Figure 3–3. Trailing Arm Assembly

TM 1-1520-238-T-4 3–4 3–2. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont) 3–2 SHOCK STRUT TRAILING ARM ASSEMBLY TIE DOWN LUG LEFT MLG ASSEMBLY WHEEL BRAKE ASSEMBLY (INBOARD VIEW) WHEEL BRAKE HELICOPTER STRUCTURE FLANGE TRAILING ARM JACK PAD / TOW LUG ADAPTER STATIC GROUND CABLE WHEEL AND TIRE ASSEMBLY STEP SHOCK STRUT MOUNT CROSS TUBE AS SEMBLY AXLE M58-093 SQUAT SWITCH TARGET ASSEMBLY Figure 3–3. Trailing Arm Assembly (2) Trailing Arm Assembly. The trailing arm assembly (2 each) (fig. 3–3) attaches to the cross tube assembly and consists of a trailing arm and a wheel brake assembly. The trailing arm assembly transmits vertical loads to the shock strut assembly and absorbs longitudinal and lateral loads during landing. A tie down lug is located at the top outboard end of the assembly. The trailing arm attachment fitting contains Teflon/fiberglass bushings. A threaded cap is installed at the top of the left hand trailing arm attachment fitting for the installation of the squat switch target assembly. A step is installed on each trailing arm, secured by hardware that attaches the shock strut to the trailing arm tie down lugs, which provides access to the crew stations and the upper fuselage. An axle and flange is provided at the lower end of the trailing arm for mounting of the brake assembly. A removable jack pad/tow lug adapter is installed inboard of the wheel and brake assembly on the lower end of each trailing arm. A static ground cable is attached to the base of the left MLG trailing arm at the jack pad/tow lug attachment. (3) Shock Strut Assembly. The shock strut assembly (fig. 3–4), one each for the left and right side, is an air–oil shock absorber that consists of a cylinder, and an upper and lower pistons. The shock strut assembly absorbs or dampens the vertical forces induced by landing and provides lowering (kneeling) and raising (erecting) capability for transporting the helicopter. It is also capable of a high–impact energy absorption landing. The upper shock strut fitting is attached to the fuselage pivot mount. The lower shock strut fitting is attached to the center mount of the trailing arm. The cylinder contains the upper and lower pistons. For servicing the upper cylinder a hydraulic fill port and bleed port are located on the external side of the cylinder. The upper piston has a nitrogen fill port for servicing. A spherical bearing is installed in the upper end of the strut that serves as an attachment point for the pivot mount. The lower piston has a drain plug for servicing. A spherical bearing is located at the lower end of the strut and serves as a pivot attachment point and a kneeling coupling for maintenance or shipping of the helicopter.