CRB ice detector... worth It?

WannFly

WannFly

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So, any feedback on carb ice detector? Is it worth it? Seems like a peace of mind to me, but what do u guys think?

I am aware of the symptoms and the troubleshooting steps if the motor runs rough... try carb heat, if it gets worse and then better, it's carb ice, if not, check mixture, then may. But with a carb ice detector it seems like the first step could be eliminated, assuming it's working.

Thoughts?

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We have one of the Archer at my flight school. Even with the sensitivity turned all the way down, it still detects ice. It's pretty much useless on our plane.
 
On what aircraft and powerplant combo?

The 182 is somewhat known for "making ice" and I wouldn't bother with it on ours. It'll run rough or lose a little power, so you pull on the heat and it coughs and sputters and carries on.

You'll probably want a Piper driver's opinion on yours but I wouldn't bother with one on ours.
 
jordane93 said:
We have one of the Archer at my flight school. Even with the sensitivity turned all the way down, it still detects ice. It's pretty much useless on our plane.
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Ha. Is it rigged RIGHT? I wouldn't think carb always have ice. But I do understand that it can happen pretty much anytime, especially with low power

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We have an EI electronic carb temp gauge in the 182P that JCranford and I fly in our club. Doubles as an OAT (additional probe). I find it nice to have to caution you that carb ice is possible. But I don't recall it ever being the reason I pulled carb heat outside of the normal routine.
 
AggieMike88 said:
We have an EI electronic carb temp gauge in the 182P that JCranford and I fly in our club. Doubles as an OAT (additional probe). I find it nice to have to caution you that carb ice is possible. But I don't recall it ever being the reason I pulled carb heat outside of the normal routine.
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This might be a Ford - Chevy thing, but the way I understand it, is the CRB probe detects the temp, not actual ice or frost. Or at least that's what the CRB ice detector companies say

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WannFly said:
This might be a Ford - Chevy thing, but the way I understand it, is the CRB probe detects the temp, not actual ice or frost. Or at least that's what the CRB ice detector companies say

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Click to expand...

If that's all it is, a temp gauge, it'll come on regularly. Just being at the temp for carb ice doesn't guarantee carb ice.

As @AggieMike88 said, the Cessna version is just a temp needle with a range that has been painted yellow.

In the few Cessnas I've been in that had it added as a factory option, it was generally useless because it was always in or moving through that range on every flight.

If all that silly thing is on Pipers is a light that comes on when the temp is in that range, I'd find it to be more of a distraction than useful.

Still: The specific airframe and powerplant is important to know. Then you look for folks who fly those and ask them whether they make ice.

The 182 *does* tend to, but it's something you just learn to recognize through poor performance. MP doesn't look right for the altitude, rough running, what feel like little engine misses... you pull the heat on and it melts immediately and the engine coughs on a blob of water going through it.

Let's put it this way. Over 300, pushing 350 hours in that single 182, and I've had to pull the carb heat on other than just doing it for normal landing procedure, three times. Granted, I'm flying in the dry high plains too, but folks will tell you the carb'd O-470 will make mountains of carb ice. Never really seen it, even when flying at wetter and denser air locales outside of weather so muggy you don't even want to be flying.

And that kinda weather would be where @AggieMike88 lives and he's also saying a known
"Icemaker" airplane doesn't do it there either.

So... I'd go look for stories of when yours makes ice and then just be aware of engine power. Tons and tons of aircraft don't have these.

Maui will be along shortly to tell you to invest in an AoA instead. Hahahaha.
 
From my reading, the O-320 configuration in the Cherokee is not known for making ice. In fact, the only direction to use it during flight is "as necessary." Precautionary use during low power operations isn't required.

I'd bet the carb is at icing temps pretty regularly, so having an indicator that ice making temperature is present doesn't seem terribly useful. That being said, if I get an engine monitor in my plane, I'll probably add a carb temp probe.

Carb ice detector, however, sounds gimmicky as all get out.
 
WannFly said:
Ha. Is it rigged RIGHT? I wouldn't think carb always have ice. But I do understand that it can happen pretty much anytime, especially with low power

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There's probably something wrong with it.
 
ircphoenix said:
From my reading, the O-320 configuration in the Cherokee is not known for making ice. In fact, the only direction to use it during flight is "as necessary." Precautionary use during low power operations isn't required.

I'd bet the carb is at icing temps pretty regularly, so having an indicator that ice making temperature is present doesn't seem terribly useful. That being said, if I get an engine monitor in my plane, I'll probably add a carb temp probe.

Carb ice detector, however, sounds gimmicky as all get out.
Click to expand...

:yeahthat:

With the notation that (I believe) the OP has an O-360 in his Cherokee. Neither engine has a reputation for carb icing. I've owned Cherokees with both those engines and that was my experience.

To the OP, there's lots of other things I would spend my airplane upgrade money on before resorting to a carb temperature gauge in a Cherokee.
 
denverpilot said:
As @AggieMike88 said, the Cessna version is just a temp needle with a range that has been painted yellow.
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We just get a steady yellow light. But as you said... it's more an advisory that carb ice could form, not that it will or has.
 
QUOTE="denverpilot, post: 2290378, member: 6717"]If that's all it is, a temp gauge, it'll come on regularly. Just being at the temp for carb ice doesn't guarantee carb ice.


Thanks, I will post in the piper forum and see what some 181 guys have to say. too bad for our Hawaiian friend.. but I already got one .... :p
 
GRG55 said:
:yeahthat:

With the notation that (I believe) the OP has an O-360 in his Cherokee. Neither engine has a reputation for carb icing. I've owned Cherokees with both those engines and that was my experience.

To the OP, there's lots of other things I would spend my airplane upgrade money on before resorting to a carb temperature gauge in a Cherokee.
Click to expand...
yepp. its a 360. thanks guys
 
AggieMike88 said:
We just get a steady yellow light. But as you said... it's more an advisory that carb ice could form, not that it will or has.
Click to expand...

Ahh. Sounds like an aftermarket on in your bird, then. That or it's a restart thing. What year is yours? The original from Cessna as an option on our 1975 is just a temp gauge.
 
I have this on my Cherokee. If gives me peace of mind if I'm flying into potential icing conditions. If nothing else the OAT is easier to read than that stupid unicorn temperature gauge installed on my windshield.

CA-1.jpg
 
Every carbed plane I've flown had a ice "detector", first the thing runs ruff, then I pull the heat, and runs worse, then better.

If you're looking to spend money lots of better places
 
In a cherokee/archer...I personally wouldn't spend my money on one. Our planes are not known to make ice much. That's why in the poh you will notice it never directs you to use it unless you suspect it. Unlike a Cessna. Like others have said, I'd spend my money on something else. Unless you get a Jpi that has it as part of it but I wouldn't spend the money for a stand alone carb ice gauge.
 
denverpilot said:
Ahh. Sounds like an aftermarket on in your bird, then. That or it's a restart thing. What year is yours? The original from Cessna as an option on our 1975 is just a temp gauge.
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It's the one that Timbeck2 pictured.
 
There are some carb ice detectors that have an optical probe in the throat of the carb that will "see" ice forming. We had them on the aeroclub planes in Korea. Theoretically, they're a wonderful idea but in practice the autogas we were using in Korea was fouling the lens of the probe and they were always indicating ice. How they would work if we used avgas, I don't know.

I put in the cheapest carb temp gauge in my C-150 (whose 0-200 could have been made by Frigidaire and marketed as an icemaker) and it was of some limited utility during warm days when you naturally don't think about icing and yet the carb temp is right down there where icing is possible. During the winter it was pretty much useless as the temp was always down where icing could be a problem.
 
I have carb temp on my 181 through my CGR-30P. Don't look at it a ton, but I do watch the numbers move when I pull my carb heat. At least tells me it's working.

WannFly said:
especially with low power
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This actually isn't true. Your carb temp goes up when you pull power out. If I follow the physics right, less fuel running through the carb so the pressure drop is less which means the temp drop is less. I think I got that right. :dunno: Seemed weird to me too, but as I pull power out for the descent, I can watch my carb temp rise on my CGR.
 
I have gotten carb ice several times in my Archer, and mostly, but not exclusively in low power situations. I'm always leary of it when practicing approaches, and certainly when the humidity is up. I thought of adding the carb temp probe to my EI Ubg-16, but other add ons were more pressing. I just use my carb heat for a few seconds whenever I think of it, and before landing for a few moments when going through the landing checklist and in long descents. I think it's a good discipline to get used to.
 
If anyone is interested, I have a brand new never installed ARP Carb Ice Detector. It’s the remote mount version. Comes with everything. Planned to install it and then sold plane. I like these a lot more than the carb temp probes. Will take $350 shipped to domestic USA address.
 
I have a 182H with a 0-470 and I pull the heat a lot. Live in NEPA and I’d like to think we have a lot of icing potential. Problem with ice is you can never prove it when someone augers in like dry tanks leave evidence. The proof melts away. If I have any reduced power setting I pull it. Even on those hot humid days. I will hear the engine make like a miss sound. Pull it. I think my mixture runs a bit rich though too. So sometimes at reduced power setting humid on approach I’ll hear that engine miss sound. Too rich?? Ice??
I don’t know what if there is any danger in using the heat more often. Thoughts?
 
NealRomeoGolf said:
This actually isn't true. Your carb temp goes up when you pull power out. If I follow the physics right, less fuel running through the carb so the pressure drop is less which means the temp drop is less. I think I got that right. :dunno: Seemed weird to me too, but as I pull power out for the descent, I can watch my carb temp rise on my CGR.
Click to expand...

Your physics could kill you. As you close the throttle, the fuel flow less, alright, but the pressure drop, instead of being at the venturi near the temp probe, moves to the edges of the throttle plate as it closes, and that drop gets really big. A big pressure drop means a big temperature drop. Boyle's Law. Both evaporative cooling and temp drop due to pressure drop are in play here. At low power settings, not idle, the two work together to drop the air temperature more than 70°F. And that's why the carb ice charts reflect that.

serveimage
 
Dan, you seem to be one of the more knowledgeable posters here so perhaps you can explain something on the carb ice chart that has always bothered me: Why are pressure carbs susceptible to icing at 80% RH but not 100%?
 
benyflyguy said:
I have a 182H with a 0-470 and I pull the heat a lot. Live in NEPA and I’d like to think we have a lot of icing potential. Problem with ice is you can never prove it when someone augers in like dry tanks leave evidence. The proof melts away. If I have any reduced power setting I pull it. Even on those hot humid days. I will hear the engine make like a miss sound. Pull it. I think my mixture runs a bit rich though too. So sometimes at reduced power setting humid on approach I’ll hear that engine miss sound. Too rich?? Ice??
I don’t know what if there is any danger in using the heat more often. Thoughts?
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For the reduced power during approaches in hot humid summer our 182 also rumbles/pops a bit but only with full carb heat. It is just running rich. During my PPL training on a lazy summer night at a Delta airport my CFI was wondering about this. We were cleared to land as we entered downwind. Per the POH I had pulled carb heat prior to entering the pattern. To experiment the CFI was able to pull the mixture knob out over 1.5" before it just started to stumble. Just prior to the stumble point it was running crazy smooth. Of course he had crap tons of time in 182 and 206, could land anything and all 3 runways were open and we were cleared on one of them. It is just running rich.

The other lesson is to not shove in the carb heat and then shove in the throttle quickly afterwards (like a go around). Either bring them in together or push in full throttle and remove the carb heat. I did the opposite on a touch and go and it sputtered and I aborted the takeoff.

IMHO The carb inlet temp gauge is absolutely useless, at least on the carb'd 182's As @denverpilot already mentioned its in the damn yellow zone almost all the time. It is a good confirmation that its working if you pull carb heat but you can also hear it and see it in the MP. If there was an actual ice detector with a flashing light I'd be interested. If you are getting a engine monitor probably might as well get it but once again not sure how useful it would be. If a Carb Ice detector and Carb Ice temperature sensor+gauge were the same $$$$ I'd get the detector first.
 
WannFly said:
carb ice detector
Click to expand...
The newer Archer at the club has one. The POH manual is pretty vague as far as setting it, I typically turn it on when reaching cruise altitude (cruise power set, carb heat off), I turn the knob just high enough to extinguish the "carb ice" light and leave it there. Seems to work okay enough. Two observations
-when I enter any kind of IMC the light illuminates. Engine sounds fine, but it's obviously picking up a chance, so I fire on the carb heat. There's no real risk at altitude of using it
-when I power down it starts to illuminate.. if I am VMC, no visible moisture, and engine sounds fine and it's warm out I'll generally leave the carb heat off and just turn up the knob a bit

jordane93 said:
Archer at my flight school. Even with the sensitivity turned all the way down, it still detects ice. It's pretty much useless on our plane
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Interesting, ours does not, see above
 
Tantalum said:
The newer Archer at the club has one. The POH manual is pretty vague as far as setting it, I typically turn it on when reaching cruise altitude (cruise power set, carb heat off), I turn the knob just high enough to extinguish the "carb ice" light and leave it there. Seems to work okay enough. Two observations
-when I enter any kind of IMC the light illuminates. Engine sounds fine, but it's obviously picking up a chance, so I fire on the carb heat. There's no real risk at altitude of using it
-when I power down it starts to illuminate.. if I am VMC, no visible moisture, and engine sounds fine and it's warm out I'll generally leave the carb heat off and just turn up the knob a bit


Interesting, ours does not, see above
Click to expand...
since i have put in the JPI 830 with a carb temp gauge..during a slow decent i set JPI to display the carb temp, if it stays about 40 degrees, i dont bother with carb heat unless there is visible moisture
 
Sinistar said:
For the reduced power during approaches in hot humid summer our 182 also rumbles/pops a bit but only with full carb heat. It is just running rich. During my PPL training on a lazy summer night at a Delta airport my CFI was wondering about this. We were cleared to land as we entered downwind. Per the POH I had pulled carb heat prior to entering the pattern. To experiment the CFI was able to pull the mixture knob out over 1.5" before it just started to stumble. Just prior to the stumble point it was running crazy smooth. Of course he had crap tons of time in 182 and 206, could land anything and all 3 runways were open and we were cleared on one of them. It is just running rich.

The other lesson is to not shove in the carb heat and then shove in the throttle quickly afterwards (like a go around). Either bring them in together or push in full throttle and remove the carb heat. I did the opposite on a touch and go and it sputtered and I aborted the takeoff.

IMHO The carb inlet temp gauge is absolutely useless, at least on the carb'd 182's As @denverpilot already mentioned its in the damn yellow zone almost all the time. It is a good confirmation that its working if you pull carb heat but you can also hear it and see it in the MP. If there was an actual ice detector with a flashing light I'd be interested. If you are getting a engine monitor probably might as well get it but once again not sure how useful it would be. If a Carb Ice detector and Carb Ice temperature sensor+gauge were the same $$$$ I'd get the detector first.
Click to expand...
I did the same thing on a t&g once and it sputtered and thankfully we were on the ground. Probably flooded it.
I was told to really watch for MP drop that’s unexplained. Once at altitude I lock the MP and then if I see it start to move a needlewidth I apply the heat.
 
flyingbrit said:
Dan, you seem to be one of the more knowledgeable posters here so perhaps you can explain something on the carb ice chart that has always bothered me: Why are pressure carbs susceptible to icing at 80% RH but not 100%?
Click to expand...

Never worked on one. They're pretty rare. But I could imagine that there's a spot in the throttle plate's travel where impact icing is possible. The venturi at the carb's air inlet causes a small pressure drop that could cause condensation of water vapor that could be supercooled water once past the venturi, and hit that partly-closed throttle plate and stick to it. Closing the plate further (reducing power) would reduce the venturi's pressure drop, and opening the throttle all the way (100 percent power) would minimize the plate's profile to the airflow. That's all speculation, and maybe someone else around here has some more experienced input.

Pressure carb looks like this:
1519429380682.jpg

Note that the fuel is injected downstream of the throttle plate, nowhere near it or the venturi, so any icing due to evaporative cooling would happen in the induction manifolding.

The venturi is there only to generate a vacuum signal, and a dynamic pressure signal is also generated by the impact tube nxt to the inlet. Both are used to meter the fuel. It's similar to the RSA (old Bendix) aircraft fuel injection systems, but the fuel is squirted into the airflow at the carb instead of into the intake ports at the cylinders.
 
Dan Thomas said:
Your physics could kill you. As you close the throttle, the fuel flow less, alright, but the pressure drop, instead of being at the venturi near the temp probe, moves to the edges of the throttle plate as it closes, and that drop gets really big. A big pressure drop means a big temperature drop. Boyle's Law. Both evaporative cooling and temp drop due to pressure drop are in play here. At low power settings, not idle, the two work together to drop the air temperature more than 70°F. And that's why the carb ice charts reflect that.

serveimage
Click to expand...
Dan,

Help me out here though with why my carb temp goes up when I pull power. Sample flight data from my CGR-30P.

Carb temp.JPG

At around 11:45, I pulled power and carb temp immediately rose a few degrees. You can then see spikes when I applied carb heat. In fact, only the first spike might be carb heat. I don't usually pull it twice (but I don't remember this particular flight). Then when I did the big pull for the approach, my carb heat rises more. I would assume the big rise was while I was on the ground so that has nothing to do with it. But here when I pull RPM, my carb temp rises. So what did I say wrong?

Engine: Lycoming O-360-A4M installed on a Piper Archer
 
NealRomeoGolf said:
Dan,

Help me out here though with why my carb temp goes up when I pull power. Sample flight data from my CGR-30P.

View attachment 84563

At around 11:45, I pulled power and carb temp immediately rose a few degrees. You can then see spikes when I applied carb heat. In fact, only the first spike might be carb heat. I don't usually pull it twice (but I don't remember this particular flight). Then when I did the big pull for the approach, my carb heat rises more. I would assume the big rise was while I was on the ground so that has nothing to do with it. But here when I pull RPM, my carb temp rises. So what did I say wrong?

Engine: Lycoming O-360-A4M installed on a Piper Archer
Click to expand...
The carb air temp sensor is between the venturi and throttle plate, and as the airflow slows through the venturi, the pressure drop due to velocity is less, and therefore the temperature drop is less, and the temp rises. When you pull the carb heat for approach, the temp rise will be large simply because the air being heated by the exhaust system is less and moving more slowly through the heat exchanger. If you went to full power, that temp would drop.

serveimage


If we had that temp probe right at the edge of the throttle plate when it's open just a bit, we'd see a frightening temperature drop. There is no ideal place for it. The temp will be lower than indicated in the venturi itself and much lower than indicated at a spot where the plate is open 1/8" or so.

serveimage
 
NebC said:
If anyone is interested, I have a brand new never installed ARP Carb Ice Detector. It’s the remote mount version. Comes with everything. Planned to install it and then sold plane. I like these a lot more than the carb temp probes. Will take $350 shipped to domestic USA address.
Click to expand...
 
Do you still have that ARP Ice Detector by chance? I’m interested in it.
 
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