Anti-Ice, Rain Flashcards
Explain the function of the WINDOW HEAT test switch
OVHT - simulates an overheat condition
PWR TEST - provides a confidence test to verify operation of the window heat system
Describe the function of the WINDOW HEAT switches
ON - window heat is applied to selected windows
OFF - window heat not in use
Explain which equipment is electrically heated with the PROBE heat switches ON
- associated PITOT PROBE(s)
- TEMP PROBE (TAT probe, not heated on the ground unless TAT test switch is pushed
- associated ALPHA VANE(s)
What ports are not heated
Static ports
Explain the AUTO function of the PROBE heat switches
In AUTO, probe heat is powered automatically when either engine is running
(We normally move these switches to ON after engine start and to AUTO during the shutdown checklist)
Explain the logic of the wing anti-ice L VALVE OPEN, R VALVE OPEN and the engine anti-ice COWL VALVE OPEN lights on the ovhd panel
Bright - related anti-ice valve is in transit, or anti-ice valve position disagrees with related ANTI-ICE switch position
Dim - related anti-ice valve is open (switch ON)
Extinguished - related anti-ice valve is closed (switch OFF)
Explain the meaning of an illuminated OVERHEAT indication on the window heat panel
- An overheat condition is detected
- OR electrical power to window(s) is interrupted
Explain the meaning of an illuminated probe heat light
The related probe is not heated
Describe the circumstances that would cause the illumination of a COWL ANTI-ICE light
Overpressure condition in duct downstream of engine cowl anti-ice valve
Describe the area of the engine that is heated when anti-ice is used
Engine cowl lip
Describe the indication when engine anti-ice is in use
TAI is displayed above N1 digital display
- TAI green: cowl anti-ice valve is open
- TAI amber: cowl anti-ice valve is not in position indicated by related engine anti-ice switch
Describe how setting takeoff power and lift-off affects the wing anti-ice system
- Left and right control valves close if either engine thrust is above takeoff warning setting or thermal switch is activated in either distribution duct. Switch remains ON
- Switch trips OFF at lift-off
