Carb heat questions

[Phlash 0]

Hi, a couple of carb heat issues, most likely pilot error.

 

1. After landing and taxing to the terminal in a very warm region ambient 40c, carb heat is fine with the engines running, I then shutdown to park, once every thing is off, cold and dark after about a minute a message pops up stating carb heat is causing engine damage, if I open the Maintenance Manager I can see the engines go from green, yellow, orange, red to black. If I turn power back on to observe carb temp they are all sitting at about 40c. How do I prevent this short of staying out of hot climates?

 

2. If I utilize the AFE during cruise, once the AFE status is in maintaining mode, it moves all the Carb Air preheats to the full down position if I try to reposition the carb preheat to adjust the Carb Air temp up, the AFE will move them back to the full down position again allowing the carb air temp to drop out of range. Is this normal as I would think the AFE should be concerned about carb air temp while maintaining.

 

Thanks,

[sizziano 172]

1. This is a known bug.

[Phlash 0]

sizziano, Thanks for the info

[scandinavian13 5,192]

 

 

Is this normal as I would think the AFE should be concerned about carb air temp while maintaining.

 

He is. The problem is not that the AFE isn't unconcerned. The problem is that you're concerned when you're not supposed to be. Ice requires cold plus water. I'm guessing you might've just seen the cold temperature in the carb throat and assumed you needed to warm it up?

[Phlash 0]

Yep, that's it exactly, figured I was missing something.

 

Thanks

[gnomegemini 7]

Carb icing is only occuring when in yellow "danger" area on gauge AND there is moisture. I'm wondering if you have more power when carb temp is lower? Because you use less MP with lower temp in carb.

[downscc 1,327]

 

 

I'm wondering if you have more power when carb temp is lower? Because you use less MP with lower temp in carb.

 

The cooler air is denser, so you are getting more air by weight and more power.  Carb heat will cost you power for the same reason plus the induction drag added by the heater plumbing.