MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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97-08-00
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Revision 12
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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.
PUBLIC ADDRESS AND SIREN SYSTEM
INITIAL INSTALLATION
1. Public Address and Siren System Initial
Installation
Procedures in this section may be performed at
operator's discretion and are applicable to all
Model 369D helicopters. These instructions
provide for the installation of the public
address and siren system, and include a
modification to the helicopter structure just
forward and below the right door on the pilot's
compartment.
A. Preparation for Installation
Preparation for installation of the public
address and siren system includes the follow­
ing:
(1). Check all electrical switches for OFF
position, and ensure that BATTERY-
OFF-EXT PWR switch is at OFF.
(2). Identify all components, including
attaching hardware, to be removed for
access to work areas. Protect compo­
nents from damage and foreign matter
until reinstalled.
B. Removal of Helicopter Equipment
Prior to installing the public address and siren
system, a limited number of items must be
removed from the helicopter to accommodate
the installation. Refer to applicable section
and perform the following:
(1). Remove left and right access doors from
pilot's floor compartment.
(2). If applicable, remove stowage box from
pilot's right side floor compartment.
(3). Remove seats from crew compartment.
(4). Remove hood and right side fairing
from instrument panel structure.
C. Modification of Helicopter
Modification of the helicopter consists of
providing an access port for the loudspeaker
output wire harness (-19 assembly) through
the fuselage skin at the pilot's right side floor
compartment as follows:
(1). Locate and mark hole center for cutout
in fuselage skin. Center of cutout is
located on right side of pilot's compart­
ment 2.06
±
0.06 in. (5.2324
±
0.1524
cm) below longeron at WL 15.75 and
1.89
±
0.06 in. (4.8006
±
0.1524 cm) aft
of Sta. 44.65 (Ref. Figure 901, view A).
(2). Using chassis punch or equivalent, cut
0.85 in. (21.59 mm) hole in fuselage
skin as required.
NOTE:
For installation of doubler on cutout in
fuselage skin, refer to Loudspeaker Assem­
bly.
D. Installation of System Components
Consumable Materials
(Ref. Section 91 − 00 − 00)
Item Nomenclature
CM318 Primer
Installation of the public address and siren
system includes procedures for installing the
amplifier on channel supports in the electron­
ics compartment, loudspeakers on brackets
just forward and below the right door of the
pilot's compartment, control unit and micro­
phone with support on the upper right side of
the instrument panel, circuit breaker on the
lower circuit breaker and switch panel, and
wire harness assemblies for the system. The
general notes that apply to the subsequent
procedures are as follows: