SERVICING OF CHEMICAL DE-ICING SYSTEMS:
It is essential for the correct operation of the ice protection system that servicing is carried out on a regular basis. The fluids used in these systems are based on:
Isopropyl alcohol is flammable and must therefore be treated with great care. Both the fluid types are prone to solidifying in to a jelly type substance if left on the blades the resulting deposits will build up and eventually obstruct the distribution nozzles and the overshoe grooves. This will lead to uneven distribution, or no distribution at all, of the de-icing fluids.
The commonly accepted method of keeping the de-icing pipes clear is to flush the system using methylated spirit and distilled water as follows. This is a general procedure and not specific to any aircraft type. Always refer to the aircraft AMM for the correct procedures.