The chassis of the aircraft: from the Flyer of the Wright brothers to Ruslan

Since the first airplanes have risen in the air, continuous improvement of aviation technology continues. An integral part of each aircraft is a device used for its movement on the ground (or water) for the purpose of dispersal before take-off or braking after landing.

It is a fascinating sight to watch the seemingly bulky mechanical system of an airplane (chassis) consisting of a multitude of elements, after being detached from the runway, it easily folds up, taking on a compact outline, and hides under the flaps in its fuselage or wings.

The classic "land" chassis of the aircraft consists of two main elements - pillars and wheels, also called pneumatics. In those cases where it is required to create an opportunity for operation on snow cover or water, some aircraft models provide for the installation of replaceable elements in contact with the landing surface, such as skis or floats.

Until the mid-thirties of the XX century, the world aircraft industry was dominated by the unassembled construction of the airplane chassis. It was undoubtedly more reliable, but it created great aerodynamic resistance, which required various engineering tricks, such as additional fairings and refinement of the profile of the main racks. Over time, this scheme was largely abandoned, although some types of aircraft of the so-called "small" aviation use it to this day. An example is the "celestial long-liver" An-2, the design of which has not been changed since 1949.

The development of fighter aircraft required an increase in speed. Racks, previously equipped with only shock absorbers, have become more complicated, and the mechanism for picking wheels in the plane or the fuselage has placed complex technical problems for the engineers, but the result was worth it. The chassis of the IL-16 aircraft became a revolutionary solution, they were cleaned for the first time on a mass-produced fighter that gave our volunteer pilots the opportunity to win victories in the skies of the warring Spain.

By its variety, a little element of the design can be compared with the chassis of the aircraft. The scheme, which has received the greatest distribution in modern aircraft building, is three-bearing. It involves two main racks and one auxiliary (most often - the nose, assuming up to 9% of the weight of the aircraft). However, half a century ago, the additional support was most often installed on the tail.

Some aircraft designs had, in addition to the main three pillars, also insuring. She assumed the burden in case of unsuccessful landing (for example IL-62). With the increase in the takeoff weight of the two main supports was not enough. The number of pneumatics in the AN-124 Ruslan reached 24. The Boeing-747 airplane was designed in accordance with a multi-shelf design.

Landing is the most crucial moment in the whole flight, every pilot knows it. Therefore, both the reliability of the design and the materials for manufacturing chassis racks, the requirements are very high. Durable precision alloys, from which they are performed, provide the ability to withstand loads with multiple reserves. And in order to ensure that the number of take-offs always coincides with the number of landings, backup and emergency release systems of racks are also created. Just in case.