TM 1-1520-238-T-5
Change 1
75
72.
LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont)
72
b. Utility Hydraulic System.
The utility hydraulic system (fig. 72) 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, pistontype 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 rightside 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.