(f) Repair may be made using RTV 106 alone (for field rework only).
NOTE: Do not use RTV 106 where the depth of rework is more
____
than 0.25 inch.
S 358-042-N00
(2) If you can put a one inch diameter dowel into the area where there is no insulation, do these steps:
(a)
Examine the honeycomb panel face sheet for delamination. 1) Repair the honeycomb if delamination has occured.
(b)
Repair the loose insulation before the insulation falls off.
(c)
Replace the insulation with the same or more than the initial thickness.
(d)
Seal all of the damaged areas with BMS 10-102, Type II.
S 358-045-N00
(3) Use the major damage repair procedure if the damaged areas of the insulation are less than two inches between the dowel centers.
(a) The thicknesses of the insulation layer are shown on Fig. 802. 1) The areas coated to keep the structure serviceable during operation are shown.
2) Other areas are coated to decrease the damage and repair costs if a duct rupture or fire occurs.
H. Repair of Major Damage and Insulation that is Gone - Molded Patch Method.
S 358-049-N00
(1) Do the steps that follow for repair of the major damage and
insulation that is gone.
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES /MAINTENANCE MANUAL ////////////////////////
0.270
INCH
A
0.230
PRECOOLER INLET DUCT
A
FIREWALL
AREA
0.140
INCHTHRUST 0.120
REVERSER
SLEEVE
BC
0.100
INCH0.080
FAN DUCT
COWL
STEEL SKIN DO NOT APPLY CROWN METRO INSULATION
0.140
INCH0.120
LOWER
BIFURCATION
SEE A FWD
BC RIGHT HAND COWL
A-A
B-B
Insulation Coating Thickness
Figure 802 (Sheet 1)
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0.270 0.230 INCH
STEEL SKIN - DO CROWN METRO INSULATION NOT APPLY THE FIREWALL AREA
D D INCH 0.100 0.080
INCH 0.140 0.120
INCH0.120 0.150
FWD
LEFT HAND COWL C-C
NOTE: DO NOT APPLY TO THE FACE OFTHE COMPRESSION PADS, OR LATCH KEEPER. DO NOT OBSTRUCT OR PLUG DRAIN PATHS.
D-D
Insulation Coating Thickness Figure 802 (Sheet 2)
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NOTE: This repair procedure uses molded patches of insulation with
____ the same thickness or greater than that of the original insulation on the cowl.
CAUTION: OBEY THE INSTRUCTIONS IN THE PROCEDURE TO CLEAN THE REPAIR
_______ AREAS. DO NOT USE SOLVENTS TO CLEAN THE REPAIR AREA BECAUSE CONTAMINATION OF THE INSULATION CAN OCCUR EASILY. DO NOT CAUSE SCRATCHES ON THE BASE METAL. IF YOU DO NOT OBEY THESE INSTRUCTIONS, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT.
(a)
Cut through the top coat layer of the insulation with a sharp knife that is not metal. 1) Remove the insulation with a scraper that is not metal. 2) Remove the loose material with a soft brush or a clean
cheesecloth.
(b)
Apply the primer to the repair area. 1) Apply a constant layer to make the surface wet. 2) Dry the primer for 30 minutes at 75 |10°F. 3) The maximum cure time before you can apply a top coat layer
over the primer is two hours at 50 percent (or greater) humidity.
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