(b)
Open the ENGINE EPR circuit breakers on the P6 panel.
(c)
Fully advance No. 1 throttle. Check that both left and right wing anti-ice valves close and both left and right valve open lights glow brightly continuously.
(d)
Retard No. 1 throttle to idle stop position. Check that both left and right wing anti-ice valves open and both left and right valve open lights dim after one to three seconds.
(e)
Repeat steps (c) and (d) for No. 2 throttle. Results should be the same.
(f)
Close the ENGINE EPR circuit breakers on the P6 panel.
(g)
Open LANDING GEAR LIGHTS circuit breaker. Check that wing anti-ice switch automatically moves to OFF position and left and right wing anti-ice valves close.
(h)
Fully advance No. 1 throttle and place wing anti-ice switch in ON position. Check that left and right wing anti-ice valves open.
(i)
Retard No. 1 throttle and place wing anti-ice switch in OFF position. Check that left and right wing anti-ice valves close.
C. Duct Leakage Test
(1)
General
(a) Wing leading edge distribution ducts can be leak tested using either engine bleed, APU, or an external air supply. Air supply above 125°C will cause ground overheat thermal switch to cycle wing anti-ice control valve.
(2)
Prepare to Test Duct Leakage
(a)
Remove wing leading edge lower access panels.
(b)
Pressurize pneumatic duct.
1) If APU air is used: a) Close engine bleed and air conditioning pack valves. b) Check that manifold isolation valve switch is either in OPEN or AUTO
position. 2) If engine bleed air is used, operate engines at idle speed to keep air temperature as low as possible. 3) If external air is used: a) Connect air supply to ground pneumatic connection. (Air supply should be
sufficient to provide a minimum of 7-psi manifold pressure). b) Apply external electrical power. c) Close engine bleed and air conditioning pack valves. d) Check that manifold isolation valve switch is in either OPEN or AUTO
position.
(c)
Extend wing leading edge flaps and slats.
1) If APU or external air supply is used, refer to Chapter 27, Wing Leading Edge Flaps and Slats.
(d)
Check leading edge manifold and ducts for loose or broken brackets.
Apr 01/97 30-11-01
Page 503
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
(3)
Test Duct Leakage
(a)
Place wing anti-ice control switch in ON position.
(b)
Check distribution manifold and ducts for cracks, holes, and diffused leakage. Diffused leakage is allowable at duct seals and joints. Jet blasts are not permissible. Test for leakage by feeling in near vicinity of area being subjected to test.
WARNING: CARE SHOULD BE EXERCISED NOT TO PLACE HANDS DIRECTLY ON HEATED DUCTS. DUCTS MAY REACH APPROXIMATELY 125°C IN NORMAL OPERATION AND UP TO 450°F IF OVERHEAT PROTECTION FAILS. SERIOUS BURNS CAN RESULT FROM DIRECT CONTACT WITH DUCTS.
(c)
Check leading edge flap skins for proper sealing (no leakage) at joints.
(d)
Check leading edge flap and slat skin openings for diffused airflow and that openings are free of sealant and foreign matter.
CAUTION: BLOCKED SKIN OPENINGS ALLOW ACCUMULATION OF WATER WHICH ACCELERATES SKIN CORROSION.
(e)
Place wing anti-ice control switch in OFF position.
(4)
Restore Airplane to Normal
(a)
Retract wing leading edge flaps and slats (Ref Chapter 27, Leading Edge Flaps and Slats).
(b)
Remove air supply.
(c)
If external air supply was used, determine if there is any further need for electrical power on airplane. If not, remove electrical power.
(d)
Install wing leading edge lower access panels.
D. Ground Operational Test with Engine Power
NOTE: You can also do this test with APU power. Paragraph E. provides a procedure, which uses this option.
(1) Prepare to Test Wing TAI System.
(a)
Start engines in accordance with engine start procedure (Ref Chapter 71, Power Plant).
(b)
With the engines set idle and power available at 115 volts ac transfer bus No. 1 and No. 2, and 28 volts dc T/R bus No. 1, check that the following circuit breakers are closed: 1) ENG NO. 1 NACELLE & WING ANTI-ICE 2) ENG NO. 2 NACELLE & WING ANTI-ICE 3) ENG NO. 1 & WING ANTI-ICE CONTROL
(c) 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：737 AMM 飛機維護手冊 防冰和排雨 ICE AND RAIN PROTECTION(13)
