(a)
Wing flaps, slats, and spoilers should be retracted during periods of snowfall and icing conditions. If it is necessary to operate these controls, ensure they are clear of accumulation before retraction.
NOTE: If an airplane arrives at the gate with flaps in a position other than fully retracted during a period of ice or snow conditions, those flaps which are extended must be inspected for ice or snow accumulation before retracting.
(b)
All control surfaces must be free of ice, snow, or frost. Following deicing operation check associated hinges, tracks and actuators for trapped moisture which could freeze. Apply deicing/anti-icing fluid for protection.
(c)
Balance panel bays (Fig. 203) must be free of ice and snow to permit free movement of the surfaces through their full travel. Following any deicing operation, these bays must be checked for ice, snow or pockets of water which could later freeze. Drains from balance panel bays should be checked to verify they are open. Prior to airplane operation, move control surfaces slowly through full travel to determine freedom of movement.
CAUTION: BALANCE PANEL SEALS WILL BE DAMAGED IF THE CONTROLS ARE OPERATED WHILE THEY ARE FROZEN. IF THERE IS REASON TO SUSPECT THE BALANCE PANEL SEALS ARE FROZEN, DO NOT APPLY FORCE, AND IF BY VISUAL INSPECTION BALANCE PANEL SEALS ARE FOUND TO BE FROZEN, DO NOT APPLY FORCE WITHOUT FIRST DEICING THE SEALS USING DEICING FLUID.
(d)
Position stabilizer (Fig. 203) from 0 to 2 units so that water or fluid will not run into balance panel bays.
(e)
Open leading edge devices and check for ice or snow.
(2)
Wing and Horizontal Tail Surfaces
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(a) Wing and horizontal tail surfaces must be free from ice, snow, and frost.
CAUTION: BE CAREFUL WHEN REMOVING ICE AND SNOW FROM WING AND TAIL SURFACES WHERE VORTEX GENERATORS ARE INSTALLED. FAILURE TO COMPLY COULD RESULT IN DAMAGE.
NOTE: Coatings of frost up to 1/8 inch in thickness on the lower wing surfaces caused by very cold fuel in the area of the wing tanks between the front and rear spar is permissible; however, all leading edge devices, control surfaces, tab surfaces, upper wing surfaces and balance panel cavities must be free of ice, snow or frost.
(b)
Leading edge surfaces must be free of ice, snow or frost. Check areas between stationary and movable surfaces for ice formation.
(c)
Both the right and left sides of the horizontal stabilizer must receive the same and complete deicing/anti-icing treatment.
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(3) Fuselage and Vertical Tail Surfaces
(a) Fuselage and vertical tail surfaces should be free of ice and snow to reduce aerodynamic drag and weight.
CAUTION: BE CAREFUL WHEN REMOVING ICE AND SNOW FROM FUSELAGE WHERE LIGHTS AND ANTENNA ARE LOCATED. FAILURE TO COMPLY MAY RESULT IN DAMAGE TO EQUIPMENT.
NOTE: Thin hoar frost is acceptable on the upper surface of the fuselage provided all vents and ports are clear. Thin hoar frost is a uniform white deposit of fine crystalline texture, which usually occurs on exposed surfaces on a cold and cloudless night, and which is thin enough to distinguish surface features underneath, such as paint lines, markings or lettering.
(b)
All snow must be removed from the nose radome area to prevent snow blowing back and obscuring pilots vision on takeoff.
(c)
Do not apply hot deicing fluid or hot water directly on pilots windshield or passenger window. Fluid may be allowed to run over windows after application to top of cabin as fluid will be cooled before reaching windows.
(d)
Any traces of deicing/anti-icing fluid on cockpit windows must be removed prior to departure, particular attention being paid to windows fitted with wipers. In addition any forward area from which fluid may flow back onto windshields during taxi and takeoff must be clean prior to departure.
(4)
Engines and APU
(a)
For personnel safety, engines and APU should not be operating during the deicing/anti-icing operations. However, if necessary, deicing/anti-icing may be accomplished with the engines and/or APU operating at idle speed if care is exercised to avoid spraying anti-icing/deicing fluids directly into the engine and/or APU inlet.
WARNING: PERSONNEL MUST OBSERVE DANGER AREAS IN FRONT OF OR IN BACK OF OPERATING ENGINE (REF CH. 70) AND IN APU EXHAUST STREAM (CHAPTER 49). INJURY OR LOSS OF LIFE MAY OCCUR TO PERSONNEL IN THESE AREAS. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737 AMM 飞机维护手册 SERVICING(66)
