Landing Gear Arrangements

As landing gear systems are among the most important components of an aircraft to ensure safe flight, they appear on all types of fixed-wing aircraft. Generally speaking, fixed-wing aircraft landing gear systems come in three arrangements: tailwheel type, tandem type, and tricycle type. This blog will explain each of the three types and their unique characteristics.

The first type of landing gear is known as tailwheel type landing gear. This was used by virtually all early aircraft models, and is thus commonly known as conventional landing gear. In this setup, the main landing gear is located ahead of the center of gravity, requiring the tail to need additional support from a third wheel assembly. This third wheel helps slow the aircraft upon touchdown and provides greater directional stability. This setup also results in an angling of the fuselage, allowing the aircraft to use a long propeller that compensates for older, less powerful engines. The increased clearance of the forward fuselage provides additional advantage when operating in and out of unpaved runways.

Today, many aircraft are manufactured with conventional gear for these reasons, as well as the weight-saving benefits that come with the comparatively light tailwheel assembly. Early aircraft featured a skid in place of the tail wheel, but the proliferation of hard surface runways have caused the skid to become effectively obsolete. In tailwheel assemblies, directional control is achieved through differential braking until the speed of the aircraft drops to such a speed where the rudder can control it.

The second type of landing gear, tandem landing gear, is very uncommon. As its name suggests, tandem landing gear features the main and tail gears aligned with one another along the longitudinal axis of the aircraft. This setup is common in sailplanes, though many sailplanes have just one actual landing gear on the fuselage and a skid below the tail. Some military bombers, such as the Boeing B-47 and B-52 bombers, use tandem gear. Additionally, the U2 spy plane and VTOL Harrier use tandem gear, though the Harrier also features small outrigger gear under the wings for added support. An advantage of tandem gear is that it allows for the use of very flexible wings, because all landing gear is located below the fuselage.

The final type of landing gear, tricycle type, is the most commonly used landing gear arrangement. It comprises a combination of main landing gear and nose landing gear. Most (but not all) tricycle type landing gear systems feature a steerable nose that is connected through mechanical linkage to the rubber pedals. Heavy aircraft, like commercial airliners, use hydraulic power to control the nose gear. The number and location of the wheels of main gear varies, but most have at least two wheels.

Tricycle landing gear offers significant advantages over other types. First, it allows a more forceful application of brakes without nosing over, enabling aircraft to land at much higher speeds. Secondly, this landing gear provides much better visibility from the flight deck, particularly when landing and maneuvering on the ground. Lastly, tricycle landing gear prevents ground-looping of the aircraft, wherein aerodynamic forces cause a wing to rise, forcing the other wing into the ground. Because the center of gravity is ahead of the main gear, action on the center of gravity tends to move the aircraft forward, rather than side-to-side as in tailwheel landing gear.

Regardless of type, all aircraft need landing gear. As landing gear is such a critical piece of equipment, be sure to get your parts from a trusted source like ASAP Supply Chain.

At ASAP Supply Chain, owned and operated by ASAP Semiconductor, we can help you source all types of aircraft landing gear parts and deliver them with some of the industry’s best lead times. Additionally, as we are the only independent distributor with a strict No China Sourcing Policy, we can ensure that each part you buy from us will come from a trusted manufacturer. We’re always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, call us at 1-702-919-1616 or email us at sales@asap-supplychain.com. Our team of dedicated account managers is standing by and will respond to you in 15 minutes or less.