SECTION II. THEORY OF OPERATION

TM 1-1520-238-T-4 3–14 3–6. CONTROLS AND INDICATORS (CONT) 3–6 Table 3–1. Landing Gear System Controls and Indicators M58-193 ADVISORY LIGHT UNLOCK/LOCK SWITCH Pilot TAIL WHEEL Panel SECTION II. THEORY OF OPERATION 3–7. SYSTEM DESCRIPTION 3–7 a. Landing Gear System. The purpose of the landing gear system is to support the helicopter for all ground operations and absorb landing shocks. The system consists of two MLGs and one TLG. (1) The MLG incorporates a trailing arm assembly which is connected at the top of the cross tube assembly and has a wheel and tire mounted to the bottom. The cross tube assembly provides the major support structure for the helicopter. A shock strut is mounted on the angled trailing arm assembly to provide normal/high–impact energy absorption and to provide kneel/erect capability for the helicopter for transportation. The MLG has a separate brake system for each wheel and is operated by the toe portion of the directional control pedals in the pilot and CPG crew stations. The parking brake can only be locked from the pilot station but can be released from the either crew station. (2) The TLG trailing arm assembly is connected to the tail boom and has a fork and axle assembly with the wheel and tire mounted at the bottom. The fork provides 360° swiveling capability of the tail wheel. The TLG fork can be locked at center position manually or hydraulically. The TLG wheel and tire assembly also centers itself as weight is removed from the wheel. b. Purpose. The landing gear system provides support and ground stability for the helicopter fuselage during taxiing, takeoff, landing, towing and parking. The system dampens and absorbs landing shocks before they are transmitted to the airframe structure. The TLG swivels, with a wheel centering mechanism, for steering the helicopter on the ground, or can be locked when desired. The MLG provides mounting for the helicopter wheel brake assembly. c. System Operation. (1) MLG Assembly. The MLG assembly (fig. 3–13) consists of the cross tube assembly, trailing arm assembly, shock strut assembly, and the wheel and tire assembly. (a) Cross Tube Assembly. The cross tube assembly is a major support structure and provides an interconnecting pivot for the left and right MLG trailing arms, while transmitting loads from the trailing arm to the fuselage.