MD Helicopters CSP-900RMM-2 Servicing And Maintenance Download

Page: 1721 / 2144

CSP

−

900RMM

−

MD Helicopters, Inc.

Rotorcraft Maintenance Manual

Page 15

Revision 35

67-00-00

5. Vertical Stabilization Control Subsystem

(VSCS)

(Ref. Figure 4)

The VSCS is a stability augmentation control
system which uses the horizontal endplates to
augment directional control and stabilization.
The VSCS consists of the following compo
nents:

Collective Control Position Transducer
-

provides collective stick assembly position

to the left and right VSCS control units.

Right Lateral Accelerometer -

provides

the rotorcraft the lateral G force signal to
the right VSCS control unit.

VSCS Yaw Rate Gyros -

provide a yaw

rate signal to the left and right VSCS
control units.

VSCS Control Units -

command left and

right VSCS linear actuator position.

VSCS Linear Actuators -

controls

movement of the horizontal endplates.

Horizontal Endplates -

augment and

stabilize rotorcraft movement around the
vertical axis.

VSCS Position Indicators -

indicate the

position of the horizontal endplate.

A. Collective Control Position Transducer

The collective control position transducer is
located at the base of the collective controls
closet control rod. The transducer is a dual
channel DC rotary-type position transducer
used to measure the collective stick assembly
position. Each channel uses

15 Vdc

for

excitation and outputs a signal of the collective
stick assembly position. The collective control
position transducers provide position inputs to
the left and right VSCS control unit.

B. Right Linear Lateral Accelerometer

The linear lateral accelerometer is located in
the right avionics bay. The accelerometer uses

15 Vdc

input power and outputs a signal of

the rotorcraft lateral G forces to the right
VSCS control unit. The lateral acceleration
signal is

3.75 Vdc/g

C. VSCS Yaw Rate Gyros

The yaw rate gyros are located in the left and
right avionics bay, one on each side. The gyros
output a yaw rate signal to the VSCS control
units that is

80 mV/degree/second

. They

have a maximum rate output of

60 degrees/

second

D. VSCS Control Units

The VSCS control units are located in the right
and left avionics bays. The control units are
independent from each other including power
inputs, sensor inputs, and actuator interfaces.

Each control unit internally monitors its power
supply and feedback sensors and provides a
failure annunciation on the IIDS of detected
faults.

The VSCS control units command the actua
tors over a range of

3 degrees

from actuator

center based on collective position. The VSCS
control units use lateral accelerometer (right
only) and/or yaw rate gyro inputs to control
the actuators for the remainder of actuator
travel. The VSCS control units control the
VSCS position indicators.

E. VSCS Linear Actuators

The linear actuators are located in the
horizontal stabilizer. Each linear actuator is
connected to a mounting bracket and to one of
the horizontal endplate spar tubes. The
actuators control the position of the horizontal
endplates based on inputs from the VSCS
control units.

The actuators have an internal servo loop that
uses power and position commands supplied
by the VSCS control unit. The internal servo
loop returns actuator position to the control
units.

F. Endplate Spar Tube Assemblies

The endplate spar tube assemblies are
installed into the journal bearings in the
horizontal stabilizer assembly. The spar tubes
provide for the attachment of the cranks for
the VSCS actuators and installation of the
horizontal endplates.

Each spar tube assembly consists of a spar
tube and spar tube sleeves. The tube is
machined from titanium alloy. The sleeves are
machined from corrosion resistant steel and

MD Helicopters CSP-900RMM-2, Servicing And Maintenance

Search results

Summary of Contents for CSP-900RMM-2

Reviews:

Related manuals for CSP-900RMM-2

Brands by name

Popular brands