FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 6. Corrosion, Inspection, and Protection | 5. Visual Corrosion Inspection Guide for Aircraft | 6-67. Bilge Areas
9/8/98
AC 43.13-1B
SECTION 5. VISUAL CORROSION INSPECTION GUIDE FOR AIRCRAFT
6-63. GENERAL. This guide provides a
general inspection checklist for those parts or
surfaces that can be visually inspected without
disassembly of the aircraft. It is intended for
use in establishing corrosion inspection areas
for which the manufacturer has not provided a
recommended corrosion inspection program.
The manufacturer’s recommended corrosion
inspection program will take precedence over
this guideline. These inspections should be
accomplished in conjunction with other pre
ventive maintenance.
6-64. EXHAUST TRAIL AREAS.
a. Visually inspect paint in areas of the
exhaust trails for damage.
b. Remove any foreign material from
bilge and inspect for corrosion.
6-68. WHEEL WELLS AND LANDING
GEAR. Inspect wheel well area and landing
gear components for damage to exterior finish
coating and corrosion. Particular attention
should be given to exposed surfaces of struts,
oleos, arms, links, and attaching hardware;
axle interiors, exposed position indicator
switches and other electrical equipment; crev
ices between stiffeners, ribs, and lower skin
surfaces; magnesium wheels, particularly
around bolt heads, lugs, and wheel web areas;
and exposed rigid tubing at “B” nuts and fer
rules under clamps, and tubing identification
tapes.
b. Visually inspect under fairings,
around rivet heads, and in skin crevices, for
corrosion in areas of engine exhaust trail.
6-65. BATTERY COMPARTMENTS
AND BATTERY VENT OPENINGS.
a. Inspect battery compartment for
electrolyte spillage, corrosion, and condition of
protective paint.
b. Inspect area around battery vent for
corrosion.
6-66. LAVATORIES AND GALLEYS.
Inspection areas around lavatories, sinks, and
ranges for spillage and corrosion. Pay par
ticular attention to floor area and the area be
hind and under lavatories, sinks, and ranges.
6-67. BILGE AREAS.
a. Inspect bilge areas for waste hydraulic
fluids, water, dirt, loose fasteners, drill chips,
and other debris.
6-69. EXTERNAL SKIN AREAS.
a. Inspect external skin surfaces for
damage to protective finishes and corrosion.
b. Inspect around fasteners for damage
to protective finishes and corrosion.
c. Inspect lap joints for bulging of skin
surface, which may indicate the presence of
corrosion between the faying surfaces. Skin
cracks and/or dished or missing fastener heads
may also indicate severe corrosion in bonded
joints.
d. Inspect area around spot welds for
bulges, cracks, or corrosion.
e. Inspect piano type hinges for corro
sion. When piano hinges are inspected they
should be lubricated and actuated through sev
eral cycles to ensure complete penetration of
the lubricant.
Par 6-63
Page 6-15