11.12 Flashcards
What are the definitions of clear, rime and mixed ice?
Clear ice - formed by larger super cooled water droplets freezing after coating the surface making a hard glossy transparent covering of ice
Rime Ice - small droplets, white appearance irregular easier to remove
Mixed ice - combination with a mushroom texture
What are the effects of ice during flight?
-aero foil ice hinders lift and increases drag
-vibration, incorrect instrument reading
-engine performance hindered
-imbalance loss of control
What are the visual detection methods for ice?
-in flight visual detection by pilot
-wing inspection lights show the wing at night
-visual ice detection = small posts or detector heads mounted between windshields ice collects on them
Hot rod detector function?
Outside the cockpit window ice builds on the leading edge of the probe it can be de iced to see if the condition has persisted
What is the function of the pressure operated ice detector?
A hollow tube with holes drilled in the leading edge and trailing edge
In normal flight a pressure difference is created when blocked by ice which is sensed
Automatically anti icing occurs including on the probe to sense if the condition persists
How does a rotary ice detector function?
-the rotary shaft runs around driven by an Ac motor
-their is a sharp edge that runs along the shaft and will scrape off any ice build up which is detected
-the system self resets through the scraping
How does the vibrating ice probe detector function?
-The resonant frequency changes with ice build up which can be detected
-it self resets with heat
Which detectors sense icing condition rather than ice itself?
-moisture detector controller
-moisture sensing head
-thermal switch
What is anti icing?
The preventing of ice build up
What is thermal pneumatic anti icing?
Warm air enters a piccolo tube which travels lengthwise along the leading edge and exits through holes allowing circulation
What must be done to leading edge slats for anti icing?
Instead have a pneumatic system in the slats instead of the leading edge
If electrical power is lost what happens to the anti ice valve?
They close
When is engine anti ice activated?
Before or when wing anti ice is on
How are windshields anti iced?
Electronic heating
What is chemical anti icing and where is it used?
(Weeping wings)
Chemical anti ice prevents ice through being pumped through a mesh onto the iced surfaces
