ANTI ICE/ RAIN

Question 1

What are the components of the rain removal system on the 737-800?

Answer 1

Windshield wipers and hydrophobic rain repellent coating on #1 windows

Question 2

Which external probes, vanes, ports, antennas, etc. are electrically heated?

Answer 2

Anything that sticks out and has a light on the overhead Heated anytime engine(s) are running (dark unless malfunction):
CAPT/FO PITOT
L/R ELEV PITOT
L/R ALPHA VANE
TEMP PROBE
AUX PITOT
We turn switch ON after start to match the condition (even though they’re already hot - we cannot turn them off)`

Question 3

Which Flight Deck windows are heated?

Answer 3

1 and #2 (both sides)

Question 4

Windshield. What causes the ON (green) lights and OVERHEAT (amber) lights to illuminate and extinguish?

Answer 4

ON = power is being applied to the respective window. The light will extinguish if:

• Overheat condition = OVERHEAT + MC/ANTI-ICE
• Switch turned OFF
• Failure in system

Question 5

OVERHEAT =. {windshield)

Answer 5

overheat condition for respective window (power is removed automatically and cannot be reset until cooled) OR electrical power has been interrupted.
The light will extinguish if overheat or power condition is corrected (if power is removed, you must recycle switch to get power back)

Question 6

What does the Engine Anti-Ice System protect from icing?

Answer 6

The engine cowl lip.

Question 7

How is heat provided for engine anti-ice?

Answer 7

5th and 9th stage bleed air off the respective engine. *if you close an engine bleed air valve you will still have anti-ice

Question 8

How does the engine anti Ice system operate?

Answer 8

Controlled by ENG ANTI-ICE switches, ON or OFF on the ground and in flight in icing conditions (+10 TAT to -40 SAT with visible moisture, and/or visibility less than 1sm) FMC and EEC monitor the status of the switches.

Question 9

What is the logic associated with ENG ANT-ICE positioned to ON?

Answer 9

COWL VALVE OPEN - Cowl anti-ice valve opens
TAI displayed above N1 indication (EECs command approach idle) Sets stall warning for icing conditions (while switch is ON)

Question 10

What does a COWL ANTI-ICE (amber) light indicate?

Answer 10

overpressure within the cowl lip The ANTI-ICE annunciator and MASTER CAUTION lights will also illuminate.

Question 11

When does COWL ANTI-ICE illuminate/extinguish?

Answer 11

COWL ANTI-ICE = overpressure (greater than 65 psi) in the duct leading from the Cowl Anti-Ice Valve to the cowl lip. Extinguishes when condition no longer exists/valve is closed?

Question 12

What does a COWL VALVE OPEN bright blue light indicate? Dim blue? Extinguished?

Answer 12

(Bright Blue) COWL VALVE OPEN = the valve is in transit or disagrees with the ENG ANTI-ICE switch position
(Dim Blue) COWL VALVE OPEN = the valve is open with the ENG ANTI-ICE switch ON
The light is extinguished when the valve is closed and the switch is OFF

Question 13

What does an amber TAI indication above the engine N1 gauge mean? A green TAI?

Answer 13

(amber) TAI = the valve fails to move to the position selected by the ENG ANTI-ICE switch
(green) TAI = the valve is open with the ENG ANTI-ICE switch ON With TAI on, the EEC changes flight idle to approach idle

Question 14

What does the Wing Anti-Ice System protect from icing?

Answer 14

3 inboard slats only

Question 15

How is heat provided for wing anti-ice?

Answer 15

Bleed air

Question 16

How does the wing anti-ice system operate?

Answer 16

The WING ANTI-ICE switch controls the wing anti-ice control valve
Valve open = bleed air flows to slats then is exhausted overboard

Question 17

What is the logic associated with WING ANT-ICE positioned to ON?Off?

Answer 17

Stall speed increased for the rest of the flight

On the ground (shouldn’t be used on ground) lower overheat temp threshold, thrust lever advancement will turn them off

Question 18

How is wing anti-ice operation/logic different for ground ops vs in-flight?

Answer 18

On ground: valves open IF:
- Thrust is below config warning position (60 degrees)
- Temp inside ducts is less than thermal activation temperature (125 degrees))
Valves close IF: - Either engine thrust is above config warning position (53 degrees)
- An overheat

Question 19

What does a Wing Anti-Ice L or R VALVE OPEN bright blue light indicate?

Answer 19

L/R VALVE OPEN = in transit or disagree

Dim blue? L/R VALVE OPEN = switch on (valve agrees with switch) Extinguished? switch off (valve agrees with switch)

Question 20

With the PROBE HEAT switches in AUTO, under what conditions will heat be applied to probes?

Answer 20

After first engine start

Question 21

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

Answer 21

Electrical power not provided to prospective sensor

Question 22

When do they illuminate/extinguish?

Answer 22

Illuminate with a fault/failure, extinguish when operating normally

Question 23

What turns off wing anti ice on the ground?

Answer 23

Wing anti ice switch off
Thrust levers above angle
Overtemp within wing anti ice system