Anti-Ice/Rain

Question 1

What are the components of the anti-ice and rain removal system?

Answer 1

Anti-Ice
–EAI
–WAI
–Window heat L1/R1 L2/R2
–Probe and sensor heat

Rain Removal
–Windshield wiper
–Hydrophobic coating on L1/R1

Question 2

What external probes, vanes, ports, antennas are electrically heated?

Answer 2

CAPT, FO, STANDBY PITOT
L/R ELEVATOR FEEL PITOT
L/R ALPHA VANES
TAT PROBE

Heated in AUTO if either engine operating, or manually selected ON

Question 3

Which flight deck windows are heated? When do ON/OVERHEAT illuminate/extinguish?

Answer 3

L1/R1 and L2/R2 are electrically heated

ON
-Power is supplied to window
-Extinguishes for
–Switch off
–System failure
–Window OVERHEAT (~62C)
–Window temp warm (~43C) (could be normal)

OVERHEAT
–Overheat for window (~62C), or
–Power interruption to window
–To reset, window must cool and re-cycle switch

Question 4

What does the Engine Anti-Ice system protect? How does it operate?

Answer 4

Engine cowl lip heated with bleed air
–From respective engine bleed upstream of bleed air valve

Electrically controlled, pressure actuated

Operate in icing conditions

Adjusts stall warning logic (SMYD)

EECs set approach idle

Question 5

What is the logic associated with the EAI switch ON?

Answer 5

Opens EAI valve allowing bleed air to heat cowl lip (irrespective of engine bleed air sw)

COWL VALVE OPEN (bright blue, then dim blue)

TAI (amber then green)

Adjusts stall warning logic (SMYD) while EAI switch on

EECs set approach idle

Question 6

What does an amber COWL ANTI-ICE light indicate?

Answer 6

Excessive pressure in duct leading to cowl lip

(Normally 50 PSI max, caution >65 PSI)

Question 7

What does a COWL VALVE OPEN light indicate? Dim/bright/extinguished?

Answer 7

EAI cowl valve position

Dim blue – valve open w/ switch ON
Bright blue – valve disagreement/in-transit
Extinguished – valve closed w/ switch OFF

Question 8

What does an amber/green TAI above the N1 gauge indicate?

Answer 8

Amber TAI – cowl valve fails to move to commanded position

Green TAI – cowl valve open with switch ON

Question 9

What does the Wing Anti-Ice system protect? How does it operate?

Answer 9

3 inboard leading edge slats heated by bleed air from respective duct downstream of bleed air valve, then exhausted overboard

WAI valve controlled by switch/AC motor

Adjusts stall warning logic for remainder of flight (SMYD)

Automatically close
–TLA advanced for takeoff, or
–Overheat on the ground

Question 10

What is the logic associated with the WAI switch position to ON? OFF?

Answer 10

ON
-Valves open (except autoclose on ground due overheat/takeoff)
-Stall warning adjusted for remainder of flight

OFF
-Valves close
-Stall warning remains adjusted for rest of flight

Question 11

How is WAI logic different on the ground vs in-flight?

Answer 11

In-Flight
-Stall warning adjusted for remainder of flight
-Overheat and TLA logic disabled

Ground
-Valves automatically close for overheat or TLA advanced for takeoff

Question 12

What does L/R VALVE OPEN for WAI indicate? Bright/dim/extinguished?

Answer 12

Dim blue - valves open with switch on

Bright blue - valve disagreement or in-transit

Extinguished - valves closed with switch off

Question 13

When is probe heat applied with switch in AUTO?

Answer 13

Either engine running

Question 14

What do CAPT PITOT, L/R ELEV PITOT, L/R ALPHA VANE, TEMP PROBE, and AUX PITOT caution lights indicate?

Answer 14

Electrical power not provided to respective sensor

Illuminate with fault/failure or switch AUTO and engines OFF

Lights inhibited if operating on STANDBY POWER