The landing gear of the aircraft, commonly known as the "leg of the aircraft", is the core system used for take-off, landing, taxiing and ground stop-off on the aircraft. It is far more than just a few wheels, but a precision engineering component that integrates structural mechanics, hydraulic system, shock absorption technology and material science.
I. Core functions
1. Support function: support the entire weight of the aircraft when parking, taxiing, taking off and landing on the ground.
2. Shock absorption function: absorb and dissipate the huge impact energy generated by the aircraft when landing and gliding unevenly on the ground, ensuring the structure of the aircraft and the comfort of passengers. This is achieved through shock-absorbing pillars (usually filled with nitrogen and oil inside).
3. Gliding and maneuvering function: provide the ability to roll for the aircraft to move on the ground. The front landing gear usually also has a steering function, allowing the pilot to control the plane to turn on the taxiway.
4. Braking function: The main landing gear is equipped with a powerful braking system (similar to car brakes, but with great power), which is used to slow down after landing and control the speed when taxiing. The pushback device and spoiler also need to work with the landing gear (grounding signal trigger).
II. Main structural composition
A typical landing gear set contains the following key parts:
1. Shock-absorbing pillar: The core shock-absorbing component, like a huge pump, absorbs shock energy by compressing the internal gas and forcing the oil through small holes.
2. Wheels: including hubs, tires (usually nitrogen-filled tubeless tires) and brake pads. The tire pressure of airplane tires is very high, which is several times that of car tires.
3. Brake system: The multi-disk brake system will generate extremely high temperature when braking at high speed, so the brake pads are often made of carbon composite materials, which are resistant to high temperature and lightweight.
4. Release system: a complex hydraulic or electric mechanical system used to put the landing gear into the cabin after take-off to reduce flight drag; and put it down and lock it before landing.
5. Torsion arm: an important connecting rod that connects the shock-absorbing pillar and the body to prevent the pillar from twisting when subjected to landing impact.
6. Support rod and moving cylinder: the connecting rod and hydraulic moving cylinder used to support and retract the landing gear.
2025/9/1