Landing Gear (definition And Types)

c

Landing gear is a structure which installed on the aircraft for the purpose to support the weight of the aircraft whiles it on the ground and also allows the aircraft to land safely. Landing gear also provides mobility to the aircraft on ground or water. Aircrafts require landing gear for taxiing, takeoff, and landing. Initially aircrafts used skids as its landing gear. Times after times, wheels were attached to the skids. Since that time, various arrangements have been used for wheels and structures to connect them to the airplane. 



 
 















 









Tricycle gear is the most popular landing gear arrangements. The tricycle undercarriage includes two main gears just aft of the center of gravity and a smaller auxiliary gear near the nose. The main advantage of this layout is that it eliminates the ground loop problem of the ³taildragger´. This arrangement is instead a stable design because of the location of the main gear with respect to the center of gravity. As a result, a pilot has more latitude to land safely even when he is not aligned with the runway. !"#$

Quadricycle gear are also very similar to the tricycle arrangement except there are four main gear roughly equal in size and mounted along the fuselage. Like tricycle gear, the quadricycle undercarriage also requires a very flat attitude during takeoff and landing. This arrangement is also very sensitive to roll, crosswinds, and proper alignment with the runway. The most significant advantage of quadricycle gear is that the plane's floor can be very close to the ground for easier loading and unloading of cargo. However, this benefit comes at the price of much higher weight and drag than bicycle gear. %&' &%&#

Conventional landing gear consists of two wheels forward of the aircraft's center of gravity and a third small wheel at the tail. This type of landing gear is most often seen in older general aviation airplanes. The two main wheels are fastened to the fuselage by struts. Without a wheel at the nose of the plane, it easily pitches over if brakes are applied too soon. Because the tailwheel is castered (free to move in any direction) the plane is ve ry difficult to control when landing or taking off. "&%&' &%&#

Aircraft that have to land on water are fitted with skids rather than wheels. These skids are the unconventional landing gears for the aircraft. Some planes had interchangeable skids and wheels so that the plane could be used to land both on land and on water. Other than skids, skis and floats also the unconventional gears. #&$ (

The tandem landing gear is used for very large aircraft like the B-52 bomber and the U-2 reconnaissance/research aircraft. The main landing gear is in two sets that are located one behind the other on the fuselage. The tandem landing gear allows the use of a highly flexible wing, but it may also require the use of small wheels on the tips of the wings to keep the wings from scraping the ground. )%* 



Another type of landing gear is the use of multiple wheels per landing gear strut. It is especially common to place two wheels on the nose strut of the tricycle arrangement to provide safety and steering control in case of a tire blowout. This additional tire is particularly useful on carrier -based aircraft where two nose wheels are a requirement. When multiple wheels are placed on the same gear unit, they are attached together on a structural device called a bogey. The heavier the aircraft becomes, the more wheels are typically added to the bogey to spread the plane's weight more evenly across the runway pavement.