11.12 Ice And Rain Flashcards
How is electrical power supplied to propeller de ice boots?
Slip rings
Where does the heat for wing and engine anti ice system come from?
. Hot air of the engine bleed air system = Engine
. Pneumatic system = wing
What method is used to remove snow and ice prior to flight?
De icing following company procedures
What two systems do we have in place to solve rain visibility?
. Windshield wiper for each pilot
. A rain repellent system
What are the two main negative effects of ice build up?
. Aerodynamic quality of aircraft reduced
. Weight increases
What temperature does clear ice from at?
0 to -10 degree c
What temperature does rime ice form at?
Below -10 degrees c
Where does rime ice build up compared to clear ice?
Rime ice - immediately freeze on leading edge only
Clear ice - begins on leading edge and move onto aft surface
What three negative effects does ice build up cause?
. Decreas lift
. Increase in weight
. Increase in drag
How does the anti ice system heat the wing leading edge? (Thermal wing anti ice system)
Uses warn air from pnuematics to heat up wing leading edge
What 2 negative effects does ice have on engines?
. Disturbed air flow, can cause stall
. Pieces of ice can damage fan blades and inlet vanes
How does the aerofoil De icing rubber boots work?
. Uses de icing rubber boots at leading edges of wings and stab.
Rubber boots inflate, cracking the ice and ice gets blown away
When can thermal anti ice systems do their job?
When they are switched on before any ice builds up during flight
Where will you find thermal anti ice systems controls?
in line of sight in cockpit, overhead panel
How many rotary ice detectors will be on aircraft?
1 or 2
What does the rotary ice detector consist of in order to work?
A single phase AC motor
What happens when the electronic ice detector detects ice?
Generates a message to cockpit and can automatically activate the thermal anti ice systems
How does an electronic ice detector work?
Tip vibrates at a certain frequency, when ice builds up the probe becomes heavier and vibration reduces.
This gets noticed and activates heating unit ice melts and original frequency has returned. Then turned off
How do you prevent blockages in air data probes?
A probe heat system
How do you prevent ice on windshield?
An electrical heat system
How do you prevent frozen water lines?
A line and drain mast heat system
Where are the two thermal anti ice systems are installed in jet aircraft?
. The wing
. The engine
How does hot air get to the wing for anti icing?
Through small holes in the anti ice duct
When the wing leading edge has slats what type of anti ice ducts do we need to use?
Telescopic ducts
Where does the anti ice system get its air from?
Bleed air
How many switches does the wing anti ice system have?
1 as they need to be run at the same time to keep weight symmetry
Can wing anti ice operate on the ground?
No, only during flight
What type of valves are used in the engine and wing anti ice systems?
Solenoid controlled pressure valves
What type of function do all thermal anti ice valves have for safety a.
Manual override function
What is special about engine anti ice solenoid controlled valve?
It is fail safe to open when there is no electrical power
When will the fault light illuminate for a pressure regulating valve?
When you switch in wing anti ice button and the pressure doesn’t reach 14 psi
What is the purpose of the drain mast heat system?
Prevent freezing of the waste water outlets on the lower part of fuselage
How many different types of probes are there on an aircraft?
4
What are the 4 different types of probes on an aircraft?
. Temperature
. Pitot
. Static
. Angle of attack
What is another name for chemical anti ice holes in the wings and stabs?
Weeping wing systems
If using de ice boots on turbine engine aircraft where does the air come from?
Bleed air
Why are windows 1,2 and 3 heated?
1 = prevent ice
2 and 3 = prevent misting
By using rain repellent what is the contact angle between water and glass?
More than 80 degrees
How many different speeds does the windscreen wiper have?
2
When should you never switch on wipers?
Over 250 knots
When not wet
How long chemical anti ice for work?
1-2 hours
How many holes per inch TKS?
800
