Whenever an aircraft touches down the runway, the rotation of the landing gear wheels starts and as a result, the friction forces make some rubber peel off the wheels. Until the wheel rotation process matches the aircraft speed, this process keeps going on in a continuous manner.

That’s why the touchdown zone is prone to rubber deposits or accumulation with its unavoidable adverse effects like –

• Obliterating the runway markings thereby confusing the pilots and generating an area of danger
• Becoming slippery upon getting wet in rainy times thereby contributing towards runway excursion

Popular methods of removing the rubber deposits off the runway

Water blast – High pressure water blasting is one of the mechanical methods used for the removal of rubber deposits. The equipment involved in the process can vary from a manually operated nozzle or single operated nozzle having supply by pump & water tender to self-propelled semi-trailers that incorporate a pump within. Moreover, a water tank and a high-pressure water spray bar can be also used. Although this method proves to be reasonably effective especially on the lightly contaminated areas however its effectiveness gets compromised as the depth of the contamination increases.

Chemical solvent – Spraying of the solvent solution on the contaminated area is primarily performed in this process. Upon spraying, a specified time period is allowed for waiting and then after, washing and sweeping is done. Depending on the surface, different chemical agents are used and due to the aggressive nature of the cleaning compound, sufficient care should be taken not only during the application of the chemical but after as well. Another key consideration of applying the chemical is that if the chemical is allowed to remain on the surface for too long, the pavement surface and paint can be damaged, therefore when washing the cleaning compound off the pavement surface, proper dilution of the chemical should be done so that it doesn’t harm any associated drainage system, vegetation and wildlife along with the nearby streams.

Hot compressed air – This technique makes use of high temperature gases for burning the rubber deposits or rubber accumulation. For this, an air-gas mixture is fed into a combustion chamber in which the burning takes place. Scientifically, the resulting exhaust emits from orifices directly onto the surface at high temperatures thereby softening and shearing off the rubber particles which can be brushed from the surface using a brush machine that most of the airports possess.In comparison to other methods, there is little danger of the surfacing material becoming loose with hot compressed air further preventing any foreign object ingestion but regular monitoring should be done when it for asphaltic concrete runways.

Removal of rubber from runway is very essential for the planes to avoid skidding specially during rains. When rubber is removed from a runway it is about restoring the friction and not about removing the black screeching marks