Aircraft Tire UV and Ozone Protection | Compounds and Additives Explained
Aircraft tires are exposed to intense ultraviolet (UV) radiation, atmospheric ozone, temperature extremes, and long periods of static loading on airport ramps. Without specialized rubber compounds and protective additives, these environmental factors would cause premature cracking, surface degradation, and loss of structural integrity.
To meet aviation safety and durability requirements, aircraft tire manufacturers use carefully engineered materials designed to prevent UV light damage and ozone-induced rubber degradation.
Why UV Light and Ozone Degrade Aircraft Tires
UV radiation breaks down rubber polymers at the surface of aircraft tires, leading to embrittlement, surface checking, and reduced elasticity. Ozone—commonly produced by electric motors, ground power units, and airport infrastructure—attacks rubber under tension, causing characteristic sidewall cracking.
Because aircraft tires often remain under load while parked, long-term ozone resistance and UV protection are critical for maintaining airworthiness and extending tire service life.
Antioxidants Used in Aircraft Tire Compounds
Antioxidants are essential additives in aircraft tire rubber formulations. They slow oxidative aging caused by heat, oxygen, and ultraviolet exposure.
Common antioxidant systems include:
- Phenolic antioxidants that improve long-term thermal and oxidative stability
- Amine-based antioxidants that enhance resistance to heat aging and fatigue under cyclic loading
These antioxidants help preserve flexibility, tensile strength, and crack-resistance throughout the tire’s operational life.
Antiozonants That Prevent Ozone Cracking
To protect against ozone cracking, aircraft tire manufacturers rely on p-phenylenediamine (PPD) antiozonants, including compounds such as 6PPD and DPPD.
These antiozonants migrate to the tire surface and react with ozone before it can damage the rubber. This sacrificial protection system is especially important for aircraft tire sidewalls, which experience continuous flexing and tensile stress.
Wax-based antiozonant systems
Aircraft tires also contain carefully engineered blends of microcrystalline and paraffinic waxes. These waxes migrate to the surface over time, forming a thin protective film that acts as a physical barrier against ozone and oxygen during static storage.
Carbon Black as a UV Stabilizer in Aircraft Tires
Carbon black is the primary UV-blocking additive used in aircraft tire construction. In addition to reinforcing the rubber mechanically, carbon black absorbs ultraviolet radiation and converts it into harmless heat.
This protection prevents UV penetration into the rubber compound and is the primary reason aircraft tires are manufactured with black sidewalls and tread surfaces.
UV Stabilizers and Light-Protection Additives
While carbon black provides most UV protection, some aircraft tire compounds may also include supplemental UV stabilizers in specialized layers. These can include limited use of light stabilizers or UV absorbers where long-term surface stability is required.
Such additives are used selectively to avoid compromising the tire’s dynamic fatigue performance.
Rubber Polymers and Inherent Environmental Resistance
Environmental resistance is also influenced by the base rubber polymers used in aircraft tire construction:
- Natural rubber for carcass plies, offering excellent fatigue resistance with added ozone protection
- Butadiene rubber blends in tread compounds for improved crack resistance and wear performance
- Butyl and halobutyl rubbers in inner liners for superior ozone resistance and air retention
Each polymer is chosen to balance mechanical performance with environmental durability.
External Protection and Aircraft Tire Maintenance
In some storage or maintenance scenarios, approved external anti-ozone or UV-protective coatings may be applied to aircraft tires. These products supplement the tire’s built-in protection and are typically governed by aircraft maintenance manuals and regulatory guidance.
How Aircraft Tire Manufacturers Achieve Long-Term Durability
Aircraft tire resistance to UV light and ozone degradation is achieved through a multi-layered materials strategy rather than a single additive. By combining antioxidants, antiozonants, wax systems, reinforcing fillers, and polymer selection, manufacturers ensure reliable performance in harsh aviation environments.
This engineered approach allows aircraft tires to maintain safety margins, flexibility, and structural integrity throughout extended service and storage cycles.