TM 1-1520-238-T-7
11–24
11–2.
LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (cont)
11–2
f. DASE.
DASE consists of a pilot ASE panel, two excitation transformers (ACA) or a transformer filter box
assembly (ACB), the DASEC, four servocylinders, nine LVDTs, and eight SPADs.
(1) Pilot ASE Panel.
The pilot ASE panel (fig. 11–6), located in the left-hand side of the pilot console,
provides the DASE system with five magnetic switches (PITCH, YAW, ROLL, ATTD/HOVER HOLD, and TST
BUCS) for system control and testing.
(2) Excitation Transformers (ACA).
The excitation transformers (fig. 11–7), located in the aft avionics
matrix module in the aft avionics bay, step down 115 VAC to 26 VAC for DASE operation. The excitation
transformers are circular, 1.5 inches in diameter, with three electrical leads extending 12 inches out of the
transformer case. The electrical leads are colored brown, red, and orange. Input of 115 VAC is applied to the
brown and orange leads and an output of 26 VAC is supplied from the red and orange leads.
(3) Transformer Filter Box Assembly (ACB).
The transformer filter box assembly, located in the aft
avionics bay near the aft avionics matrix module, steps down and filters 115 VAC to 26 VAC for DASE and BUCS
operation.
(4) DASEC.
The DASEC, mounted in the aft avionics bay, is a solid state LRU and contains replaceable
integrated circuit boards. Five connectors are mounted on the front of the DASEC – four connectors are used for
helicopter operation and the fifth connector is used for testing.
(5) Servocylinders.
Three servocylinders (fig. 11–8), located forward of the main transmission, are used
for longitudinal (pitch), collective (vertical), and lateral (roll) control of the helicopter. A fourth servocylinder is
mounted on the tail rotor gearbox for directional (yaw) control of the helicopter. The servocylinders control the
pitch of the main and tail rotor blades either mechanically or electrically. Electrically, the servocylinders are
controlled by DASE or BUCS inputs.
(6) LVDTs.
The longitudinal (pitch) and lateral (roll) LVDTs (fig. 11–9) are attached to the pilot and CPG
cyclic sticks. The collective (vertical) LVDTs are attached to the pilot and CPG collective sticks. The directional
(yaw) LVDTs are attached to the pilot and CPG directional pedals. The pilot has an additional LVDT attached to
the collective stick for main rotor engine speed droop. The LVDT sends an electrical signal to the DASEC that is
proportional to flight control movement.
(7) SPADs.
One SPAD (fig. 11–10) is located under the floor of each crew station. The longitudinal
(pitch) and lateral (roll) SPADs are attached to cyclic stick mechanical control linkages. The collective (vertical)
SPADs are attached to the pilot and CPG collective stick mechanical control linkages. The directional (yaw)
SPADs are attached to the pilot and CPG directional pedal mechanical control linkages. SPADs are used to
disconnect the mechanical flight control linkage and activate BUCS when a respective flight control linkage
becomes jammed and the shear pin is severed. Each SPAD consists of a shear pin, a retainer, a switch assembly,
a cam assembly and a spring assembly. The retainer is used to hold the shear pin in place. The switch assembly
consists of two switches which test and activate BUCS. The cam engages the switch assembly. The spring
assembly holds the cam assembly in the engaged position.
