carb Ice
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Joined: Apr 2008
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From: nowhere
carb Ice
Been reading up on it lately. I am curious if anybody in their flying experience has found a particular aircraft, engine or carb type more or less susceptable to getting ice.
Especially if more. Any aircraft in particular to watch out for.
Thanks
Especially if more. Any aircraft in particular to watch out for.
Thanks
Joined: Dec 2011
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From: Stuttgart, Germany
The bigger the engine, the more likely to encounter I would say (stronger Bernoulli effect). I fly a Cessna TR182 with a turbocharged carbureted O-540 engine and it is very sensitive to carb ice.
Carb ice is easier to detect with a fixed prop because the reduction in RPM is very noticeable. With a constant speed prob, it is less evident. You see a drop in manifold pressure but the airplane will not "feel" different, only when it might be too late.
The TR182 got a carburetor temperatur gauge to address this. Pilot has to make sure it stay outside of the yellow arc.
Personally I think it's not something to be afraid of if you know about it and keep looking for signs. Once turning on the carb heat, it takes about 10-30s to get back to normal in my experience.
Carb ice is easier to detect with a fixed prop because the reduction in RPM is very noticeable. With a constant speed prob, it is less evident. You see a drop in manifold pressure but the airplane will not "feel" different, only when it might be too late.
The TR182 got a carburetor temperatur gauge to address this. Pilot has to make sure it stay outside of the yellow arc.
Personally I think it's not something to be afraid of if you know about it and keep looking for signs. Once turning on the carb heat, it takes about 10-30s to get back to normal in my experience.
Joined: Jul 2009
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From: UK
Small Continentals are said to be more prone to carb ice, because the carburettor is more exposed. Liberal use of carb heat helps with these, particularly in the circuit. Bear in mind the fact that this effectively causes the mixture to become more rich, so care of the plugs is important.
Kinner Radial engines are also known to be more susceptible to carb ice.
In either case, being aware of likelihood of icing conditions is a key to mitigation.
The worst carb ice I ever had was my first car, a clapped out Ford Fiesta. In freezing fog on the motorway, my top speed dropped from 60 (it was old!) through 50 to 40 at which point I pulled over. It was late at night and no traffic, otherwise I'd have pulled over sooner. Anyway, 15 minutes later it ran fine. On inspection, the air box had fallen off, having been attached with a single wood screw so the intake was cold air only. I treat carb ice with much respect after that experience...
Kinner Radial engines are also known to be more susceptible to carb ice.
In either case, being aware of likelihood of icing conditions is a key to mitigation.
The worst carb ice I ever had was my first car, a clapped out Ford Fiesta. In freezing fog on the motorway, my top speed dropped from 60 (it was old!) through 50 to 40 at which point I pulled over. It was late at night and no traffic, otherwise I'd have pulled over sooner. Anyway, 15 minutes later it ran fine. On inspection, the air box had fallen off, having been attached with a single wood screw so the intake was cold air only. I treat carb ice with much respect after that experience...
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From: UK
Smaller continentals definitely.
The main aeroplanes I've seen carb ice on are Super Cubs and older C150s, often at its worst whilst on the ground.
912 engined modern microlights, and reasonably modern PA28s are probably the least problematic in my experience. The PA28-161 manual even tells you NOT to use carb heat on approach unless you see positive signs of carb icing (although a lamentably large number of flying instructors are convinced that they know better than Piper in this regard and make students use carb heat on approach, effectively flying them like Cessnas, which do need it.)
G
The main aeroplanes I've seen carb ice on are Super Cubs and older C150s, often at its worst whilst on the ground.
912 engined modern microlights, and reasonably modern PA28s are probably the least problematic in my experience. The PA28-161 manual even tells you NOT to use carb heat on approach unless you see positive signs of carb icing (although a lamentably large number of flying instructors are convinced that they know better than Piper in this regard and make students use carb heat on approach, effectively flying them like Cessnas, which do need it.)
G
Joined: Sep 2004
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From: Here and there
The Cessna 152 was less prone to icing than the C150 because it has the 0-235 engine where the intake manifold passes through the engine sump allowing the oil to partially warm the air. The C150, on the other hand, has the 0-200 where the intake manifold is not embedded in the engine.
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From: SoCal
Continental O-300 in a C172: worst carb ice I ever had, in fact the only engine installation I ever flew that had serious icing issues (some of the old bangers I drove in much younger years had too, but there was always the option of pulling over and waiting a bit.... depending on the company, not always such a bad thing 
)
)
Thread Starter
Joined: Apr 2008
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From: nowhere
That's interesting. I have some recent experience on a Kinner engine. I did put carb heat on on a regular basis but only as a precaution. Where did you hear about the Kinner and Carb ice.
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From: UK
The main aeroplanes I've seen carb ice on are Super Cubs and older C150s, often at its worst whilst on the ground.
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From: ...back of the drag curve
I'm amazed that in these days of technology, we haven't yet managed to eradicate accidents that are due to carb icing. As always, there are a lot of old wives tales out there.
Anyway, I digress. In my experience, Continental A-65 and C-90 are both prone to carb icing if allowed to be, together with VWs. Somebody managed to stop the engine of our C90 engined Cub on finals even though he had selected heat on finals (although i suspect he didnt select it for long enough). Many pilots I fly with only use it for 5 or so seconds which is no use to anyone.
On larger radials, R985 & R1340, I have never needed to use carb heat.
Anyway, I digress. In my experience, Continental A-65 and C-90 are both prone to carb icing if allowed to be, together with VWs. Somebody managed to stop the engine of our C90 engined Cub on finals even though he had selected heat on finals (although i suspect he didnt select it for long enough). Many pilots I fly with only use it for 5 or so seconds which is no use to anyone.
On larger radials, R985 & R1340, I have never needed to use carb heat.
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From: UK
The Cessna 152 was less prone to icing than the C150 because it has the 0-235 engine where the intake manifold passes through the engine sump allowing the oil to partially warm the air.
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From: UK
I'm amazed that in these days of technology, we haven't yet managed to eradicate accidents that are due to carb icing. As always, there are a lot of old wives tales out there.
It's just that so much of our community is still in love with such geriatric technology.
G
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From: 23, Railway Cuttings, East Cheam
I've had carb icing once while airborne in a PA28 on a hot summer's day. Engine just sounded rough and the yoke was vibrating, selection of carb heat cleared it in half a minute or so. Funnily enough I'd just done the FREDA checks a couple of minutes before as well.
I've had it on the ground a few times while waiting for the oil temeperature to warm up after start, that's in 152's, 172's and 28's.
I've had it on the ground a few times while waiting for the oil temeperature to warm up after start, that's in 152's, 172's and 28's.
Avoid imitations
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From: Wandering the FIR and cyberspace often at highly unsociable times
Interesting that it is affected by carb ice. Turbo charging compresses and heats up the air so it is rare to get icing in my experience.
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From: UK
When I had my Rotax they supplied an electric heated port that fitted on the carb. I never had carb ice although I wouldn't claim it was totally due to that. I would have thought that some enterprising person could duct exhaust gasses around the carb to keep it hot rather than putting exhaust gasses into the air intake.
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From: Earth
912 engined modern microlights, and reasonably modern PA28s are probably the least problematic in my experience
Looking forwards to someone saying they are extra careful on frosty mornings....
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From: Up North
It's just that so much of our community is still in love with such geriatric technology.
Not so sure that the majority of mainstream GA like flying around in aircraft which are particularly susceptible to carb. icing. While there's certainly an element of appreciation of the geriatric, I'd certainly buy a simple cure for carb. icing if it was available to retrofit. But it's not is it, and the reason for that isn't a lack of demand, or love of the black art of appropriate application of carb. heat, it's the onerous and outrageously expensive certification requirements for a solution.
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From: UK
The only time I've had carb icing in flight with noticable effect was in a duchess in IMC.
Other than that, you usually get it on the ground, or use carb heat liberally in flight if you know you're in high risk conditions. I'm sure you're aware of the table showing temp against dew point with the likely carb ice risks, availiable in most textbooks and LASORS.
Other than that, you usually get it on the ground, or use carb heat liberally in flight if you know you're in high risk conditions. I'm sure you're aware of the table showing temp against dew point with the likely carb ice risks, availiable in most textbooks and LASORS.
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I would never buy a plane with a carb.
There are enough things in this game which can bite you, without having this one to worry about. Brunel would have designed this deathtrap out, but for some reason the GA community accepts it.
The old (certified) engines we fly with are very very reliable. You just have to keep that hole in the front open so the air and juice can get in
There are enough things in this game which can bite you, without having this one to worry about. Brunel would have designed this deathtrap out, but for some reason the GA community accepts it.
The old (certified) engines we fly with are very very reliable. You just have to keep that hole in the front open so the air and juice can get in