GM1 ADR.OPS.C.015(d) Maintenance of visual aids and electrical systems
ED Decision 2021/003/R
REMOVAL OF MARKINGS
A marking may need to be removed for various reasons (marking patterns are changed, physical areas or operating procedures are modified, or the thickness of the layers of paint becomes excessive, etc.)
It has been found that covering markings that need to be removed, with a darker colour (e.g. black or dark grey) in order to make them resemble the colour of the adjacent pavement (e.g. runway, apron, taxiway) is likely to mislead the flight crews, as well as drivers operating in this area because of the reflection of the sun or other sources of light upon the new surface. Moreover, the surface layer of paint will wear away or erode and the lower layers will become visible and this may cause confusion.
Methods used for removing unnecessary markings include but are not limited to water blasting, sand blasting, chemical removal, burning, etc.
If the sand blasting method is used, arrangements are necessary to remove the sand deposited on the pavement as the work progresses, in order to prevent accumulation.
Grinding is not recommended because of the damage to the pavement surface and probable reduction of the friction characteristics.
When chemicals are used for marking removal, a large and continuous source of water is usually needed to reduce potential damage to pavement surfaces and to dilute the chemicals washed into drains or channels. Prior to the use of chemicals, consideration is necessary to the applicable environmental protection requirements.
If burning is used to remove a marking, care is necessary not to damage the pavement surface, as a result of the extended periods of exposure to the heat source.
Examples of predetermined areas that should cover the area of the old marking(s), as well as adjacent markings, appear in Figure 1.
Figure 1