carburetor heat on landing checklist

[Veddajoe]

Im sure this has been discussed before but I cant find it. I usually fly a Cirrus SR20/22 but for fun around the block I fly a 2006 CTLS  I haven't flown a carb airplane in years so forgot about the carb heat check. I was checked out in the CT last year snd never was told to use carb heat at all and cant find it in the manual that its needed. So what is the correct procedure on carb heat use ?

[Runtoeat]

The location of the bing carburetors on the Rotax, tucked in close to the engine and at the rear close to the firewall, provides good protection from icing.  Icing can occur when conditions are optimum such as high humidity and altitude  I have experienced icing a few times when flying at higher altitudes and high humidity but icing has never occurred when landing at the lower altitudes where I fly (Michigan).  Those who operate at higher altitudes may have different thoughts?

[Ed Cesnalis]

I fly mainly high altitude (dry climate) and haven't 'used my carb heat yet in 11 years.

[Mac Bowden]

In ten years of flying my Ct2k I have never used carb heat. I don't have  your system of hot air from the air box because I have Keihin filters directly on the carb intakes. I do have electric elements fitted to the carb throats which take about a minute to take effect but even with high humidity and dew point temperature close to air temperature I never felt the need to do anything regarding carb frosting. I'm not saying don't use carb heat just that I've never used it.

[FlyingMonkey]

I have used the carb heat a couple of times when conditions were right, but I doubt I really needed it.  FYI, I have read the 912ULS is most susceptible to icing at high humidity and around 60°F / 15.5°C.

[FlyingMonkey]

3 minutes ago, Mac Bowden said:

In ten years of flying my Ct2k I have never used carb heat. I don't have  your system of hot air from the air box because I have Keihin filters directly on the carb intakes. I do have electric elements fitted to the carb throats which take about a minute to take effect but even with high humidity and dew point temperature close to air temperature I never felt the need to do anything regarding carb frosting. I'm not saying don't use carb heat just that I've never used it.

If you have not used it in the damp British Isles, then I'd say the need for it is quite rare.  

Of course, if the engine gets rough without warning, we should all (try to) remember to use carb heat as a first attempt at a remedy.

[Ed Cesnalis]

In my Lycoming powered planes I pulled carb heat for every landing and every descent, it was mentally connected to the throttle.

In my CT I never use it but I do remind myself that it is there and the first place to go if I get rough running.

 

I get rough running at warm up / mag check when I leave the enricher in and I got it when rubber debris clogged my carbs but otherwise I turned down a carb balance yesterday, no point.

 

 

[Runtoeat]

I did get carb icing while flying over Pennsylvania in the summer.  The humidity was high and the temps were in the high 60's F at the 7,500' AGL altitude I was at.  At first, I detected reduced power and was scratching my head as to the cause for this.  Due to the lack of reports of carb icing on our Rotax engines, the thought that this might be the cause for the lack of power didn't register.  Not thinking it would make a difference, I pulled carb heat.  This initially caused rough running but soon resulted in increased engine rpm.  I'm providing some detail about my experience to let other Rotax owners know that carb icing did occur with me but this rarely occurs because the mode of engine operation and atmospheric conditions must be exactly right for it to happen.  

[ct9000]

Carb icing is very rare at cruise power but not uncommon at descent power settings. having said that different installations will alter the likelihood.  Lycomings in Pipers don't have much of a problem because they draw warmer air from under the cowl whereas Cessna's draw direct outside air which is colder and so icing is more likely for the same engine. I have had icing in my ctsw a number of times and so use carb heat in the cooler weather especially in higher humidity when power is set low.   

[Snoopyeagle]

CTs in the UK  aren't fitted with a Carb heat probably more to do with trying to keep the weight down to 450Kg rather than them not being required, In 15years of flying Cts over here I have never experienced Carb Icing, only once have I had a rough running engine on climb out and that we suspect was due to fuel line vapour locks caused by there being no fuel return line back to the fuel tanks.