GM1 41 (c) Specially prepared winter runway

‘Frozen sand’ is a method to improve the surface friction characteristics of an ice-covered surface by sand or grit fixed to the surface through a melting/freezing process. Frozen sand can be achieved using several techniques. One example is pre-wetting the material with hot water just prior to application in order to have the hot sand melting the top layer of the ice, which then immediately refreezes to fix the material to the surface. Another technique is to pre-wet the material with a suitable chemical in order to achieve a similar effect.