FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 9. Aircraft Systems and Components | 1. Inspection and Maintenance of Landing Gear | 9-7. Landing Gear Components
AC 43.13-1B CHG 1
9/27/01
gency systems employ either mechanical, pres-
sure-bottle, or free-fall extension capabilities.
Check for the proper safeties on triggering
mechanisms, and for the presence of required
placards, and necessary accessories such as
cranks, levers, handles, etc. Emergency blow-
down bottles should be checked for corrosion
damage, and then weighed to see if the bottle
is still retaining the charge.
9-7. LANDING GEAR COMPONENTS.
The following items are susceptible to service
difficulties and should be inspected.
a. Shock Absorbers. Inspect the entire
shock-strut for evidence of leaks, cracks, and
possible bottoming of the piston, as this con-
dition causes overloading of landing-gear
components and contributes to fatigue cracks.
Check all bolts, bolt holes, pins, and bushings
for condition, lubrication, and proper torque
values. Grease fitting holes (pressure-type) are
especially vulnerable to cracks and cross-
threading damage. Check all safety wire and
other locking devices, especially at the main
packing gland nuts.
(1) When assembling shock-struts, use
the correct type and number of new “O”-rings,
Chevron seals, and backup rings. Use only the
correct filler valve core assembly, and follow
the manufacturer’s instructions when servicing
with fluid and air. Either too much or too little
air or oil will affect aircraft handling charac-
teristics during taxi, takeoff, and landing, and
can cause structural overloads.
(2) Shock cords and rubber discs dete-
riorate with age and exposure. When this type
of shock absorber is used, inspect for general
condition; i.e., cleanliness, stretching, fraying,
and broken strands. These components should
be kept free of petroleum products as they ac-
celerate deterioration of the rubber.
b. Nose Gear Assembly. Inspection of
the steering mechanism should include torque-
links (scissors), torque-tubes, control rods and
rod-end bearings, shimmy dampers, cables,
and turning stops. In addition, check all nose
landing gear components, including mud
scrapers and slush deflectors, for damage.
(1) Towing of some aircraft with the
rudder locks installed, may cause damage to
the steering linkage and rudder control system.
Exceeding the steering or towing stop limits
should be followed by a close inspection of the
entire nose steering assembly. A broken
steering stop will allow turning beyond the de-
sign limit, transmitting excessive loads to
structures, and to the rudder control system. It
is recommended that the nose steering arc lim-
its be painted on the steering collar or fuselage.
(2) Inspect shimmy dampers for leakage
around the piston shaft and at fluid line con-
nections, and for abnormal wear or looseness
around the pivot points. Also check for proper
rigging, “bottoming” of the piston in the cylin-
der, and the condition of the external stops on
the steering collar.
c. Tail Wheels. Disassembly, cleaning,
and re-rigging of tail wheels are periodically
necessary. Inspect them for loose or broken
bolts, broken springs, lack of lubrication, and
general condition. Check steerable tail wheels
for proper steering action, steering-horn wear,
clearances, and for security and condition of
steering springs and cables.
d. Gear Doors. Inspect gear doors fre-
quently for cracks, deformation, proper rig-
ging, and general condition. Gear door hinges
are especially susceptible to progressive
cracking, which can ultimately result in com-
plete failure, allowing the door to move and
cause possible jamming of the gear. This con-
dition could also result in the loss of the door
during flight. In addition, check for proper
safetying of the hinge pins and for distorted,
sheared, loose, or cracked hinge rivets. Inspect
the wheel wells for improper location or rout-
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