Tire Inspection Off of the Aircraft Tire Repair and Retreading The technician should follow airframe and tire manufacturer  instructions to determine if a tire is repairable. Many example  guidelines have also been given in this section. Nearly all  tire repairs must be made at a certified tire repair facility  equipped to perform the approved repair. Bead damage, ply  separation, and sidewall cord exposure all require that the  When inspecting a tire removed from the aircraft, pay special  attention to the bead area since it must provide an air tight  seal to the wheel rim and transfer forces from the tire to the  rim. Inspect the bead area closely as it is where the heat is  concentrated during tire operation. Surface damage to the  chafer is acceptable and can be repaired when the tire is  retreaded. Other damage in the bead area is usually cause  for rejection. Damage to the turn-ups, ply separation at the  bead, or a kinked bead are examples of bead area damage  that warrant the tire be discarded. The bead area of the tire  may sustain damage or have an altered appearance or texture  on a tire that has been overheated. Consult a certified tire  repair station or re-tread facility when in doubt about the  condition observed. The wheel rim must also be inspected  Damaged or suspected damaged areas of the tire should be  re-inspected while the tire is off the aircraft. Cuts can be  probed to check for depth and extent of damage below the  tread. In general, damage that does not exceed 40 percent  of the tire plies can be repaired when the tire is retreaded.  Small punctures with a diameter on the tire inner surface  of less than  1 ⁄ 8-inch and a diameter on the outer surface  of less than ¼-inch can also be repaired and retreaded. A  bulge caused by ply separation is reason to discard a tire.  However, a bulge caused by tread separation from the tire  carcass may be repairable during retread. Exposed sidewall  cord or sidewall cord damage is unacceptable, and the tire  cannot be repaired or retreaded. Consult the tire manufacturer  or certified retreader for clarification on damage to a tire. Once a tire has been removed from the wheel rim, it should  be inspected for condition. It may be possible to retread the  tire at an approved repair station and return it to service. A  sequential inspection procedure helps ensure no parts of the  tire are overlooked. Mark and record the extent of all damage.  Advisory Circular (AC) 43-13-1 gives general guidelines  for tire inspection and repair. Tires must only be repaired  by those with the experience and equipment to do so. Most  tire repairs are accomplished at a certified tire repair facility.  free, the wheel halves may be disassembled.  [Figure 13-150] Radial tires have only one bead bundle on each side of the  tire. The sidewall is more flexible in this area than a bias ply  tire. The proper tooling should be used, and pressure should  be applied slowly to avoid heavy distortion of the sidewall.  Lubrication may be applied and allowed to soak into the tire- wheel interface. Only soapy tire solutions should be used.  Never apply a hydrocarbon-based lubricant to an aircraft tire  as this contaminates the rubber compound used to construct  the tire. Beads on tube-type and tubeless tires are broken free  in a similar manner. for damage. An effective seal without slippage, especially  on tubeless tires, is dependent on the condition and integrity  of the wheel in the bead seat area.  Overheating of a tire weakens it even though the damage  might not be obvious. Any time a tire is involved in an aborted  takeoff, severe braking, or the thermal plug in the wheel has  melted to deflate the tire before explosion, the tire must be  removed. On a dual installation, both tires must be removed.  Even if only one tire shows obvious damage or deflates, the  loads experienced by the mate are excessive. Internal damage  such as ply separation, is likely. The history of having been  through an overheat event is all that is required for the tire  to be discarded. 13-87 Figure 13-150.  An electrohydraulic tire bead breaker (left) used on large tires and a manual tire bead breaker (right) used on small tires.