FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 6. Corrosion, Inspection, and Protection | 4. Corrosion Preventative Maintenance | 6-51. Guidelines: Aircraft Operating Over Salt Water
9/8/98
SECTION 4. CORROSION PREVENTIVE MAINTENANCE AC 43.13-1B
6-50. GUIDELINES: ALL AIRCRAFT.
Corrosion prevention depends on a compre
hensive prevention and control plan, imple
mented from the start of operation of an air
craft, which includes:
a. Adequately-trained personnel in
(1) recognition of corrosion-inducing
conditions;
(2) corrosion identification techniques;
i. Replacing deteriorated or damaged
gaskets and sealants (using non-corrosive type
sealants) to avoid water intrusion and entrap
ment that leads to corrosion.
j. Minimizing the exposure of aircraft to
adverse environments by keeping the aircraft
in a hangar.
k. Periodic and frequent inspection of
areas where there are foamed plastics or other
absorbent material.
(3) corrosion detection, cleaning, and
treating; and
(4) lubrication and preservation of air
craft structure and components.
b. Inspection for corrosion on a sched
uled basis.
c. Thorough cleaning, inspection, lubri
cation, and preservation at prescribed intervals.
d. Prompt corrosion treatment after de
tection.
e. Accurate record-keeping and report
ing of material or design deficiencies to the
manufacturer and the Federal Aviation Ad
ministration (FAA).
f. Use of appropriate materials, equip
ment, and technical publications.
g. Maintenance of the basic finish sys
tems.
h. Keeping drain holes and passages
open and functional. Sealants, leveling com
pounds, miscellaneous debris, or corrosion in
hibitors should not block drain paths.
l. Daily draining of fuel cavities to re
move accumulated water and other foreign
matter.
m. Daily wipe-down of exposed critical
surfaces of hydraulic cylinders.
6-51. GUIDELINES: AIRCRAFT OP-
ERATING OVER SALT WATER. In addi
tion to the inspection and treatment prescribed
above, the following treatment shall be ap
plied:
a. Remove all traces of salt water and salt
water residue by thoroughly washing the air
craft with fresh water.
(1) After drying, coat the propeller,
hubs, blades and other unpainted or unpro
tected parts of the engine and its installation
parts by spraying or rubbing lightly with corro
sion preventive compound, Specification
MIL-C-16173, Grade 4.
(2) Apply this mixture on parts that
move or require some lubrication and on all
fittings subject to corrosion such as landing
gear retracting plungers, control surface
hinges, control cables, exposed rivets and
bolts, and other similar parts not protected by
Par 6-50
Page 6-13