Ice and Rain Protection Systems Flashcards
what anti ice provided?
Wing leading edges
Engine intake cowls
Air data probes and sensors
Windshield and windows
what is used for anti icing? For wings and cowls?
14th stage bleed air
Where do electric anti icing provide?
Windshields, windows, air data probes, sensors
where are the controls and indications of anti ice?
Anti ice panel and wiper panel
What is the ice detection system?
Monitors and alerts pilots for icing
Where are the ice detector probes?
On each side of the airplane
When ice is detected what is generated?
Ice caution or ice advisory
When do we have ice caution message?
Icing conditions detected
Wing and cowl anti ice is selected off
When does the ice advisory message is generated?
Icing conditions detected
Wing and cowl anti is selected on
What do you see on EICAS when icinf conditions are no longer detected?
“ICE” caution and advisory
What is the purpose of 14th stage shutoff valves?
allows bleed air to pressurize the anti ice ducts for their respective side
How do you control the 14th stage shutoff valve?
On the bleed air panel
what is the purpose of wing and anti ice valve?
left and right and anti ice ducts. Controlled by the Wing Anti Ice System
What is the purpose of 14 stage isolation valve?
Allow both wings to be anti iced using one bleed source
How the wing and cowl anti icing valves are identified?
Color cyan and label CMD
What do the wing and cowl anti ice color and label indicate?
Commanded position. Not actual
What is at least required for 14th stage isolation valve?
One wing anti-ice valve
14th stage SOVs fail open, wing anti ice valves fail closed and the isolation valve fails in the last commanded position
What are the two modes that can be selected? for wing anti ice
Normal mode and standby mode
What is normal mode?
When wing anti ice required, normal mode is selected for valves to maintain a constant temperature
what is standby mode?
Used when directed by QRH
controls the wing anti ice valves to maintain a lower temperature across the leading edge than the normal mode
Where can you see wing-ice EICAS indications?
Primary, status and anti ice synoptic page
Wing Anti Ice primary page
Wing Inti Ice is selected: Amber gauges from 0-77.9%
What is the purpose of amber color on the arc?
For sufficient bleed air to the system: N2 should be 78% or greater
Wing Anti Ice status page
Appropriate advisory messages
What is thrust reverser override?
During a rejected takeoff or landing 14th stage bleed air is redirected to thrust reverser
Anti Ice will reactivate once trust verses are stowed
What is bleed air leak detection?
Single loop configuration with heat sensing loops detect air leak
Explain Cowl Anti Ice and Fail Open. Where do we turn them on?
14th bleed air
failed open to allow continuous air
What is the purpose of pressure relief valve?
If Cowl anti ice fails or 14th stage bleed air pressure increase, this valve prevents overpressure
do you have any message on EICAS? for overpressure valve
no only during external inspection
What are the modes of air data probes and sensors?
Ground and flight
For the air data probes and sensors what is the difference between ground and flight?
Ground mode; can be off, low heat or high heat
Flight mode all probes and sensors are heated regardless of switch position
What are the heated probes and sensors?
Left and right Pitot static probes
stand by Pitot probe
left and right AOA vanes
total air temperature probe
Explain windshield and window anti ice system
low heat level to prevent thermal shock
High heat level windshields are maintained at high heat while side windows remain at low heat
What is the maximum speed for wiper operation?
220
Question 3: How do ice detector probes operate?
Answer: Ice detector probes vibrate at high frequency.
Question 4: What action does the microprocessor take when the aircraft encounters icing conditions?
Answer: The microprocessor de-ices the probe electrically for 5 seconds during each sixty-second period.
Question 5: What role does the microprocessor play in the anti-icing system?
Answer: The microprocessor signals the data concentrator.
Question 6: How long does the microprocessor typically de-ice the probe for during each de-icing cycle in icing conditions?
Answer: 5 seconds.
Question 7: What is the frequency at which the microprocessor de-ices the probe during icing conditions?
Answer: Once every sixty-second period.
Question 7: What is the frequency at which the microprocessor de-ices the probe during icing conditions?
Answer: Once every sixty-second period.
Question 8: What is the purpose of vibrating the ice detector probes at high frequency?
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Answer: To prevent the formation of ice on the probes
Question 1: How are wing anti-icing valves normally positioned?
Answer 1: Wing anti-icing valves are spring-loaded to the closed position.
Question 2: What events can trigger the closure of wing anti-icing valves?
Answer 2: Loss of 14th-stage pressure or loss of electrical power causes the valve to close.
Question 3: How is the 14th-stage isolation valve operated?
Answer 3: The 14th-stage isolation valve is pneumatically operated.
Question 4: What controls the operation of the 14th-stage isolation valve?
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Answer 4: The 14th-stage isolation valve is electrically controlled
