Ice and Rain Control Systems Flashcards
Describe the operating principle of inflatable deicer boots.
Deicer boots are constructed of durable rubber material and are attached to the leading edge of aircraft wings and stabilizers. When inflated, the boots will expand and crack ice that has built up on top of them, allowing the ice to break off and be carried away by the air stream.
What are two methods of inflating pneumatic deicer boots?
Bleed air from the turbine engine compressor, or from an engine-driven air pump.
What methods are used to attach deicer boots to the leaning edges of wing and tail surfaces?
Bonded to the surfaces with cement, fairing strips, screws, or a combination.
What it the purpose of an air-oil separator in a pneumatic deicing system?
The purpose is to prevent deterioration of the rubber boots caused by contact with oil.
What is used to clean deicer boots?
Soap and water.
What must be done before you can make a cold patch repair to a deicer boot?
The boot must be relieved of its installed tension before applying the patch.
What component of a pneumatic deicer system normally allows suction to be allied to the boots to hold them down in flight?
Solenoid distributor valve.
Describe the operating principle of thermal anti-icing systems?
Anti-icing system prevent the build up of ice. Thermal anti-icing uses hot air in cycles to prevent this build up. The hot air is forced between two skins and is supplied for as long as the anti-icing system is turned on.
What methods are used to supply heated air for thermal anti-icing systems?
Bleed air, engine exhaust heat exchanges, and ram air heated by a combustion heater.
How is overheating prevented in a thermal anti-icing system using bleed air?
Use of thermal switch that will actuate a shut-off valve if the temperature of the leading edge exceeds 185 degrees F. Once the temperature drops, the valve is re-opened.
In a thermal anti-icing system, what happens to the air after it has heated the leading edge of the wing?
The air is dumped to the atmosphere at locations where ice formation could be critical.
What problems are associated with electricity heated windshields?
Delamination, arcing, scratches and discoloration.
What is windshield delamination?
Separation of the plies.
What does arcing usually indicate in an electrical heated windshield?
A breakdown of the conductive coating.
What type of power is used to operate windshield wiper systems?
Electrical or hydraulic power.
