MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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97-06-00
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Revision 12
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright
©
1999 − 2016 by MD Helicopters, Inc.
INTEGRATED INTERPHONE COMMUNICATION SYSTEM
(CARTER)
MAINTENANCE PRACTICES
1. CE 500 HT − 3G ICS Control Unit
Replacement
(Ref. Figure 201 and Figure 202)
(1). Ensure that all power is OFF.
(2). (LH command helicopters only) Remove
right side fairing from instrument
panel.
(3). Unplug connector P509 from ICS
control unit.
(4). Remove four screws and washers
securing unit to instrument panel.
NOTE:
If unit is to be reinstalled, do not dis­
turb the settings of external and COMM 1
and COMM 2 sidetone level controls on the
side of the unit when removing.
(5). To replace, install unit to instrument
panel with four screws and washers.
(6). Plug connector P509 into unit.
(7). If the unit installed is not the one
removed, adjust external controls on
unit (Ref. Intercom Microphone Audio
Level Adjustment, Para. VHF Comm
Transceiver Sidetone Signal Level
Adjustment, and Intercom Phone Audio
Level Adjustment below).
(8). (LH command helicopters only) Rein­
stall right side fairing to instrument
panel.
2. Integrated Interphone Communication
System Testing and Adjustments
NOTE:
In LH command helicopters only, access
the ICS control unit for the following tests
and adjustments by removing the right side
fairing from the instrument panel.
A. CE 500 HT − 3G ICS Control Unit Testing
Special Tools
(Ref. Section 91 − 00 − 00)
Item Nomenclature
ST1010 Volt-ohmmeter
N/A Resistor, 100 ohm, +5 percent, 2 watt
N/A AC signal generator
N/A Capacitor, 10 ufd.
Ensure that all electrical power
is OFF before performing the
following tests.
(1). Remove connector P509 from the ICS
control unit.
(2). Connect a 100 ohm, +5 percent, 2 watt
resistor between PHONE HI and
PHONE LO pins of connector J509 on
ICS control unit (Ref. Figure 101 or
Figure 102).
(3). Apply 28
±
0.5 Vdc to +28 Vdc and -28
Vdc (ground) pins of connector J509;
comply with polarity requirements (Ref.
Table 102).
(4). Connect an ac voltmeter between
PHONE HI and PHONE LO pins of
connector J509.
(5). Using an ac signal generator, perform
all the checks listed (Ref. Table 102).
NOTE:
Disconnect the signal generator and the
ac voltmeter before conducting the diode
continuity checks.
(6). Reinstall connector P509 to ICS control
unit.
B. Intercom Microphone Audio Level
Adjustment
(Ref. Figure 202) The ICS control potentiome­
ter (R8), located on the right end of the ICS
control unit, controls headset phone volume
during interphone operation by adjusting the
level of the microphone audio signal before the
CAUTION