MD Helicopters 369-500, Инструкция по техническому обслуживанию

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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Revision 7
95-10-10
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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.
NOTE:
D
Either of two types of circuit breaker
switches may be encountered. Both are
MS24509-A basic circuit breakers, but
some may be of 7.5 ampere rating, and
others may be of 15 ampere rating. These
are MS24509-A-7 and MS24509-A-15,
respectively. Be sure to replace this cir­
cuit breaker with one of identical ampere
rating.
D
The bushing mount MS24509-A configu­
ration circuit breaker switch is secured
with one MS25082-B21 nut, one
MS35333-121 lockwasher and one
MS25081-4 key washer. These fasteners
are usually furnished with a new circuit
breaker, but they may be obtained sepa­
rately as required. The MS24509-A se­
ries circuit breakers are furnished with
MS35206-241 screws and MS35338-42
lockwashers for terminal lug attachment.
(1). Remove two screws and lockwashers
from terminals of circuit breaker switch
and remove wires.
NOTE:
On the edgelighted switch panel, re­
move the panel subassembly to gain access
to circuit breaker bushing nut. On the Slim-
Line instrument panel, R/H command T-
Panel installation without center console or
L/H command T-Panel, remove the switch
panel.
(2). Remove nut and lockwasher from
bushing of circuit breaker switch.
(3). Slide circuit breaker switch rearward
through hole in panel.
(4). Replace circuit breaker switch in
reverse order of removal.
(5). Install key washer on bushing so key
extends through small hole in panel
adjacent to bushing hole.
8. Electrical Bond Jumper Replacement
On later 369D helicopters equipped with the
Slim-Line instrument panel, circuit breaker
switches CB119 and CB120 are strapped
together with the wiring assembly to provide
+28 Vdc to the pitot tube circuit.
In the diagram, the wiring assembly is designated
P506U16. The P506U16 jumper is secured to ter­
minal 1 on each of the two circuit breaker switches
CB119 and CB120 with MS35206-241 screws and
MS35338-42 lockwashers.
9. Heated Pitot Tube Functional Test
Perform the following tests after installation
or maintenance of the heated pitot tube
assembly and before resumption of flight
operations, to ensure airworthiness.
(1). Attach auxiliary power unit (APU).
(2). Set BAT/OFF/EXT PWR switch (S2) to
EXT PWR (or set master switch (S2) to
EXT).
(3). Set PITOT HEAT circuit breaker switch
(CB120) (or PITOT HTR circuit breaker
switch (CB129)) to upper position.
(4). Check for rise in pitot tube tempera­
ture. Tip of pitot tube should be hot
after five minutes.
(a). If pitot tube is not hot, perform
voltmeter check.
(b). If pitot tube is hot, disregard voltme­
ter check and proceed.
(5). Attach positive lead of voltmeter to
terminal 1 of circuit breaker switch
CB120 (or CB129 on helicopters with
edgelighted switch panel) and connect
negative lead to a good chassis ground.
Voltmeter should in26 Vdc to
+28 Vdc.
(a). If voltmeter ind26 Vdc to +28
Vdc, troubleshoot heated pitot tube
installation (Ref. Table 201).
(b). If voltmeter fails to in26 Vdc
to +28 Vdc, verify proper test configu­
ration (APU connected and circuit
breakers set as instructed at begin­
ning of this procedure); then refer to
helicopter electrical system trouble­
shooting procedures (Ref. Chap 96) if
necessary.
(6). Set BAT/OFF/EXT PWR switch (or
MASTER switch) to OFF.
(7). Set PITOT HEAT circuit breaker switch
(of PITOT HTR circuit breaker switch)
to OFF.