Heated pitot temperature?

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robin ardoin

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How hot should my pitot tube get on a 182 with the heat turned on. My tube will get hot, but not uncomfortably so, after about 30-45 seconds of heat employed. What would be a reasonable temperature after a certain time?
 
robin ardoin said:
What would be a reasonable temperature after a certain time?
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On the ground, you should not be able to touch it nor want to. In the air I believe the spec is around 80 deg. Check the wiring for loose/dirty connections and see what the pitot heating element resistance is. For a 12v tube I think it should be around 2-4 ohms. Not a cheap thing to replace so best to make this one work if you actually need it.
 
@Bell206 28V system. I can easily hold it after the time it takes me to walk around the plane to verify lighting. I would say it is under 130 F. I'll leave it on for a couple of minutes next flight and re-eval. Thanks for your input.
 
Some will burn skin but I’d think with a C182 just warm (100 ish) to the touch would be enough to keep it clear.
 
Remember, it needs to be warm enough to keep it above freezing when being hit by water below freezing. It should be HOT. If you can grab it, it is not hot enough.
 
Pinecone said:
Remember, it needs to be warm enough to keep it above freezing when being hit by water below freezing. It should be HOT. If you can grab it, it is not hot enough.
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Just the flow of below-freezing air will cool it. Like you say, that heater has to be aggressive.

Just stick your hand out the window when the OAT is below freezing.
 
I just checked mine on a 172. Started out at 56f and after 60 seconds it was too hot to hold on to. After 4-5 minutes it was 180 at the base.
6 minutes it is 200. 8 minutes it is 215 degrees F. 10 minutes it is 235 and I shut it off. I think it will go hotter? 240 when I shut it off. I could smell it getting hotter. 28 v Was connected to ground power.
 
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I could easily palm mine at 60sec Gary. Crap...just back from annual in December :(.
 
Suggest you assure you have a good ground .

IIRC there is a disconnect in the wing root area.

Might be good to check this on a bench.
 
robin ardoin said:
Crap...just back from annual in December :(
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FYI: the only ops check I'm aware of for these type heat system is to turn system on and it should get warm to touch within X seconds which is usually 30-90 seconds. So yours passes the test.
 
Yours might very well be out of spec but the thing doesn’t have to burn your hand to work properly. Heated windshield plates aren’t very hot and glass windshields only heat to around 109-110F for anti-ice.
 
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I have melted more than one pitot tube cover in the hangar messing around with ground power and turning on the pitot heat. It no time the darn thing was melting.
I used a infra red heat temp gun before and the aluminum tip was still showing 60 something with the gun but putting my hand on it it was hot after just 60 seconds. Then I pointed it at the base and is where the heat starts from.
 
Cirrus, at least the later ones, have two settings controlled by the appropriate system automatically. On the ground it applies substantially less power than during flight. Even so, there is a limitation that says pitot heat should be on for no longer than 45 seconds to prevent damage to the composite in the wing. At 45 seconds the pitot tube is pretty warm.
 
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