Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Kemble Pitts
#1862023
Joe Dell wrote:On final, leave carb heat on all the way to the ground. :(


Me too. I don't see any benefit in putting the carb heat away before I've finished the landing roll. Its easy enough to quickly go to 'cold' on a go around if required.

I taxy out with carb heat, cos I'm about to go flying and don't want ice, taxy back in without carb heat as I'd rather have improved filtration to minimise engine wear.

Just the way I play it.
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By Rob L
#1862046
Most pilots here in the UK learn to fly in 152s, 172s, Pa28s etc, all fitted with Lycomings.
The manuals therein call for carb heat to cold at 300 feet on final approach "in case of a go-around" (or words to that effect). Why?

I would be concerned about flying in an aircraft whos performance is so degraded with carb heat in the hot position upon a go-around that it would be a go-around flight-safety issue.

[In full disclosure: I learned in a C152, and did the appropriate "Technical" ground exam, but I didn't really learn or understand about carb ice until I got a share in an aircraft with a small Continental.]

Rob
By Crash one
#1862072
I’ve done numerous touch and go, go arounds on 600 metres grass, routinely forgetting to put it back to cold. No noticeable difference in power. Perhaps not a good idea to leave it hot all the time in case it gets iced up at that and I’ve got nothing else!
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By Rob L
#1862074
Crash one wrote:I’ve done numerous touch and go, go arounds on 600 metres grass, routinely forgetting to put it back to cold. No noticeable difference in power. Perhaps not a good idea to leave it hot all the time in case it gets iced up at that and I’ve got nothing else!


I generally agree :thumright: , but if flying with a Stromberg carburetor like mine; you should be careful not to foul the sparking plugs with too rich a mixture for too long. [Just a little friendly word of warning].

And now that I've said that, I could run mine with a Stromberg all year long with carb heat out (hot) and never have any trouble :eye: .

But: many C-85s and C-90s (and most of all the O-200 and O-300 engines) use a Marvel-Schebler carburetor; so handling & operating rules for those are very different.

Rob
By condor17
#1862080
We've found a lot of top tips in Harry Fentons site , Guide to Small Continentals . Off the Bowers Flybaby site ..

http://www.bowersflybaby.com/tech/fenton.html

rgds condor .

PS . Only pointed out to me 2 yrs ago that Lyc. inlet tubes pass through ..ish the oil tank , thus warming the mixture ..
Conts. inlet tube is always in cold freestream air in front of the oil tank /tube . Thus more ice .
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User avatar
By Rob L
#1862081
condor17 wrote:...2 yrs ago....


I knew that 35 years ago; where is the education now?
Is that not taught in the modern "Technical PPL exams (sic)" or whatever they're called now?
No reflection on you, condor17; it's more of a rhetorical question.

Rob
By Bill McCarthy
#1862082
We can send stuff to the moon and Mars, yet controlling carb temperature in a wheezy old donk seems beyond us. Fuel injection sorts it out for many of course. The Merlin had the carb butterfly valve within the carb heated by hot engine oil to keep the throat clear of ice.
By condor17
#1862084
Just returned to Cambridge behind an O-200 last week , where it all started 50yrs ago on 150s . Didn't know then .. Followed by 18 months on Pa28 Lycs.. 25 yrs behind an O-200 , Last 12 mostly Lycs.. still unknown .
That kind of knowledge is not in tech courses , more word of mouth from highly experienced 'thinking' pilots .

But then I'm an Old 'Naarfick tractor driver with wings .

rgds condor
By Dino
#1862110
condor17 wrote:...
PS . Only pointed out to me 2 yrs ago that Lyc. inlet tubes pass through ..ish the oil tank , thus warming the mixture ...

Agreed but that's after the carb. The ice forms in the carb throat doesn't it?
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By PeteM
#1866634
Harry Fenton's site is one of those that needs more awareness.

My Stromberg was wired 'fully rich', because certain people thought(??) the mixture system was ineffective.

A little research and I had a full operative mixture system - happy to take me to 10,000 feet (although it took quite awhile!).

It is unfortunate that so many modern manuals are about liability avoidance rahter than real education!
By PeteM
#1866667
Well actually a couple of times to see if it was possible - but it did mean that getting over the transition was much less of an issue! And it saved me a fair bit on beer money!