TM 1-1520-238-T-7
11–2
SECTION I.
EQUIPMENT DESCRIPTION AND DATA
11–1.
EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES
11–1
a. Characteristics.
(1) Force Trim.
The force trim system permits selection of flight control references to allow for limited
hands-off flying.
(2) Collective Flight Control System.
The collective control system provides mechanical control input
to the main rotor system for vertical flight control of the helicopter.
(3) Longitudinal (Cyclic) Flight Control System.
The longitudinal (cyclic) flight control system provides
mechanical inputs to the main rotor system for longitudinal flight control of the helicopter.
(4) Lateral (Cyclic) Flight Control System.
The lateral (cyclic) flight control system provides
mechanical inputs to the main rotor system for left and right flight control of the helicopter.
(5) Directional Flight Control System.
The directional flight control system provides mechanical input
to the tail rotor assembly for directional heading and anti-torque control.
(6) Digital Automatic Stabilization Equipment (DASE).
The DASE system receives and transmits
flight reference signals for control and stability of the helicopter.
(7) Stabilator Control System (SCS).
The SCS provides a means to automatically or manually position
the stabilator to enhance helicopter handling characteristics and improve over the nose visibility for landing or
nap-of-earth (NOE) operations.
b. Capabilities and Features.
(1) Force Trim.
The force trim system holds the cyclic sticks and the directional pedals in a neutral
(reference) position selected by the pilot.
(2) Collective Flight Control System.
The collective flight control system provides the pilot and CPG
with mechanical flight controls. The primary hydraulic system pressure boosts the operation of the collective stick
by the use of servocylinders operating at 3000 psi. The utility hydraulic system provides redundant hydraulic
power to the servocylinders and utility hydraulic subsystems. Flight can be maintained by use of the fly-by-wire
backup control system (BUCS) if mechanical flight control is lost. All mechanical control flight linkages are routed
separately from BUCS to preclude the loss of both systems.
(3) Longitudinal (Cyclic) Flight Control System.
The longitudinal flight control system provides the
same capabilities and features as the collective flight control system.
(4) Lateral (Cyclic) Flight Control System.
The lateral flight control system provides the same
capabilities and features as the collective and longitudinal flight control systems.
(5) Directional Flight Control System.
The directional flight control system provides control for the tail
rotor assembly to counteract the torque of the main rotor assembly. The system is power assisted by a hydraulic
servocylinder. Control of the directional flight control system can be maintained from either crew station or by
BUCS. Adjustable (fore and aft) directional pedals are installed in the pilot and CPG stations. The directional
mechanical control linkage is routed through the lower part of the fuselage (left of the centerline) to the aft
equipment bay, then along the top of the aft fuselage and tail boom to the servocylinder which is mounted on the
tail rotor gearbox. All mechanical flight control linkages are routed separately from BUCS to preclude the loss of
both systems.
