Tire treads should be inspected to determine the
extent of wear. The maximum allowable thread wear
for tires without wear depth indicators is when the
tread pattern is worn to the bottom of the tread groove
at any spot on the tire. The maximum allowable tread
wear for tires with tread wear indicators is when the
tread pattern is worn either to the bottom of the wear
depth indicator or the bottom of the tread groove.
These limits apply regardless of whether the wear is
the result of skidding or normal use.
The tread and sidewall should be examined for
cuts and embedded foreign objects. Figure 11-17
shows the method for measuring the depth of cuts,
cracks, and holes. Glass, stones, metal, and other
materials embedded in the tread should be removed to
prevent cut growth and eventual carcass damage. A
blunt awl or screwdriver maybe used for this purpose.
You should be careful to avoid enlarging the hole or
damaging the cord body fabric.
WARNING
When you are probing for foreign objects,
be sure you keep the probe from
penetrating deeper into the tire. Objects
being pried from the tire frequently are
ejected suddenly and with considerable
force. To avoid eye injury, safety glasses or
a face shield should be worn. A gloved
hand over the object may be used to deflect
it.
Aircraft should not be parked in areas where the
tires may stand in spilled hydraulic fluids, lubricating
oils, fuel, or organic solvents.
If any of these
materials is accidentally spilled on a tire, it should be
immediately wiped with a clean, absorbent cloth. The
tires should then be washed with soap and thoroughly
rinsed with water.
Extra care should be taken when you inspect
mounted helicopter tires.
Because of the long
intervals between tire changes, helicopter tires are
subject to weather and UV damage.
Dismounted Inspection
Whenever a tire has been subjected to a hard
landing or has hit an obstacle, it should be removed in
accordance with the applicable MIMs and dismounted
for a complete inspection to determine if any internal
damage has occurred.
The tire beads should be
spread, and the inside of the tire inspected with the aid
of a light. If the lining has been damaged or there are
other internal injuries, the tire should be removed
from service. You should check the entire bead area
and the area just above the bead for evidence of rim
chafing and damage. Check the wheel for damage
that may damage the tire after it is mounted.
AIRCRAFT TIRE MAINTENANCE
Aircraft tire inspection and maintenance have
become more critical through the years because of
increased aircraft weight and higher landing and
Figure 11-17.—Method of measuring depth of cuts, cracks, and holes.
11-18
