Anti-Ice And 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
SEC 3.010, Page 7

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)
SH 3.010 pg 13

Question 3

Which Flight Deck windows are heated?

Answer 3

1 and #2 (both sides)

Question 4

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
OVERHEAT = 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)
SH 3.010 pg 3/4

Question 5

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

Answer 5

The engine cowl lip. SH 3.010 Page 7

Question 6

How is heat provided for engine anti-ice?

Answer 6

5th and 9th stage bleed air off the respective engine.
*if you close an engine bleed air valve you will still have anti-ice Sec 3.010, Page 7

Question 7

How does the system operate?

Answer 7

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.
Section 3.010, Page 7

Question 8

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

Answer 8

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)
SH 3.010, pg 8

Question 9

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

Answer 9

overpressure within the cowl lip
The ANTI-ICE annunciator and MASTER CAUTION lights will also illuminate. SH 3.010 pg 8

Question 10

When does it illuminate/extinguish?

Answer 10

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?
SH 3.010 pg 8

Question 11

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

Answer 11

COWL VALVE OPEN = the valve is in transit or disagrees with the ENG ANTI-ICE switch position
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
SH 3.010 pg 8

Question 12

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

Answer 12

TAI = the valve fails to move to the position selected by the ENG ANTI-ICE switch TAI = the valve is open with the ENG ANTI-ICE switch ON
With TAI on, the EEC changes flight idle to approach idle
SH 3.010 pg 9

Question 13

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

Answer 13

3 inboard slats only SH 3.010 pg 10

Question 14

How is heat provided for wing anti-ice?

Answer 14

Bleed air
SH 3.010 pg 10

Question 15

How does the system operate?

Answer 15

The WING ANTI-ICE switch controls the wing anti-ice control valve Valve open = bleed air flows to slats then is exhausted overboard SH 3.010 pg 10

Question 16

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

Answer 16

Stall speed increased for the rest of the flight
On the ground (shouldn’t be used on ground anyways) lower overheat temp threshold, thrust lever advancement will turn them off

Question 17

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

Answer 17

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 18

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

Answer 18

L/R VALVE OPEN = in transit or disagree

L/R VALVE OPEN = switch on (valve agrees with switch)

switch off (valve agrees with switch)

Question 19

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

Answer 19

After first engine start

Question 20

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

Answer 20

Electrical power not provided to prospective sensor

Illuminate with a fault/failure, extinguish when operating normally