737NG EAI & WAI operation
 

Hi, I'm just wondering what are the procedures relating to Engine Anti Ice and Wing Anti Ice. I'm particularly interested in its operation with Boeing 737NG models. I understand that they are not turned on above 10°c. I'm just wondering would they be turned on if the temperature drops below this for all stages of the flight until the temperature goes back above 10°c? Thanks for your help! :)

TAI (engine)

Quick & Dirty:
Visible moisture and:
Ground ops and Climb, TAT/OAT +10C = ON
Climb and Cruise, SAT drops to -40C = OFF
Descent and Ground ops, TAT/OAT +10C = ON
Greater than +10C, OFF
No moisture, OFF

Below SAT -40 but with thunderstorms in vicinity: ON

Below SAT -40 but with thunderstorms in vicinity: ON

Is that personal opinion or manufacturer's? Define vicinity if VMC.

Here's a common sense question reading between the lines. SAT >-40c, but you are IMC in descent, BUT you are doing V/S 1000fpm with >70% N1% thrust. EAI ON/OFF? You are in CRZ medium level >-40c: N1% >70% EAI OFF SOP. So what's the difference? I suspect the EAI ON in descent even when >-40c is the expectation to being doing an idle power descent with only FLT Idle for protection. What do you do in the 1st scenario?

Rat5,

Personal in IMC and with CB or TS reported, especially in the ITCZ.

Not a manufacturer mandated procedure, neither is it SOP.

Interesting, Thanks! :)