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 | 9-3. Cleaning and Lubricating
9/27/01
AC 43.13-1B CHG 1
CHAPTER 9. AIRCRAFT SYSTEMS AND COMPONENTS
SECTION 1. INSPECTION AND MAINTENANCE OF LANDING GEAR
9-1. GENERAL.
a. The landing gear on aircraft may be
fixed or retractable. A fixed gear may be
wheels, floats, or skis; and for amphibians a
combination of floats and wheels.
b. Retractable gear on aircraft is usually
operated with hydraulic or electric power, al-
though some models of light general aviation
aircraft have manual retract systems operated
by a lever in the cockpit.
(1) In addition to the normal operating
system, emergency systems are usually pro-
vided to ensure that the landing gear can be
lowered in case of main-system failure.
(2) Emergency systems consist of
backup hydraulic systems, or stored nitrogen
gas bottles that can be directed into actuating
cylinders, mechanical systems that can be op-
erated manually, or free-fall gravity systems.
Wear points, such as landing gear up-and-
down latches, jack-screws, door hinges, pul-
leys, cables, bellcranks, and all pressure-type
grease fittings, should be lubricated after every
cleaning operation.
To prevent possible failure of a component due
to incompatibility or breakdown of the grease,
the following should be observed:
1. Use only greases approved for use by
the product manufacturer.
2. Never mix different kinds of grease
without approval from the product
manufacturer.
3. Follow the manufacturer’s instructions
or FAA approved process for cleaning,
purging, and lubricating of the compo-
nent.
To obtain proper lubrication of the main sup-
port bushings, it may be necessary to jack the
aircraft.
9-2. GENERAL INSPECTION. A thor-
ough inspection of the landing gear involves
the entire structure of the gear, including at-
tachments, struts, wheels, brakes, actuating
mechanisms for retractable gears, gear hydrau-
lic system and valves, gear doors, and all asso-
ciated parts. The manufacturer’s inspection
procedures should be followed where applica-
ble.
9-3. CLEANING AND LUBRICATING.
It is recommended that only easily removable
neutral solutions be used when cleaning land-
ing gear components. Any advantage, such as
speed or effectiveness, gained by using clean-
ers containing corrosive materials, can be
quickly counteracted if these materials become
trapped in close-fitting surfaces and crevices.
NOTE: Any time the aircraft is on
jacks, check the landing gear main
support bushings for wear. Consult
the aircraft manufacturer’s overhaul
manual for specific wear tolerances.
During winter operation, excess grease may
congeal and cause increased loads on the gear
retraction system, electric motors, and hydrau-
lic pumps. This condition can lead to compo-
nent malfunctions; therefore, it is recom-
mended that cleanliness be stressed during and
after lubrication.
9-4. FIXED-GEAR INSPECTION. Fixed
landing gear should be examined regularly for
wear, deterioration, corrosion, alignment, and
other factors that may cause failure or unsatis-
factory operation. During a 100-hour or an-
Par 9-1
Page 9-1