SWA B737 - Anti Ice/Rain

Question 1

(Anti-Ice/Rain) How are the Engine Inlet Cowl Valves Operated?

Answer 1

Electrically Controlled - Pneumatically Operated

Question 2

(Anti-Ice/Rain) Can you still get Cowl Anti-Ice protection if the associated Engine Bleed Valve is closed?

Answer 2

Yes - the Cowl Anti-Ice valve is upstream of the Engine Bleed Valve

Question 3

(Anti-Ice/Rain) When you turn on the Engine Anti-Ice Valves on how does the airplane reconfigure itself?

Answer 3

• The Engine EEC’s reset the engine idle speed to approach idle.
• The stall warning logic adjusts on the stick shaker and minimum maneuver speed bars on the airspeed indicator. (These will return to normal upon turning the Engine Anti-Ice off, as long as the Wing Anti-Ice wasn’t used in flight)

Question 4

(Anti-Ice/Rain) What does a Bright Blue COWL VALVE OPEN light indicate?

Answer 4

• The Valve is in transit

* The Cowl Anti-Ice Valve position disagrees with the related switch

Question 5

(Anti-Ice/Rain) How do you know that both Cowl Anti-Ice valves opened after selecting them ON?

Answer 5

• The Bright Blue COWL VALVE OPEN lights dim; and

* Green TAI (Thermal Anti-Ice) indications appear on the N1 display.

Question 6

(Anti-Ice/Rain) You go to turn off the Cowl Anti-Ice and notice the Bright Blue COWL VALVE OPEN light, what other indications are there that will tell you the Valve is stuck open?

Answer 6

Amber TAI (Thermal Anti-Ice) indication in the N1 display

Question 7

(Anti-Ice/Rain) What does an illuminated COWL ANTI-ICE light on the Overhead Panel indicate?

Answer 7

An overpressure condition exists in the duct downstream of the Engine Cowl Anti-Ice Valve.

Question 8

(Anti-Ice/Rain) How are the Wing Anti-Ice Valves controlled?

Answer 8

Electrically (AC Powered). (These valves are purely electrically operated - NOT pneumatically operated).

Question 9

Anti-Ice/Rain) How should the Wing Anti-Ice Valves be configured for Takeoff?

Answer 9

Must ensure the Wing Anti-Ice Switch is OFF prior to beginning the Takeoff roll. (If you takeoff with them ON, the Valves will close automatically and as soon as the plane senses it is no longer on the Ground, the switch will flip to OFF)

Question 10

(Anti-Ice/Rain) How does the plane reconfigure itself when the Wing Anti-Ice is turned on?

Answer 10

The stall warning logic resets itself for icing conditions, however the logic stays for the remainder of the flight regardless of subsequent WING ANTI-ICE or ENG ANTI-ICE switch position.

Question 11

(Anti-Ice/Rain) What do the Green illuminated ON lights for the Window Heat indicate?

Answer 11

Electrical Power is being applied to the selected windows.

Question 12

(Anti-Ice/Rain) On the Window Heat Control you have a switch in the ON position, but no Green illuminated ON light - how can you test if the bulb is working or not?

Answer 12

Moving the Switch in the middle of the Window Heat Control Panel to PWR TEST will provide a confidence test of the ON lights.

Question 13

(Anti-Ice/Rain) What does an Illuminated OVERHEAT light on the Window Heat Panel indicate?

Answer 13

The temperature of the window exceeds a predetermined limit. (When this light illuminates, power is automatically removed from the selected window)

Question 14

(Anti-Ice/Rain) How do you perform an Overheat test of the windows?

Answer 14

Move the switch in the center of the Window Heat panel to OVHT, all the ON lights will extinguish and the OVERHEAT lights will illuminate. (To reset the windows you need to turn each switch OFF and then ON again)