B737 NG Ice And Rain Protection Flashcards
What can happen if wing anti ice (WAI) is used above FL350?
Cabin pressure can be lost as well as ‘BLEED TRIP’ OFF.
When is CSFF (cold soaked fuel frost) allowable?
Provided all of the following conditions ARE met:
• Ambient air temperature is at or above +4°C+39°F
• There is no precipitation or visible moisture (rain, snow, drizzle, or fog with less than 1 mile visibility)
• Tank fuel temperature is at or above -16°C, +3°F
• All leading edge devices, all control surfaces, tab surfaces, winglet surfaces, and control surface balance panel cavities must be free of snow, ice and frost.
If all of the above conditions ARE NOT met, takeoff with light coatings of frost, up to 3 mm thick, on lower wing surfaces due to cold fuel is allowable; however, all leading edge devices, all control surfaces, tab surfaces, winglet surfaces and control surface balance panel cavities must be free of snow, ice and frost. If the frost on the lower surface is greater than 3 mm thick, all snow, ice and frost on the wings must be removed using appropriate deicing/anti-icing procedures.
What must the F/O check when switching on Probe heat switches?
… that all probe heat lights are extinguished.
Can the WAI be used for de-icing?
Yes
Should the engine anti ice be used for de-icing or anti icing?
Anti
How is the anti ice system controlled and actuated?
Electrically controlled with switches and pneumatically pressure actuated.
What happens to your IAS buffets when WAI or EAI is turned on?
SMYDS sets stall warning logic for icing conditions.
If only EAI was used, the logic disappears when EAI is turned off.
Stick shaker logic remains set for icing conditions for the remainder of the flight if WAI is used, regardless of subsequent WING ANTI–ICE switch position.
What indication can be used to indicate icing conditions?
Ice accumulation on the flight deck window frames, windshield center post, or on the windshield wiper arm
When PROBE HEAT switches are placed to auto, when is the Probe system heated?
Power is automatically supplied to both A and B probe heat systems when either engine is running.
Does the ‘Engine Bleed’ valve switch have to be ON for Engine anti ice to work?
No.
What causes the amber COWL ANTI–ICE light to illuminate?
Exceeded pressure ONLY (>65 psi) NG’s only.
On CL, OVER TEMP WILL ALSO TRIGGER
With WAI ON, when will the valves automatically close?
If either engine thrust is above the takeoff warning setting or either temperature sensor senses a duct overtemperature.
Does duct temperature and thrust setting logic work in flight in controlling WAI valve operation?
No
How long before take off must window heat be turned ON?
10 min
Are windows R3&L3 heated?
No
