NOTE: You should ensure bearings are
completely dry before packing (them with
You should also spread a thin layer of grease on
the bearing cups.
Inspect the grease retainers for
evidence of deterioration, contamination, or water
You should replace them if necessary.
Presoak the retainers with VV-L-800 oil prior to
Refer to the NA 01-1A-503 manual for more
detailed information on wheel bearing maintenance.
Corrosion and Physical Damage Blendout
Limited and isolated corrosion and physical
damage should be blended. Wheel rims, outside ends
of bearing hubs, nicks, gouges, and pock marks are
not considered significant unless the defect is deeper
than 0.020 of an inch. The defect should not be
blended out unless there is active corrosion in the
However, all burrs must be removed.
Corrosion or other defects should be blended out not
to exceed a maximum of one-sixteenth of an inch. All
damage must be removed within this allowance. The
maximum depth of blendout for all other wheel areas
is 0.010 of an inch.
The rims, bearing hub ends, and tire bead area can
be blended out with a medium or fine cut, half-round
or round tile. You should lightly file the damaged
area to remove the defects. After the defects have
been removed, you should hand polish the areas with
320 or finer grit aluminum oxide (P-C-451). All file
marks should be removed. The areas should be
painted according to NAVAIR 04-10-1 and NAVAIR
Matching Wheel Halves
Split rim wheels are manufactured and assembled
as a matched assembly. Each half will have the same
serial number. If a wheel half is rejected at the IMA,
the remaining half may be matched to a serviceable
replacement to make a complete assembly. When you
combine unmatched wheel halves, each half must
have the same part number. Every effort should be
made to keep the manufacture dates of each half as
close as possible. Each half of this wheel assembly
will now have different serial numbers, which is
Recognize the proce-
dures for dismounting, mounting, and
inflating aircraft tires. You should be able to
identify various tire markings and determine
preventive maintenance requirements
indicated by tire tread wear.
Proper care and maintenance of tires have always
been important items in aircraft maintenance.
Because of the modern fast-landing aircraft, careful
tire maintenance has become increasingly important.
Aircraft tires are built to withstand a great deal of
punishment, but only by proper care and maintenance
can they give safe and dependable service.
These designations refer to construction features
and the types of tire casings with which they are used.
The dimensions used to identify wheels are not
necessarily the dimensions of the wheels themselves.
Instead, they refer to dimensions of the tire. Tire size
designations are discussed later.
Figure 11-10 shows the construction details of a
tube-type aircraft tire. Tubeless tires are similar to
tube tires except they have a rubber inner liner that is
mated to the inside surface of the tire. The rubber
liner helps retain air in the tire. The beaded area of a
tubeless tire is designed to form a seal with the wheel
Wear indicators have been built into some
tires as an aid in measuring tread wear. These
indicators are holes in the tread area or lands in the
bottom of the tread grooves.
The cord body consists of multiple layers of nylon
with individual cords arranged parallel to each other
and completely encased in rubber. The cord fabric
has its strength in only one direction. Each layer of
coated fabric constitutes one ply of the cord body.
Adjacent cord plies in the body are assembled with
the cords crossing at nearly right angles to each other.
This arrangement provides a strong and flexible tire
that distributes impact shocks over a wide area. The
functions of the cord body are to give the tire tensile
strength, to resist internal pressures, and to maintain
The tread is a layer of rubber on the outer surface
of the tire. It protects the cord body from abrasion,
cuts, bruises, and moisture.
It is the surface that
contacts the ground.