Ice And Rain Control Systems Flashcards
What methods are used to supply heat for thermal anti-icing systems?
Turbine compressor hot air, engine exhaust heat exchangers and ram air heated by a combustion heater.
How is the temperature maintained in a termal anti-icing system?
By mixing heated air with ambiente air.
What happens to the termal anti-icing airflow after it has heated a leading edge surface?
The airflow is exhausted to the atmosphere.
How can an electrically heated pitot tube with an ammeter installed in the system be checked for operation?
It can be verified by noting the current consumption when the heater is turned on.
What are two methods of inflating pneumatic deicer boots?
An engine-driven vacum pump and bleed air from a turbine-engine compressor.
What normally keeps deicer boots held down in flight?
Suction is supplied to the boots during flight.
What is the function of the oil separator used in some deicer boot systems?
Remove oil before it reaches the boots damaging the rubber.
How are deicer boots attached to the leading edges of wing and tail surfaces?
Bonding, fairing strips and screws, or a combination of both.
What must be accomplished to a deicer boot prior to a cold patch repair?
Relieve the installed tension.
What is the purpose of the electronic timer in a pneumatic deicer boot system?
It controls the operating sequence and time intervals.
Why is a windshield rain repelent system not operated when the windshield is dry?
Reduces visbility and its hard to remove when dry.
Name at least two methods used to remove rain from a windshield:
Whipers, pneumatic blast, chemical rain repeler, hydrophobic seal coating
What powers windshield wiper systems?
Electrical or hydraulic Power.
What are the two inherent problems associated with windshield wipers, when operated in flight?
(1) Aerodynamic forces reduce blade pressure (2) Failure to achieve fast enough wiper operations.
How does a pneumatic rain removal system work?
The air blast breaks the rains drops into small particles that are then blow away.
What prevents overheating of the leading edges of a thermal anti-ice system operated by engine bleed air?
Overheat sensors signal the anti-icing valves to close and shunt off the hot air.
Why is it necessary to provide overheat protection for anti-icing systems that use turbine engine bleed air?
The air is too hot and can damage the aircraft estruture.
What are the effects of arcing on an electrically heated windshield?
Localized overheating and damage to the windshield.
Describe several potential problems associated with electrically heated windshields:
Arcing, delamination, scratches and discolorations.
What important step should be taken prior to making a cold-patch repair to a deicer boot?
Consult the manufacturer’s service manual.
Where would you find information on the acceptable limits of windshield delamination?
In the reference material provided by the manufacturer.
