S 975-032
(12)
Use Fig. 503 to correct pressures for ambient temperature and pressure.
S 975-033
(13)
Make a record of corrected pressures (Fig. 504).
S 975-034
(14)
Compare corrected gage pressures to minimum acceptable pressures (Fig. 504).
S 215-035
(15)
If the test port pressures are lower than the minimum acceptable pressures, look for leaks at the duct joints or blockage in the system.
S 435-037
(16)
Install the IRUs on the E3-5 shelf (AMM 34-28-31/401).
S 415-046
(17)
Install the "REMOVE FOR COOLING TEST ONLY" foil markers over the test ports on the cooling supply ducts to the E3-5 shelves.
S 865-043
(18)
Remove the electrical power, if it is not necessary (AMM 24-22-00/201).
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
EFIS COOLING SYSTEM - INSPECTION/CHECK
______________________________________
1. General_______
A. The Electronic Flight Instrument System (EFIS) contains these electrical components:
(1)
EHSI - Electronic Horizontal Situation Indicator
(2)
EADI - Electronic Attitude Director Indicator
B. The EFIS cooling system keeps the necessary flight and navigation units cool.
C. A decrease of cool air to the EFIS causes the deterioration of the data that is shown by the EADI and the EHSI.
TASK 21-58-02-216-001
2. Do an Inspection of the EFIS Cooling System___________________________________________
A. References
(1)
AMM 21-00-00/201, Air Conditioning
(2)
AMM 21-58-61/201, EFIS Cooling Air Cleaner
(3)
AMM 21-58-91/201, EFIS Cooling Check Valves
(4)
AMM 24-22-00/201, Manual Control
(5)
AMM 34-22-21/401, Electronic Attitude Director Indicator
(6)
AMM 34-22-31/401, Electronic Horizontal Situation Indicator
B. Access
(1)
Location Zone
101 Control Cabin - Left
102 Control Cabin - Right
203 Nose Wheel Well
(2)
Access Panels
1103L Forward Access Door
3103R Forward Nose Wheel Well Panel
3105R Forward Nose Wheel Well Panel
C. Prepare to do an Inspection of the EFIS Cooling System
S 866-002
(1)
Open these circuit breakers and attach DO-NOT-CLOSE tags:
(a) P18 Panel
1) NORM COOLING FAN CONT
2) ALT COOLING FAN CONT
3) L EFIS SYM GEN
4) R EFIS SYM GEN
5) L EFIS CONT PANEL
6) R EFIS CONT PANEL
7) L EHSI
8) R EHSI
9) L EADI
10) R EADI
(2)
Put the L IRS control switch in the OFF position.
S 866-003
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. APLS WITH EFIS ú
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
LOW FLOW SENSOR
E3-5 SHELF NOT SHOWN FOR CLARITY
EFIS Cooling System Installation
Figure 601
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ú ú 01 Page 602 ú Nov 15/91
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
S 866-004
(3)
Put the R IRS control switch in the OFF position.
S 016-006 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 空调 AIR CONDITIONING 2(91)
