· Tread separation and bulges that exceed 1 inch
· Tires saturated with rubber deteriorating liquids
· Tires exposed to excessive heat
All tires removed from service, which are not
condemned, are potentially rebuildable and should be
condition coded "F" (BCM-1) and returned to the
supply department for retreading. The number of
retreads a carcass may receive will be based solely on
carcass integrity as determined by the inspection
TIRE PREVENTIVE MAINTENANCE
Figure 7-27.--Rapid tread wear caused by overinflation.
Debris on runways and in parking areas causes tire
failures, and results in many tires being removed long
condition remedied before the tire is ruined. Some of
before they reach full service life. It is important that
the common causes of uneven tread wear are
those areas be kept clean at all times.
underinflation, overinflation, misalignment, and
When you ground handle an aircraft, do not pivot
with one wheel locked or turn sharply at slow speeds.
This not only scuffs off the thread, but also causes
the tire to wear rapidly and unevenly at the outer edges
internal separation of the cords. Always be sure the
of the tread, as shown in figure 7-26. An underinflated
aircraft is moving before you attempt a turn. This
tire develops higher temperatures during use than a
allows the tire to roll instead of scrape.
properly inflated tire. This can result in tread separation
or blowout failure.
You should make every effort to prevent oil, grease,
hydraulic fluid, or other harmful materials from coming
OVERINFLATION.--Overinflation reduces the
in contact with the tires. When there is a chance that
tread contact area, causing the tire to wear faster in the
harmful materials may come in contact with the tires
center, as shown in figure 7-27. Overinflation increases
during maintenance, they should be protected by
the possibility of damage to the cord on impact with
covers. To clean tires that have come in contact with oil,
foreign objects and arresting cables on the runway or
grease, or other harmful material, you should use a
brush or cloth saturated in a soap and water solution.
MISALIGNMENT.--Figure 7-28 shows rapid
Rinse well with tap water.
and uneven tire wear caused by incorrect camber or
toe-in. The wheel alignment should be corrected to
Uneven Tread Wear
avoid further wear and mechanical problems.
If a tire shows signs of uneven or excessive tread
wear, the cause should be investigated and the
Figure 7-26.--Rapid tread wear caused by underinflation.
Figure 7-28.--Rapid tread wear caused by misalignment.