Cessna 172 Skyhawk SERIES, Руководство по обслуживанию

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CESSNA AIRCRAFT COMPANY
SINGLE ENGINE
STRUCTURAL REPAIR MANUAL
FIREWALL REPAIR
1. General
A. The fi rewall is constructed of 0.016 inch, 18-8 corrosion resistant, annealed stainless steel sheet.
(1) A typical fi rewall patch is illustrated in Figure 801.
(2) A typical repair to the interior fi rewall angle is illustrated in Figure 802.
2. Material
NAME NUMBER MANUFACTURER USE
Firewall Sealant
AMS 3374 Pro-Seal #700-A Loctite Aerospace
Bay Point, CA 94565 Firewall sealant
3. Repairing the Firewall Assembly
A. Firewall sheets may be repaired by removing damaged material and splicing in a new section. The
splice must be lapped over the old material, sealed and secured with steel rivets.
(1)
Patches, splices and joints must be repaired using MS20450 steel rivets.
B. Following any repair to the fi rewall assembly, seal the damaged areas as follows:
(1) Clean area on surface to be sealed with methyl propyl ketone.
(2) Mix one part of catalyst thoroughly with 100 parts of Pro-Seal No. 700 base.
NOTE: Sealant should be mixed by weight. It is important that accelerator be completely and
uniformly dispersed throughout the base compound.
(3) Using a spatula, caulking gun, or fl ow gun, apply a fi llet of sealer along cracks, seams, joints,
and rows of rivets.
NOTE: If the sealant is applied before the parts are mated, use enough sealing compound
to completely
fi ll the joint, and wipe away excess after parts are mated.
NOTE: If the sealant is applied with a brush or a brush fl ow gun, more than one coat of sealant
will be necessary on very porous material. Sealant should be allowed to air-dry 10
minutes between coats.
53-40-00
Page 801
© Cessna Aircraft Company
Jun 1/2005