Tyre maintenance costs will be at their lowest and tyre life will be at its longest if proper maintenance practices are followed. Safe tyre operation also depends on proper maintenance. Therefore preventive tyre maintenance leads to safer and more economical operations.
Tyre Preventive Maintenance
Aircraft tyres are under severe strain during takeoff and landing. Under normal conditions, with proper control and maintenance of the tyres, they are able to withstand these stresses and perform as designed.
Loaded tyres that are left stationary for long time can develop temporary flat spots. If possible, an aircraft parked for long periods 30 days or more should be jacked up to remove weight from the tyres.
Tyres that have been subjected to unusually high service braking or operating conditions such as REJECTED TAKEOFFS or OVERSPEED LANDINGS (Overspeed landings are those that exceed the tyre speed rating) should be removed and scrapped. Even though visual inspection may not show apparent damage but tyres may have sustained internal structural damage.
Crosscut runway surfaces drain water rapidly but increases the tyre wear. Tyre failure upon landing can have several causes. Landing with the brakes on is one of them. This is mitigated on aircraft with anti-skid systems but can occur on other aircraft. Other errors in judgment, such as landing too far down the runway and having to apply the brakes heavily, can cause overheating or skidding. This can lead to flat-spotting the tyres or blow out.
Tyres that have deflated due to FUSE PLUG RELEASE should be removed from aircraft and scrapped. If this has been occurred in rolling conditions, the mate tyres have been subjected to high stress conditions and should also be removed from service. If this has occurred in a static (not rolling) condition, the mate tyre does not have to be removed unless it fails to pass other Aircraft Maintenance Manual (AMM) or applicable Component Maintenance Manual (CMM) service or inspection criteria.
For HARD LANDINGS, AMM should be followed. Also all wheels should be checked in accordance with the applicable wheel maintenance manual or aircraft maintenance manual.
Tyres should be kept clean and free from contaminants such as oil, grease, hydraulic fluids, tar, and degreasing agents which have a deteriorating effect on rubber. Contaminants should be wiped off with denatured alcohol, then tyre should be washed immediately with soap and water and inspected for surface damage such as softening or blistering.
Keep airport runway and taxiway surfaces clean from FOD. Cleaning of runway and taxiway is the responsibility of the Airport Authority.
Ramps and hangar floors should be kept free of all foreign objects that may cause tyre damage. This requires continuous diligence on the part of all aviation personnel. Do not ignore foreign object damage (FOD). When discovered, action must be taken to remove it. While FOD to engines and propellers gains significant attention, much damage to tyres is avoidable if ramp areas and hangar floors are kept clean.
Further Read: Tips for Aircraft Tyres Maintenance
Tyre damage on takeoff is often the result of running over some foreign object. Thorough preflight inspection of the tyres and wheels, as well as maintenance of hangar and ramp surfaces free of foreign objects, are keys to prevention of takeoff tyre failure. A flat spot caused on the way to the runway may lead to tyre failure during takeoff.
Tyres dissipate some static electricity in service but this conductivity will change with the cleanliness of the tyre surface, atmospheric conditions and runway surface.
Now you might be thinking how tyres can pass electricity? But let me clear your doubt, Yes as per latest tyre development they can pass electricity.
Are Aircraft Tyres Conductive?
Yes, Today’s tyres are conductive. In early days when tyres were not sufficiently conductive, aircraft used to have a conductive strip hanging down from the axle of the landing gear. Upon landing, this strip would be the first part of the aircraft to touch earth. This discharges any static electricity accumulated on the outer surfaces of the aircraft. Now you don’t see them any more.