles

Aircraft axles are designed with multiple responsibilities in mind, with each of their primary functions contributing to overall safety and efficiency:

Load Bearing: When aircraft land, the vehicle’s kinetic energy transfers into the landing gear system. Axles distribute this load evenly across the wheels to prevent structural damage.
Wheel Support: Axles ensure that wheels remain properly aligned and functional during ground operations, enabling effective braking and steering.
Force Transmission: The forces produced by braking and directional changes on the ground travel through the axles to the landing gear struts and airframe, making the axle assembly necessary.
Durability Under Stress: Axles are engineered to resist fatigue that is caused by repetitive stress cycles, ensuring long service life under demanding conditions.

Important Design and Engineering Considerations

Aircraft axles must strike a balance between strength, weight, and durability, achieving this through several design and manufacturing techniques:

Material Selection: High-strength alloys like titanium or heat-treated steel are commonly used for the production of landing gear axles, these materials providing exceptional resistance to stress and corrosion without compromising weight goals.
Stress Distribution: Axles are shaped and machined to ensure even stress distribution under high loads, minimizing the risk of cracking or deformation.
Precision Machining: Axles require tight tolerances to interface correctly with wheels, bearings, and braking systems, where any deviations could lead to uneven wear or component failure.
Corrosion Resistance: Protective coatings and treatments are often applied to shield axles from moisture, deicing fluids, and other environmental hazards that may degrade health.

The Main Types of Axles Found on Aircraft

Fixed Axles: Fixed axles offer constant structural support for wheels, commonly being used in smaller aircraft where simplicity and reliability are prioritized over other objectives.
Stub Axles: Found in larger aircraft, stub axles are shorter than conventional options and are designed to carry wheels on only one side. They are also regularly paired with advanced braking systems to optimize performance.
Dual-Wheel Axles: Dual-wheel axles support multiple wheels, distributing heavy loads across a broader base. With this capability, they are standard in commercial airliners to manage the substantial weight of passengers, cargo, and fuel.

How to Maintain and Inspect Aircraft Axles

Due to the demanding conditions aircraft axles and landing gear assembly parts face, such components require operators to follow strict inspection and maintenance protocols. While exact practices will often vary, the most common tasks that one should carry out include the following:

Regular Visual Inspections: Checking for cracks, corrosion, or signs of wear that could compromise structural integrity is necessary before flights and during scheduled inspections.
Non-Destructive Testing (NDT): Ultrasonic and magnetic particle inspection techniques are useful for detecting hidden flaws when issues are suspected and typical checks do not find anything.
Lubrication and Bearing Checks: Axle performance is closely tied to the health of wheel bearings, which require proper lubrication and monitoring to prevent premature failure.
Replacement Intervals: Even with proper care, axles have finite lifespans and should be replaced in accordance with manufacturer recommendations or after detecting signs of fatigue.

The Importance of Securing Reliable Aircraft Axle Parts

Given their central role in landing gear systems, procuring high-quality axles for aircraft is non-negotiable for flight safety. For those seeking dependable aircraft axle components, AOG Purchasing is your sourcing solution with access to a plethora of quality-assured parts that are sourced from leading manufacturers and suppliers. We are also dedicated to hands-on service and streamlined fulfillment, providing hands-on service to ensure every need is thoroughly and expeditiously met. To see why so many customers steadily depend on AOG Purchasing, get in touch with our staff today!