Term
| What prevents overheating of the wing leading edge skin in a thermal anti-ice system that is operated by engine bleed air? |
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Definition
| A thermal switch will cause a valve to close and shut off the flow of bleed air when the temperature of the skin reaches a predetermined value |
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Term
| What methods are used to supply heat for thermal anti-icing systems? |
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Definition
| Turbine compressor bleed air, engine exhaust heat exchangers and ram air heated by a combustion heater |
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Term
| What must be accomplished to a deicer boot prior to a cold patch repair? |
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Definition
| Relieve the installed tension |
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Term
| How are deicer boots attached to leading edges of wing and tail surfaces? |
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Definition
| Fairing strips and screws or cemented |
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Term
| What are two methods of inflating pneumatic deicer boots? |
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Definition
Engine-driven vacuum pump and turbine compressor bleed air |
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Term
| What is the function of the air/oil separator used in some deicer boot systems? |
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Definition
| It is used to remove oil from the pressurized air in a wet-type vacuum pump system |
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Term
| What normally keeps deicer boots held down in flight? |
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Definition
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Term
| How is the temperature maintained in a thermal anti-icing system? |
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Definition
| By mixing bleed air and ambient air |
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Term
| What is the purpose of the electronic timer in a pneumatic deicer boot system? |
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Definition
| It controls the operating sequence and time intervals |
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Term
| How does a pneumatic rain removal system work? |
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Definition
| The air blast forms a barrier that prevents raindrops from striking the windshield's surface |
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Term
| Why is a windshield rain repellent system not operated when the windshield is dry? |
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Definition
| Heavy undiluted repellent will restrict window visibility |
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Term
| What methods are used to remove rain from a windshields? |
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Definition
| A chemical rain repellent, wiping or blowing off |
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Term
| What are the two inherent problems associated with windshield wipers, when operated in flight? |
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Definition
| Aerodynamic forces reduce blade pressure and failure to achieve fast enough wiper oscillations |
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Term
| What are the effects of electric windshield arcing? |
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Definition
| Local overheating and damage of windshield |
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Term
| What are several problems associated with electrically-heated windshields? |
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Definition
Delamination, discoloration, scratches and arcing
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Term
| What happens to the thermal anti-icing airflow after it has heated a leading edge surface? |
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Definition
| The airflow is exhausted to the atmosphere |
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Term
| Why are anti-icing systems using turbine-engine bleed air provided with an overheat system? |
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Definition
| To prevent aircraft structure damage |
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Term
| When is windshield delamination acceptable? |
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Definition
| When within limits established by manufacturer and it is not in an area where it affects the optical qualities of the windshield panel |
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Term
| How can an electrically-heated pitot tube with an ammeter installed in the system be checked for operation? |
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Definition
| Verified by noting the current consumption when the heater is turned on |
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Term
| What powers windshield wiper systems? |
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Definition
| Electrical or hydraulic power |
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