Anti-Ice and Rain Flashcards
With anti-ice switches in AUTO, what determines icing conditions?
2 icing condition detectors located on each side of the lower forward fuselage measure liquid water content
They are inhibited on the ground below 75 kts
Are the icing detectors heated?
Yes, after engine start.
Types of engine anti-ice?
Engine core and cowl inlet protection
ICING ENG EICAS message?
Message and aural warning will sound of ice is detected and the ENGINE ANTI-ICE selector is OFF
Green EAI indication?
Displayed above the N1 indication when an engine anti-ice valve is open
Engine anti-ice duct leak?
Each engine has an anti-ice duct leak detection system. If leak is detected, the respective engine anti-ice valves will close
Wing Anti-Ice?
How is it powered?
Locations?
Shedding?
Inhibited when?
An electric system powering thermal mats on 4 mid-wing slats on each wing. Slats 2-5 and 8-11
Each slat has three mats.
Wing anti-ice may be shed during high electrical loads (such as flap retraction) for as much as 30 seconds
Inhibited on the ground below 75 knots
What protection is there against assymetrical wing icing
If one mat fails on a wing, the corresponding mat on the opposite wing depowers
What is the logic for the wing anti-ice in AUTO?
What is meant by “clean up cycle?”
In flight, with the WING ANTI-ICE selector in AUTO, system is powered on and off by the ice protection system. Available in flight and above 75 kts on the ground.
After icing is no longer present, the system may enter a clean up mode. In the cleanup mode, the system continues to provide electrical power to the mats to clear any residual ice.
WING ANTI-ICE selector in ON position?
Wing anti-ice will remain powered inflight as long as TAT is below 25 degrees C
What is the anti-ice stick shaker logic?
When does stick shaker return to normal?
If flaps not up, either engine or wing anti-ice increases the stick shaker and minimum maneuvering speeds.
Stick shaker returns to normal when no icing conditions have been detected for a certain time and TAT is greater than 10 degrees C, or when aircraft lands
How does the pack inlet anti-ice system function?
Pack inlets have electric heaters on the leading edge of each inlet.
Functions automatically with signals from the automatic ice detection system.
The anti-ice functions are inhibited on the ground and when the TAT is above 10 degrees
How are flight deck windows heated?
Forward windows have exterior surface anti-icing protection and interior surface anti-fogging.
The side windows have interior surface anti-fogging protection only.
What does INOP mean on the PRIMARY window heat switches?
Switch is not selected ON
Overheat is detected
System fault has occurred
What are the BACKUP WINDOW HEAR switches for?
Backup anti-fogging system for the FWD windows.
Commanded on when the BACKUP L FWD and BACKUP R FWD switches are ON and the primary window hear system has failed
When are probes heated?
3 pitot probes and 2 AOA vanes are heated when either engine is running
The TAT probe is heated in flight
ENGINE ANTI-ICE switch in AUTO:
If icing conditions are detected,
the engine anti-ice valves will open and bleed air is supplied to the engine core and inlet cowl
when ice is no longer detected, the engine anti-ice valves close
automatic operation of the engine anti-ice system is inhibited on the ground
ENGINE ANTI-ICE during ground operations?
ENGINE ANTI-ICE must be in ON position for ground operations, when OAT is 10 degrees or less and icing conditions exist
EEC role in engine anti-icing?
In addition to bleed air protection, the EEC automatically adjusts engine idle speed to prevent engine icing and helps mitigate adverse effects when ice crystal conditions persist
Inflight ENGINE ANTI-ICE procedures?
Must in AUTO or ON when
TAT is 10 degrees or less and icing conditions exist,
except during climb, cruise and descent when OAT is blow -40 degrees C
When do engine anti-ice valves close automatically?
During engine start
Bleed air over temperature
Bleed air over pressure
Bleed air leak detected
Engine fire handle is pulled
WING ANTI-ICE switch in AUTO?
Inflight, power is supplied when icing conditions are detected
When icing conditions are no longer present, the system may enter clean up mode, and WAI will remain on EICAS until this cycle is complete
