Main Landing Gear

Figure 1-11.—Main landing gear. conventional type. The tricycle gear is more stable during ground operations and makes landing easier, especially in crosswinds. It also maintains the fuselage in a level position that increases the pilot’s visibility. Nearly all Navy aircraft are equipped with tricycle landing gear. Main Landing Gear A main landing gear assembly is shown in figure 1-11. The major components of the assembly are the shock strut, tire, tube, wheel, brake assembly, retracting and extending mechanism, and side struts and supports. Tires, tubes, and wheels are discussed in chapter 11 of this TRAMAN. The shock strut absorbs the shock that otherwise would be sustained by the airframe structure during takeoff, taxiing, and landing. The air-oil shock strut is used on all Navy aircraft. This type of strut is composed essentially of two telescoping cylinders filled with hydraulic fluid and compressed air or nitrogen. Figure 1-12 shows the internal construction of a shock strut. The telescoping cylinders, known as cylinder and piston, form an upper and lower chamber for the movement of the fluid. The lower chamber (piston) is always filled with fluid, while the upper chamber (cylinder) contains the compressed air or nitrogen. An orifice is placed between the two chambers through which the fluid passes into the upper chamber during compression and returns during extension of the strut. The size of the orifice is controlled by the up-and-down movement of the tapered metering pin. Whenever a load is placed on the strut because of the landing or taxiing of the aircraft, compression of the two strut halves starts. The piston (to which wheel and axle are attached) forces fluid through the orifice into the cylinder and compresses the air or nitrogen above it. 1-12