H26110 H26084 H26080 G42770
Middle Pane Damage Due to Window Clip 500
56-21-0 Figure 601 Jun 20/84
Page 602
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
500 Alternate Method of Measuring Depth of Crazing
Jun 20/84 Figure 602 56-21-0
Page 603
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
Window Surface Crack Development - Typical 500
56-21-0 (Outer Pane Stretched Acrylic) Jun 20/84
Page 604 Figure 603
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500 Passenger Compartment Window Inspection
Oct 20/89 Figure 604 56-21-0
Page 605
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
B. Materials and Equipment
(1) Optical Micrometer - Model 966A1
Edwards Aerospace Company
1841 Business Pkwy
Ontario, CA 91761
Telephone (714) 923-3533
Fax (714) 923-6781
C. Examine Windowpanes
(1) Examine windowpanes for cracks.
CAUTION: DO NOT PRESSURIZE AIRPLANE WITH CRACKED MIDDLE PANE. PRESSURIZATION INTEGRITY OF FUSELAGE WITH ONE PANE CRACKED IS CRITICAL, BECAUSE FAIL-SAFE FEATURE HAS BEEN ELIMINATED.
(a)
Replace any cracked middle pane.
(b)
Minimum thickness for middle pane is 0.157 inch.
(c)
Replace outer pane if crack is deep enough that pane thickness after rework will be less than the following minimum thickness:
NOTE: Cracks 0.050 inch deep or deeper will require replacement of outer pane.
Cracks in outer pane can develop from scratches or crazing (Fig. 603).
1) 0.265 inch minimum thickness for all outer passenger windowpanes in fuselage.
(d)
Exact depth of crack may be measured with an optical micrometer. To obtain correct measurement, multiply micrometer reading by acrylic plastic index of refraction (1.49).
(e)
Any accurate method for determining crack depth is acceptable (Fig. 602).
(2) Examine windows for crazing.
CAUTION: DO NOT PRESSURIZE AIRPLANE WITH CRAZED MIDDLE PANE. PRESSURIZATION INTEGRITY OF FUSELAGE WITH MIDDLE PANE CRAZED IS CRITICAL, BECAUSE FAIL-SAFE FEATURE HAS BEEN ELIMINATED.
(a)
Replace any crazed middle pane.
(b)
Replace outer pane if depth of crazing exceeds 0.03 inch on the bevel edge.
NOTE: A 0.03 inch maximum depth of crazing on the bevel edge is allowable providing a minimum thickness of window is 0.265 inch and a maximum width of bevel is 0.550 inch (Fig. 604).
(c)
Replace outer pane if depth of any single craze or crack equals or exceeds 0.05 inch.
(3)
Examine windows for scratches.
(a)
Minor scratches in outboard surface of outer panel and inboard surface of inner pane may be made less visible by waxing.
(b)
Scratches may be removed from surfaces of panes (Ref AR).
(4)
Examine windows for in-plane cracking (formerly identified as delamination).
(a)
Replace outer pane whenever edge in-plane cracking can be seen with window installed.
(b)
Replace pane if in-plane cracking exceeds 0.55 inch from edge of removed pane.
(c)
In-plane cracking of outer pane at any place other than its edges, is often accompanied by chipping. Outer pane should be replaced if in-plane cracking or chips exceed the following limits: 1) Maximum chip depth -- 0.05 inch 2) Maximum size of in-plane cracking -- 0.40 inch diameter 3) Minimum distance between defects -- twice maximum damage diameter
(d)
No in-plane cracking permitted in middle pane.
(5)
Examine windows for chipping.
(a) Refer to above in-plane cracking examination paragraph, for limits for chipping in outer windowpane.
(6)
Examine windows for erosion.
(a) Erosion or chipping can occur at window forward edge. Structurally this is acceptable. However, if appearance becomes objectionable, window may be repaired to remove roughness. 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 WINDOWS 风挡/窗户(29)
