What controls the temperature in a thermal anti-icing system?
Hot and cold air are mixed
What are the sources of heat for thermal anti-icing systems?
Bleed air from the compressor section of a turbine engine,
engine exhaust heat exchangers,
and combustion heaters
What prevents overheating of the leading edges of a thermal anti-ice system operated by engine bleed air?
Overheat sensors close anti-icing valves and shut off the hot air
What happens to the hot air used by a thermal anti-ice system after it has heated the surface?
The air is dumped (exhausted) overboard
Why is it necessary to provide overheat protection for anti-icing systems that use turbine engine bleed air?
The air is hot enough to cause damage to the aircraft structure
What are the effects of arcing on an electrically heated windshield?
Localized overheating and damage to the windshield
Can the operation of an electrically heated pitot-tube be checked with the aircraft's ammeter, and if so, how?
Yes, turn on the pitot heater and watch the deflection of the ammeter needle
Describe several potential problems associated with electrically heated windshields
Arcing, delamination, scratches, discoloration
Why do some pneumatic deicer boot systems have and electrically operated timer?
To automatically cycle the boots, provide the proper rest time, then recycle the boots
What are the two common methods of inflating deicer boots?
Bleed air from a turbine engine, and
exhaust from an engine driven vacuum pump
What procedure is used to hold deicer boots flat with the airfoil surface during flight?
Suction is applied to the boots
Why do some deicer boot systems incorporate an oil separator?
If a wet pump system is used, the oil must be removed before it reaches the boots because it would damage the rubber
What methods are used to attach a deicer boot to the leading edges of the wing and tail surfaces?
fairing strips and screws, or
What important step should be taken prior to making a cold-patch repair to a deicer boot?
Consult the service manual and follow instructions
Describe the methods commonly used to remove rain from a windshield
a blast of air, or
chemical rain repellant
What power sources are used to operate windshield wipers?
Electric or Hydraulic
Name two problems associated with in-flight operation of aircraft windshield wipers
Insufficient blade pressure caused by aerodynamic forces and
failure to oscillate fast enough
Describe the operation of a pneumatic rain removal system
A high velocity air blast prevents the rain from reaching the windshield
What are the effects of spraying rain repellant on a dry windshield?
It smears and streaks, reducing visibility, and is hard to remove when dry
Where would you find information on the acceptable limits of windshield delamination?
In reference material provided by the manufacturer