Ice protection - ELECTRICAL SYSTEM

want to read about : Ice protection - HOT AIR SYSTEM
ELECTRICAL SYSTEM

Fig. 13-5 Typical ice protection cyclic sequence

9. The  electrical  system  of  ice  protection  is generally used for turbo-propeller engine installa- tions, as this form of protection is necessary for the propellers.  The  surfaces  that  require  electrical heating are the air intake cowling of the engine, the  propeller blades and spinner and, when applicable,the oil cooler air intake cowling.
10. Electrical heating pads are bonded to the outer skin of the cowlings. They consist of strip conductors sandwiched between layers of neoprene, or glass cloth impregnated with epoxy resin.  To protect the pads against rain erosion, they are coated with a special, polyurethane-based paint. When the de- icing system is operating, some of the areas are con- tinuously heated to prevent an ice cap forming on the leading edges and also to limit the size of the ice that forms on the areas that are intermittently heated (fig.13-4).

Ice protection - HOT AIR SYSTEM

want to read about : Ice protection - INTRODUCTION
HOT AIR SYSTEM

Fig. 13-4 Electrical ice protection.

5. The hot air system provides surface heating of the engine and/or powerplant where ice is likely to form.  The  protection  of  rotor  blades  is  rarely necessary, because any ice accretions are dispersed by centrifugal action. If stators are fitted upstream of the first rotating compressor stage these may require protection. If the nose cone rotates it may not need anti-icing if its shape, construction and rotational characteristics  are  such  that  likely  icing  is acceptable.
6. The hot air for the anti-icing system is usually taken from the high pressure compressor stages. It is ducted through pressure regulating valves, to the parts requiring anti-icing. Spent air from the nose cowl anti-icing system may be exhausted into the compressor intake or vented overboard.

Ice protection - INTRODUCTION

INTRODUCTION

Ice protection

1. Icing of the engine and the leading edges of the intake duct can occur during flight through clouds containing  supercooled  water  droplets  or  during ground operation in freezing fog. Protection against ice formation may be required since icing of these regions can considerably restrict the airflow through the engine, causing a loss in performance and possible  malfunction  of  the  engine.  Additionally, damage may result from ice breaking away and being ingested into the engine or hitting the acoustic material lining the intake duct.

Fig. 13-1 Areas typically considered for ice protection.

2. An ice protection system must effectively prevent ice formation within the operational requirements of the particular aircraft. The system must be reliable, easy  to  maintain,  present  no  excessive  weight penalty  and  cause  no  serious  loss  in  engine performance when in operation.