Which aircraft have a alternate air on the panel for air to the throttle body and how would your throttle body ice up do to carb ice ? There is no fuel going thru it.I know that most fuel injected aircraft have a spring loaded little flapper or door if you will behind the air filter that opens in the event it ices over and yes if it is the perfect conditions I suppose your throttle body could ice up if it got moister on it and then went through freezeing conditions,but it would be nothing like carb ice,because there is no fuel going through the throttle body.The little red knob on the panel that says "alt air supply" is for your static intruments only and has nothing to do with heat of any kind....
Bob Glidden Eminence,Indiana KR2S N181FW (building) Corvair 110 glid...@ccrtc.com