Using Carburetor Heat While Flying

This Video explains Carburetor Heat procedures. When you should run Carburetor heat and how to detect Carburetor Icing and correct the issue.

[@floobblitz]

I had carb ice form during my Private check ride. :-) It was a classic day for it. Very humid, 60F. I was on downwind and the 152 I was in started to run rough as I took the plane to pattern altitude and 2000 rpm. Applied carb heat and it cleaned it right up. Was nerve racking though as the engine bucked and sputtered before coming back to smooth operation. That whole check ride was fabulous, first time seeing water in the fuel after sumping, carb ice, plane landing the "wrong" way as I was on final.

[@darkferiousity]

Hey Ayersaviation I am taking my private pilots license right now and I have to say you are the best flight instructor I have seen so far on the internet thanks man for the great videos

[@blackcoffin90]

Great simple "no scare tactics" tutorial. I am due to fly to YSCB tomorrow. Cold about 01C, rainy and cold breeze forecast.

[@fliboyHacksaw]

Google has plenty of Carb Ice Charts. Print one off, down size it, keep it on your knee board, or somewhere in your Airplane that it’s accessible. I do. If the conditions are right I can get Carb Ice in my One Fifty sitting on the ramp idling for goodness sake. Good Video Buddy!

[@Almostth3R]

Was curious about when to use card heat and have my checkride in 2 weeks. Needless to say it’s less than 70 degrees. Great video. Nice, clean, and precise. Thank you.

[@Ayersaviation]

Your welcome!! Glad it helped you out!

[@drcode4]

Thanks for this video. The instructors I have flown with in So. California don't recommend carb heat usage unless you need it. They say to do a carb heat "check" on downwind just to see if any ice has formed, but I didn't understand why every video I watched was telling me to use it, but my instructors were telling me not to. Thanks again.

[@wurstofall]

I am in So. California and getting my PPL and my instructor is always reminding me about carb heat when I forget. I must use carb heat every time I land. I guess it might just be a school thing or individual instructor thing.

[@jacobstump4414]

The scientific truth is that ice crystals are *always* forming in the carb. They’re usually small enough though to not do anything and flush out without intervention. But even in 90 degree heat, there are still some ice crystals forming just due to the physics of the Venturi in the carb. So the carb probability chart isn’t really “when does ice form?”, it’s actually “when does carb ice affect engine performance?” That’s the way to treat it. It’s always there, always trying to eat your carb, and you have to constantly keep it at bay through vigilant application of carb heat.

[@christippin6244]

Good information thank you much neighbor!

[@christoole1664]

Generally speaking, for a C152 or C172 apply carb heat (and leave on) anytime you reduce engine speed to 2,000 RPM or lower OR when your RPM’s drop below the green arc on your tachometer. This is generally speaking. For specific information on this, refer to your Pilot Operating Handbook (POH) for the year, make and model aircraft you are flying. Prevention (of carb ice) is the best cure. Staying “ahead” of your airplane is a best practice. CAVU everyone!

[@rinzler9775]

Depends on the aircraft, temperature, altitude, humidity. Running carb heat drops your fuel efficiency up to 10%.

[@observer1242]

I used to own a Piper Archer. Many do not recommend carb heat on this model due to air intake differences with Cessna. Is this true. I know Archer drivers who do not routinely use carb heat unless signs of ice. I don't believe its in the check list for landing when in the pattern. I could be wrong. It's been years since I sold my airplane.

[@SamLamsTop10Thankyoueveryone]

Good video

[@grummansteve]

I use the Carb Ice probability chart prior to every flight. I am often flying in conditions that allow Carb Ice to form at all power settings. My Yankee does not glide well so I am very cautious!

[@Ayersaviation]

Thats awesome!! great job thinking ahead and being prepared!!

[@michaelhall226]

Off topic - There is a meteor trail visible from about 0:58 to 1:06 sec on the RHS

[@refused215]

that's a good eye but looks like a reflection of something.

[@AmericusMaximus]

Would have been useful to have covered when not to use carburetor heat, given that it reduces engine output.

[@rackum44]

I am just a flight simmer but do you use carburetor heat on take off or just in slow flight?.cruise or landing?

[@Ayersaviation]

Just at low power settings such as Slow Flight, Descents, Landings, etc. never on take off or climbs because it reduces your engine power output by a little bit.

[@Vidster23]

thanks

[@zaxzaxerly9207]

Hi, ive got a question for you. Why dont aircraft manufacturers just build a carb ice detection system into the carburettor? It would save so much hassle and tension.

[@Ayersaviation]

Zax Zaxerly there are lots of things like that which would make flying easier and safer but I think it just comes down to being simplicity and cutting cost for manufacturers. There are after market products that will tell you what the internal temperature is inside the venture of the carb which helps.

[@zaxzaxerly9207]

Ayersaviation Ahh, that makes sense. Thanks for the information!

[@jacobstump4414]

Also it’s because a lot of the GA planes flying today are really old, and the engine designs are just as old too. So as a result there’s a huge market for overhaul and maintenance on older engines. And since you can’t convert an engine from carb to direct injection, carbs survive. I personally think it’s ridiculous that we’re still having to deal with carb icing in 2022. The technology exists to prevent or automatically manage it in so many different ways, but it just hasn’t been prioritized

[@RareSalmon93]

I'm confused as to why you use carb heat when going below the green arch. You said it was to prevent carb icing, but why is the risk of carb icing greater when the power is below the green arch?

[@Ayersaviation]

EXCELLENT QUESTION!! There is a "Butter Fly Valve" in the throat of the Carburetor.. During high power settings the Butter Fly Valve is nearly 100% open so it takes quite a bit of Carb Ice to kill the engine.... During Reduce power settings that Butterfly Valve is 1/2 Shut atleast so it takes 1/2 as much Carb ice to Kill the engine so there for it is a Higher Risk... Think of it as a Piece of trash in a Water line... If the Water Valve is Fulling open the Gunk has a greater Chance to work its way thru the valve.. Now imagine the impact if the Valve was half way shut.. It would have a greater chance in getting Hung up and restricting the water flow.

[@RareSalmon93]

Ayersaviation Oh! That's a great explanation and makes total sense. Thanks a lot for the response.

[@Ayersaviation]

The Flying Farmer our Cessna is a 1964 model with a Continental engine and we also own a 1960 and 1966 models 150's with Continental Engines. They all have Green arcs labeled on the tachs. I had to replace our Tach on our 172 that failed and the replacements all come labeled with green arcs that are model specific. All other points are correct about when to use carb heat. Thanks

[@lw216316]

how is it that you can get carb ice when the temp is well above freezing ?

[@Ayersaviation]

lw216316 increase of air velocity thru the carb drops the temperature

[@lw216316]

like wind chill factor the weather forecasters speak of....I suppose.... I would think the carb would be sheltered from the wind for that reason.... but I guess these are air cooled engines... makes me wonder why fuel injection is not used - seems float level would be a problem in steep turns and fail completely in a loop.....

[@lw216316]

thank you, very good explanation... that leads to another question- why not use fuel injection and eliminate the carb?.....cars did so long ago.

[@lw216316]

seems like the float level in a carb would be a problem for planes, in high bank and especially if inverted. What keeps the fuel from spilling or feeding properly ?

[@lw216316]

Would doing a loop in a Cessna 172 (1950s vintage) be risky ? Back in the 60s I knew a pilot who did that (not me - I'm not a pilot) but I was sitting next to him !

[@richardfuller2326]

We lost a crop duster! A pilot that was working for us, was pulling up over a tree line when he sucked a morning dove into the intake filter! Engine shut down. But had he pulled the carb heat, it would've bypassed the filter and kept running. P.S. the pilot was okay but the plane didn't!

[@rinzler9775]

Make sure your engine diagnostic checklist for your aircraft is burnt into memory.

[@pigslefats]

Why not always have hot air running through carburettor?

[@refused215]

i want to know the same thing.

[@Ayersaviation]

Air coming thru the carb heat system is unfiltered air so you could be putting dusty air into your engine. And you want to do that as little as possible. Less dirty than on the ground but still. Also the hot air makes the engine run leaner and less engine power is developed. That's why you have a decrease in engine power on the ground when you check your carb heat during engine run up. I hope this helps!

[@pigslefats]

Thanks. Could you explain how hot air equals a lean engine? Hot air is less dense than cold air, so there is less air in the cylinder? Which would mean a richer engine? Not sure about this though.

[@seanwatts8342]

Oxygen content is the same but hot air has less _pressure_ than cool air because of density.

[@seanwatts8342]

No, SAME AIR PER UNIT VOLUME it's just at a lower pressure. A liter of air is still a liter of air so the _CONTENT_ does not change, neither does the nitrogen, CO2 or any other gas in the air. The PARTIAL PRESSURE of all gasses drops (including pO2) because the AIR PRESSURE changes.