Why Most Helicopters Use Landing Skids Instead of Wheels

Helicopters are prized for their ability to vertically take off, hover, and land on uneven or confined surfaces. However, this flexibility brings a distinct set of design challenges, especially when it comes to landing gear. Where most aircraft rely on tricycle or taildragger wheel configurations, the majority of helicopters utilize landing skids to maintain their agility. In this blog, we will cover everything you need to know about the basic structure of helicopter landing skids and why they are favored over wheeled alternatives, as well as discuss some exceptions to this rule.

The Design of Helicopter Landing Skids 

Landing skids are fixed directly to the underside of a helicopter’s fuselage, these rigid structures typically being fabricated from high-strength aluminum alloys, titanium, or advanced composite materials to absorb both impacts and the aircraft’s weight without adding too much mass. A standard skid configuration consists of:

• Two longitudinal skid tubes that run parallel beneath the helicopter, made to touch the ground
• Transverse cross tubes that connect the skids and securely attach them to the airframe
• Shock-absorbing attachment points or dampeners that help distribute landing forces and minimize structural stress

Moreover, the forward and rear ends of most skid tubes are usually curved upward to prevent them from digging into uneven terrain or catching on obstructions.

Variations in Design 

The basic form of landing gear stays largely the same across helicopter models, but some are modified to serve different missions, terrains, and aircraft sizes, such as:

• Energy-absorbing skids: Common on military, training, or utility helicopters, these skids feature integrated crushable elements or hydraulic dampers within the cross tubes or mounting points that dissipate impact energy during hard landings.
• High-clearance skids: Built with extended vertical supports, these skids lift the fuselage higher above the ground to prevent contact with large rocks, thick vegetation, or uneven surfaces.
• Retractable skids: Mostly reserved for advanced, high-speed platforms where performance optimization justifies the added mechanical complexity, some helicopters use retractable skid systems that can be raised during flight to reduce drag.
• Snow or float attachments: For operations in snowy, swampy, or flooded environments, standard skid tubes can be fitted with accessories like snow pads, flotation gear, or bear paws to increase surface area and prevent them from sinking.

Helicopter Models That Use Wheeled Landing Gear

While the majority of helicopters rely on landing skids, some employ wheeled landing gear for specific functional advantages, including the:

• Sikorsky UH-60 Black Hawk: This utility helicopter features retractable tricycle wheel gear to support heavier payloads and allow it to taxi on prepared surfaces, serving military and medical evacuation missions.
• CH-47 Chinook: Built for heavy-lift transport of troops and cargo, the Chinook employs a fixed quad-wheel gear system mounted on tandem fuselage sections.
• AgustaWestland AW101: A medium-lift, multi-role military helicopter equipped with fully retractable tricycle landing gear, the AW101 is optimized for operations from runways and aircraft carriers.

Models like the above are often larger, heavier, and operate where runway-based ground movement is expected. However, wheels do not perform well on soft or rugged terrain, and helicopters that incorporate them may also require tugs or tow vehicles for ground maneuvering. Despite these drawbacks, wheeled landing gear can be beneficial for helicopters that have to unload cargo or be easily mobile on the ground.

The Advantages of Landing Skids over Wheels

1. Weight Efficiency 

Skids are lighter than wheeled landing gear systems, contributing to better fuel economy and increased payload capacity. This is especially true for smaller helicopter designs, where every bit of weight saved matters.

2. Simplicity and Reliability 

Unlike wheeled gear systems that much of the time contain brakes, steering components, and retractable mechanisms, skids have no moving parts, therefore reducing mechanical failure points.

3. Vertical Operation Compatibility 

Landing skids are well-suited to vertical takeoff and landing, offering a wide and stable base that eliminates the need for ground roll or directional steering during touchdown and liftoff.

4. Superior Ground Stability 

The larger surface contact area of skids also distributes weight more evenly across the ground, improving stability on soft or uneven terrain.

Uphold Helicopter Skid Functionality with Quality Parts 

Landing skids are the most practical solution for the vast majority of helicopter applications, and though they are simple in design, maintaining them with high-quality components as needed is crucial. If you are seeking trusted procurement solutions for landing skids, dampers, tubes, and other such parts, turn to Expansive Aviation.

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