MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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[ Chapter 95 TOC ]
95-50-00
Page 201
Revision 7
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.
MISCELLANEOUS INSTRUMENTS
MAINTENANCE PRACTICES
1. Outside Air Temperature Indicator
(Ref. Figure 201 for 369D helicopters,
Figure 202 for 369E/FF - 500/600N helicop­
ters) The outside air temperature (OAT)
indicator is mounted on the canopy just above
the instrument panel. The gauge temperature
bulb is protected from direct sunlight by a
sunshield. The dial indicates outside air
temperature in both Fahrenheit and Centi­
grade.
2. Outside Air Temperature Indicator
Replacement
(Ref. Figure 201 or Figure 202)
(1). Hold OAT indicator dial firmly and
remove sunshield from thermometer
stem. Remove dished washer and
rubber mounting washer, spacer and
seal from stem; then remove indicator
from canopy. Remove spacer and inner
mounting seal from stem.
(2). Remove sun shield, dished washer and
outer rubber washer from replacement
indicator and install indicator in canopy
with inner spacer.
(3). Rotate indicator dial for correct reading
position, install seal, outer spacer, outer
rubber washer, dished washer and sun
shield, and securely hand-tighten sun
shield. Note spacer positioning.
3. Running Time Meter
(Ref. Figure 203) The running time meter is
basically an electric clock that provides an
accurate record of engine and/or transmission
operating time in hours and tenths of hours.
The meter operates whenever an oil pressure
switch in the main rotor transmission is closed
by transmission operating oil pressure.
The meter re28 Vdc power from the
INST 5 ampere circuit breaker. The circuit is
completed to ground through the normally-
open contacts of the main rotor transmission
oil pressure switch (S203). A second set of
normally-closed contacts in the switch
operates the XMSN oil pressure warning light
when below normal operating pressure exists.
(Slim-Line and most T-panels) The running
time meter is installed in a cover panel on the
left side of the instrument panel structure just
below floor level and is visible from outside the
helicopter.
(R/H command T-panels in TOW-equipped
helicopters only) The running time meter is
installed on the right side of the instrument
panel structure.
4. Running Time Meter Replacement
(Ref. Sec. 95-00-00 for general instrument
replacement procedures.)
NOTE:
If wire connections at the transmission
oil pressure switch are disconnected for any
reason, reconnect them as shown in Chapter
96 wiring diagram. If wires are reversed,
the running time meter will operate on low
oil pressure and transmission low oil pres­
sure warning light will operate on high oil
pressure.
5. Clocks
The Models A11-90W-ET and 1020 clocks are
stem-wound and stem-set. These are mechan­
ical eight-day clocks. They provide an analog
time readout and are not intended for precise
navigation.
The Model 99500-ELT quartz electric clock
also provides an analog time readout. This
clock has a fused +28 Vdc power input
terminal tied to the hot side of the battery
relay and an u28 Vdc input for
internal lighting.
6. Wiring Troubleshooting − Quartz Electric
Clock
(Ref. Figure 204)