b. Utility Hydraulic System

TM 1-1520-238-T-5 Change 1 7–5 7–2. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont) 7–2 b. Utility Hydraulic System. The utility hydraulic system (fig. 7–2) consists of the utility hydraulic pump, utility hydraulic manifold, utility GSE panel, longitudinal servocylinder, lateral servocylinder, collective servocylinder, and the directional servocylinder, utility hydraulic accumulator assembly, tail wheel lock control valve, low level shutoff valve, and the utility hydraulic return accumulator. (1) Utility Hydraulic Pump. The utility hydraulic pump, located on the right forward drive pad of the main transmission accessory gear train housing, pressurizes and transfers fluid for system operation. The utility hydraulic pump is a constant pressure, variable delivery, piston–type pump driven by the main transmission accessory geartrain. The external drive shaft mates with the transmission accessory geartrain and is designed to shear under excessive loads. (2) Utility Hydraulic Manifold. The utility hydraulic manifold, located on the right–side of the aft equipment bay deck, stores, filters and routes hydraulic fluid for system operation. (3) Deleted. (4) Utility GSE Panel. The utility GSE panel, located on the aft equipment bay deck outboard of the utility manifold, provides connections for external hydraulic application used for servicing primary and utility reservoirs, and charging/bleeding the gas reservoir and accumulator with nitrogen. (5) Longitudinal Servocylinder. The longitudinal servocylinder, located on the left transmission deck in front and to the right of the main transmission, converts mechanical inputs during normal operation, or electrical inputs during DASE BUCS operation, into hydraulic pressure outputs which are sent to the main rotor swashplate. (6) Lateral Servocylinder. The lateral servocylinder, located on the transmission deck in front and to the left of the main transmission, converts mechanical inputs during normal operation, or electrical inputs during DASE BUCS operation, into hydraulic pressure outputs which are sent to the main rotor swashplate. (7) Collective Servocylinder. The collective servocylinder, located on the transmission deck in front of the main transmission, converts mechanical inputs during normal operation, or electrical inputs during DASE BUCS operation, into hydraulic pressure outputs which are sent to the main rotor swashplate. (8) Directional Servocylinder. The directional servocylinder, located on the top of the tail rotor gearbox, converts mechanical inputs during normal operation, or electrical inputs during DASE BUCS operation, into hydraulic pressure outputs which are sent to the tail rotor swashplate. (9) Utility Hydraulic Accumulator Assembly. The utility hydraulic accumulator assembly, located on the right side of the aft equipment bay underneath the APU, stores and restricts the rate of hydraulic fluid flow under high pressure for APU starting, rotor brake operation and emergency operation of flight control servocylinders. (10) Tail Wheel Lock Control Valve. The tail wheel lock control valve, located at the end of the tail boom slightly forward of the intermediate gearbox, controls hydraulic pressure to the tail wheel lock actuator. (11) Low Level Shutoff Valve. The low level shutoff valve, located in the forward top portion of the tail boom just aft of the GSE panels, shuts off utility hydraulic fluid flow to the directional servocylinder and tail wheel lock control valve.