Aircraft tire and wheel assemblies must operate under high pressures in order to carry the loads imposed on them. They should be treated with the same respect that any other high pressure vessel would be given. Following the recommended procedures given throughout this manual, as well as those provided by authorities such as wheel manufacturers, air-framers and industry regulatory agencies, will minimize the risks and probabilities of injury.

In the event of a conflict between recommended procedures, be sure to contact your Petlas representative before undertaking the procedure in question.


Follow the instructions given in the section on “General Mounting Instructions For Aircraft Tires”.

Be particularly attentive when:

  • Rolling tires on the floor and using mechanical lifting equipment to avoid possible back injuries.
  • Inspecting tires and wheels in advance for possible shipping damage.


  • When inflating tires, be sure to use a suitable inflation cage.
  • Keep pressure hose and fittings used for inflation in good condition.
  • Allow the tire to remain in the inflation cage for several minutes after reaching

    full inflation pressure.

  • Respect inflation pressures and all other safety instructions.


  • Careful attention should be shown to tire/wheel assemblies being handled or in storage.
  • Never approach a tire/wheel assembly mounted on an aircraft that has an obvious damage until that tire has cooled to ambient temperatures (allow at least 3 hours).
  • Always approach a tire/wheel assembly from an oblique angle, in the direction of the tire’s shoulder.
  • Deflate tires before removing them from the aircraft unless the tire/wheel assembly is to be immediately remounted on the aircraft, such as with brake inspections. Deflate tires before attempting to dismount the tire from the wheel or before disassembling any wheel component. Show caution when removing valve cores as they can be propelled at a high speed from the valve stem.
  • While serviceable tires may be shipped fully pressurized in the cargo area of an aircraft, Petlas’s preference is to reduce pressure to 25% of operating pressure or 3 bars / 40 psi, whichever is the lesser.
  • Remove from service tire/wheel assemblies found with one or more tie bolt nuts missing.



It causes because of damaged runway surface. Chevron cutting is just a visual condition and don’t have a negative effect the tire performance.

Remove from service if the chevron cutting results in chunking which extends to and exposes the reinforcing or protector ply. The area of the chevron cutting is more than the tread footprint or the chevron cutting extends below a tread rib.


Tires are designed to be tough, durable and to withstand large loads and high speeds. They can provide years of reliable service if a few precautions are followed.


Care should be shown when handling aircraft tires. While tough and durable, tires can be damaged or cut by sharp objects or if excessive force is used. Avoid lifting tires with conventional two prong forks of material handling trucks. Damage to bead mounting areas or the inner liner can occur. A wide, flat, pincher type fork assembly of the type that lifts the horizontal tire by squeezing against the tread surface is recommended. An alternate recommended method would be to use a rounded bar to lift the tire.


The ideal location for tire and tube storage is a cool, dry and reasonably dark location, free from air currents and dirt. While low temperatures (not below 0°C/32°F) are not objectionable, room temperatures above 32°C / 90° F are detrimental and should be avoided.

To aid in the control of ozone attack on rubber, the tire materials specialist adds waxes and protective chemicals. Some of these ingredients address ozone attack when the tire is in a static state at room temperature; other ingredients are activated by heat and protect the tire once it is in service. Wet or moist conditions have a deteriorating effect on tires and tubes, and can be even more damaging when the moisture contains foreign elements that are further harmful to rubber and cord fabric. 

Strong air currents should be avoided, since they increase the supply of oxygen and quite often carry ozone, both of which cause rapid aging of rubber. Particular care should be taken to store tires and tubes away from fluorescent lights, electric motors, battery chargers, electric welding equipment, electric generators and similar electrical devices, since they all create ozone. 


Make sure that tires do not come into contact with oil, gasoline, jet fuel, hydraulic fluids or other hydrocarbon solvents, since all of these are natural enemies of rubber and cause it to disintegrate rapidly. Be especially careful not to stand or lay tires on floors that are covered with oil or grease. When working on engines or landing gears, tires should be covered so that oil does not drip on them.

If tires accidentally become contaminated, wash them off with denatured alcohol and then with a soap and water solution. After cleaning, be sure to remove any water that may have accumulated in the interior of an unmounted tire. If after cleaning, the surface of the tire appears soft, or spongy, or bulges are present, the tire is not suitable for service.


The storage room should be dark, or at least free from direct sunlight. Windows should be darkened with a coat of blue paint or covered with black plastic. Either of these will provide some diffused lighting during the daytime. Black plastic is preferred since it will lower the temperature in the room during the warm months and permit tires to be stored closer to the window.

Fluorescent or mercury vapor lights should not be used because they generate ozone. Low intensity sodium vapor lights are recommended. See the section on “Aircraft Tires and Ozone” for more information.


Whenever possible, tires should be stored in regular tire racks which hold them up vertically. The surface of the tire rack on which the weight of the tire rests should be flat and, if possible, 3 to 4 inches wide to prevent permanent distortion of the tire.

Axial (circumferential) rotation of unmounted, vertically stored tires should not be required. With respect to the effect of storage time on rotation, we strongly suggest the use of first-in first-out (FIFO) storage. This helps to avoid overage, distortion and related field issues.

If tires are stacked horizontally, they may become distorted, resulting in mounting problems. This is particularly true of tubeless tires. Those on the bottom of a stack may have the beads pressed so closely together that bead spreader tools will have to be used to properly space the beads for contact with the wheel during initial inflation.

Tires which are stacked on top of each other, sidewall-to-sidewall, have increased stresses in the tread grooves. If tires are stored for an extended period of time, or in an environment with high ozone concentration, ozone cracking is most likely to form in the tread grooves. If tires must be stacked, they should not be stacked for more than 6 months maximum. The maximum stacking height:

-    3 tires high if tire diameter is greater than 40 inches / 1 meter.

-    4 tires high if tire diameter is less than 40 inches inches / 1 meter.

Tubes should be stored in their original cartons whenever possible. If stored without their cartons, they should be lightly lubricated with talc powder and wrapped in heavy paper.

Tubes can also be stored in matching tires. Tires should be clean and lightly lubricated with talc with tubes inflated just enough to round them out.

Under no circumstances should tubes be hung over nails, pegs or any object that might form a crease in the tube. Such a crease will eventually produce a crack in the rubber.

Once a tire has been properly mounted and the assembly verified for pressure retention, only minimal precautions need be taken 

-    Do not expose the tire toexcessively high temperatures (greater than 40° / 104° F)

-    Do not expose the tire to direct sunlight or to high ozone concentration

-    Avoid contact with contaminants (oil, grease, etc.)

-    A Mounted tire / wheel assembly properly prepared and delivered to a line maintenance station as an airworthy replacement unit should meet the following storage conditions: 

-    To minimize the effects of ozone attack and where reinflation capability exists, tire pressure may be reduced to a value below operational pressure, but not less than 25% of the operational pressure or 40 psi / 3 bars, whichever is less.

-      Transportation of a serviceable aircraft tire/wheel assembly should be in accordance with the applicable regulatory body for the airline. While serviceable tires may be shipped fully pressurized in the cargo area of an aircraft, Petlas’s recommendation is to reduce pressure to 25% of operating pressure or 3 bars / ~40 psi, whichever is the lesser. Reinflate to operating pressure before mounting on the aircraft.