Ice & Rain Protection Flashcards
What are the five subsystems of ice and rain protection?
Ice detection system
Wing anti ice
Engine anti-ice
Windshield and rain protection
Probe Anti-ice
When is the auto wing anti ice inhibited from?
1500agl - FL350
If radio altimeter is not valid, system utilizes FE+2000’ elevation MSL
How do the ice detectors detect ice?
They vibrate and clear air at a frequency range of approximately 40,000 Hz. Ice formation on the detective prepared changes its resonance frequency properties according to accumulation thickness.
Where do the ice detectors send their data to?
AMSC (Air management system controller) for operation of the WAI and data to the DCU (data compensator unit) for operation of engine anti ice
When is the crew advised to revert to manual operation of anti ice systems?
In the event of a single detector failure
What air does the WAI use to operate & heat the wings?
Intermediate Pressure (IP) or High Pressure (HP) engine bleed air depending on the engines power condition
Is there a way for only one engine to provide bleed air to the WAI?
Yes, thru a crossover duct
How is the crossover valve operated?
Fully automated, controlled by the air management system controller (AMSC)
How is the bleed air directed into the wings for WAI?
Via piccolo ducts on the leading edge of the wing.
What temperature does the wing anti ice over temp switch cause an annunciation on the primary EICAS?
175-185F
What does pressing the EVS heat switch do?
Manually turns on the EVS windows heat for 2 minutes.
What is the operation of the EVS window heat?
Turns on automatically with ice detected by the ice detectors.
Ice detected with landing gear up: EVS window heat will cycle on for one minute and off for seven minutes as long as ice is detected.
Ice detected with gear down: EVS heat will come on and remain on as long as ice is detected
What is the probe heat limitation in override on the ground?
No more than 30 seconds
