Too Cold for Flight

Matthew said:
When it's too cold to preflight, it's too cold to fly.
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Well said.

Does it make a difference if I can pre-flight indoors in a heated hangar, load up and then get line department to pull me out of the heated hangar while I sit FD&H in the warm airplane?:)
 
bnt83 said:
Does it make a difference if I can pre-flight indoors in a heated hangar, load up and then get line department to pull me out of the heated hangar while I sit FD&H in the warm airplane?:)
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We do that most days we fly this time of year! :thumbsup: :thumbsup:
 
LDJones said:
How'd the heater work??!
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I darn near froze in the cockpit. :rolleyes::rofl:

It was also the most turbulent flight Ive ever flown. (cold enough to be brisk but not enough to smooth the air our) Hit some pockets where I had full aileron in and was still rolling in the opposite direction. And the wind shifted so it was also my strongest crosswind landing. Didnt do to bad but im not publishing that video. :D:goofy:
 
My record is taking off at -20C in the 310 (preheated), which I tied in the Mooney. At altitude in the 310 I was getting -40C. The plane absolutely loved it. And, fortunately, the 310 has a wonderful heater!
 
Ted DuPuis said:
My record is taking off at -20C in the 310 (preheated), which I tied in the Mooney. At altitude in the 310 I was getting -40C. The plane absolutely loved it. And, fortunately, the 310 has a wonderful heater!
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I've never flown something with a MP gauge in weather that cold, what kind of MP do you see on the ground, and then at altitude? Could one in theory "overboost" a NA engine on the ground?
 
Arbiter419 said:
I've never flown something with a MP gauge in weather that cold, what kind of MP do you see on the ground, and then at altitude? Could one in theory "overboost" a NA engine on the ground?
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:confused:......

MP gauge will read barometric pressure... If the airport is at sea level and a strong high pressure area is over the field then you could possibly see 30.80.. A NA motor is rated based on standard day numbers... 29.92, 59f and 0 humidity.... So, in reality those motors will be slightly boosted over stock... A turbo motor will get to the wastegate setting and stay there... The cold air will definately help in the VE numbers though.. :yes: IMHO
 
N801BH said:
:confused:......

MP gauge will read barometric pressure... If the airport is at sea level and a strong high pressure area is over the field then you could possibly see 30.80.. A NA motor is rated based on standard day numbers... 29.92, 59f and 0 humidity.... So, in reality those motors will be slightly boosted over stock... A turbo motor will get to the wastegate setting and stay there... The cold air will definately help in the VE numbers though.. :yes: IMHO
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Right, sorry...confusing DA and barometric pressure. I had just woken up from a nap!
 
The only thing colder than aluminum on a cold morning is avgas. That stuff just wicks away all the heat in your hands.
 
Swampfox201 said:
Ok you got me someone please help me with the term. They went in the front just like cowl plugs but they were somehow secured in place and they blocked the majority of the air from entering and cooling the engine. Anyone know what they are called? Its the only time I remember using them. My CFI was PIC. I was just the frozen stiff who was dumb enough to say "yes" when asked if I wanted to go along.
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I think my FBO has the same thing on their 172. Plastic plugs that cover about half the cowl opening and are secured with screws.

Up here if we didnt fly in cold weather we wouldn't fly much this time of year.
 
When is it too cold ? It's not so much the flying, but just the ground handling of the plane. Once temps drop below -10F I just dont want to touch a plane, even with gloves. Pre-flighting in a heated hangar makes it somewhat bearable, but unless you can just leave the plane to a lineman to tow it into the hangar at the destination, you are still stuck.

I had the cabin heater give up the ghost in the PA30. It was -20 at my cruise altitude, you get cold feet in a hurry.

You have to know your planes limitations though. A ferry pilot perished a number of years ago when the condensation in the crankcase vent on the SR20 he was flying froze and the engine dumped out all its oil 4-5 hours into the flight. He had to ditch off greenland and didn't survive it despite survival gear.
 
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I ride snowmobiles up here in occasional 0 and sub-0 days. A lot of mornings I get up and it's single digit temps. I've just gotten acclimatized to it now to where if I go out and it's in the 20s I don't even bother to zip my jacket up or put gloves on.
 
weilke said:
You have to know your planes limitations though. A ferry pilot perished a number of years ago when the condensation in the crankcase vent on the SR20 he was flying froze and the engine dumped out all its oil 4-5 hours into the flight. He had to ditch off greenland and didn't survive it despite survival gear.
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Is there a printed limitation for minimum temperature ?

You guys are speaking of temperatures I have never come close to experiencing. The coldest temps I can remember seeing are around 3-4 degrees driving up to sugar mountain one year.
 
dell30rb said:
Is there a printed limitation for minimum temperature ?

You guys are speaking of temperatures I have never come close to experiencing. The coldest temps I can remember seeing are around 3-4 degrees driving up to sugar mountain one year.
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3-4 degrees..:dunno:..

That is short sleeve weather out here...:yes:;)
 
Last time I got out was this past Sunday. It was almost 20 degrees Fahrenheit. With the sun shining, and after so many days of temperatures hovering near or below zero, I felt overdressed with my hat and gloves. I guess it's all relative. :)
 
Arbiter419 said:
I've never flown something with a MP gauge in weather that cold, what kind of MP do you see on the ground, and then at altitude? Could one in theory "overboost" a NA engine on the ground?
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As Ben pointed out, your manifold pressures will be whatever they will be.

Your engine will be making more power than it was rated for, which means higher pressures in the cylinder, and theoretically more wear and tear. If you were worried about that, you could choose to take off at a reduced throttle setting, but it wouldn't worry me.
 
dell30rb said:
Is there a printed limitation for minimum temperature ?
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This is what a Cirrus SR20 poh I found online has to say in section 2-15 under 'limitations':

Environmental Conditions
For operation of the airplane below an outside air temperature of -10°F
(-23° C), use of cowl inlet covers approved by Cirrus Design and listed
in the Winterization Kit AFM Supplement P/N 11934-S25 is required.

This may be specific to the SR20 and not apply to the SR22 with its very different engine. The problem as I understand it is that the steam from the CCV freezes in the exposed CCV tube. The winterization kit slows down the airflow enough to keep the tube warm enough for that not to occur.

You guys are speaking of temperatures I have never come close to experiencing. The coldest temps I can remember seeing are around 3-4 degrees driving up to sugar mountain one year.
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And as my father in law who hails from a tropical climate and visited us in Fargo, ND told me: ......nobody should have to live at those temperatures. You could get hurt !
 
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The crank vent tube freezing is not something I have previously considered.

One issue we have is that the cub won't run hot enough to burn the water out of the oil in the winter. At 50 degrees OAT it will barely make 140 degrees oil temp in cruise. At the advice of our a&p I 'hang it off the prop' - climb somewhere around Vx with some slip up to 3-4000 feet. Level off for a bit so cht can stabilize and then spin a couple turns to get back down
 
N801BH said:
3-4 degrees..:dunno:..

That is short sleeve weather out here...:yes:;)
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Dude, you're in sneakers and shirt sleeves at -20, that's why it was too cold for you to fly...:rofl::rofl::rofl: I was comfy, it was a bit chilly on the snow machine though.
 
flyingmoose said:
gkaiser said:
Our club's rules is no flight under 0 degrees Fahrenheit.
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Why?
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I think that it may be related to mixture. Our club's rules are no T&G below 0, and no flight below -20. I've flown the 182 in sub-zero (F) conditions several times. Once, I swear I looked at the mixture knob and the engine stumbled. :rofl:

I've flown the same airplane across about a 110-degree span of temperatures... And most of the time it's toward the warmer end of that span. I think that when it gets REALLY cold, full rich may even be lean of peak.

For an Alaskan airplane, they'd set the rich mixture differently, which is why they do just fine in colder temps up there while we have temperature rules they'd scoff at.
 
tangopapa said:
I know the feeling... but if you're renting at your local FBO, shouldn't the line guy have preheated the engine for you?
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I've rented at some fairly large, well-run FBOs (well, flight schools) and never seen a "line guy" available to provide any assistance to renters. Always had to pre-heat the plane myself.
 
gkaiser said:
...how long have you had to wait for the oil temp to go into the green?
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I idle my O-360 at 1100 RPM till the oil gets to 80 degrees F, then do a runup. I won't takeoff till the oil gets to 100 degrees F. Yesterday's flight was at 34 degrees F, and the oil took 7 minutes to get to 80, which gave me time to set the radios, compass, program the GPS, check flight controls, and all other runup items short of mags, prop, and carb heat. The oil was at 100 degrees by the time I was done with the runup.
 
the -30 does not happen in NJ too often -but even so when its even 0F in NJ it warms up usually as your ascend.

If you look at a 20-25F high day in NJ and then look at the Skew-T I'd be willing to be on most of those days the temp goes up as you climb out.

When my airplane was in a heated common hangar in Connecticut I recall departing one mid December day when it was 4F out. On the [very short] climb out with 300hp in a Viking and just me it was 32F at 8000'. Clear as a bell - not a cloud in the sky - no surprise with that kind of inversion. I recall being airborne at the 500' marker on the runway - density altitude was something on the order of -4000' . . .

I have flown often in the temps you describe - bring a hat in case the heater is not as effective as you might hope - and gloves -
 
We're having a cold snap here, too. Only expected to reach 64 °F tomorrow. BRRRR. I have the C-172 reserved to get going again on my IR. Hope the heater works!
 
"The Glacier Pilot" the story of Bob Reeve's life says he flew the Fairchild 71 at -70 something.

The winterization kits will allow you to operate way below any temps mentioned here. A friend operates his Beaver at -40 almost every winter out of Fairbanks.
 
I remember listening to an aviation podcast where they were talking really cold and how it was at the limits of what a carburetor could do. Any colder and the fuel would not atomize right.

Anyone know if this is true and how cold it would have to get for 100LL to not work right in a carburetor?
 
Swampfox201 said:
I remember listening to an aviation podcast where they were talking really cold and how it was at the limits of what a carburetor could do. Any colder and the fuel would not atomize right.

Anyone know if this is true and how cold it would have to get for 100LL to not work right in a carburetor?
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Pretty cold.

The fuel runs along the runners as a liquid and shears off on the valve seat where it mixes with the air. Heat from compression and previous combustion evaporates it in the cylinder.

The hard part is getting it started in the first place - once you have that you are good to go. If you pre-heat the starting is a lot easier.

-40 can be done with carburetor even without pre-heat (BTDT with cars in a -40 "cold room" at one of the larger auto companies)
 
JohnAJohnson said:
Are you sure?
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Yes.

Back in the olden days it was common to build clear plastic intake manifolds to observe the flow of the fuel to the cylinders (and to play around with the configuration to make the flow more even). Even when armed up an engine with a carburetor or throttle body injection will have liquid fuel flowing down surface of the runners to the cylinders.

With intake port injection, some fuel remains as suspended droplets and some evaporates, but much of the fuel ends up on the walls / back of the intake valve where it is sheared off by the intake flow.

Isn't there vacuum from the throttle plate onward?
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Not much vacuum when you are cranking, but some.
 
Swampfox201 said:
I remember listening to an aviation podcast where they were talking really cold and how it was at the limits of what a carburetor could do. Any colder and the fuel would not atomize right.

Anyone know if this is true and how cold it would have to get for 100LL to not work right in a carburetor?
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You just use some carb heat to get the engine running smoothly. Engines will run in extremely cold conditions, especially on gasoline, plenty of waste heat involved and a low vapor temp; you just need to prime a bunch including when cranking 4-6 blades and then let all that fuel sit and vaporize. Never pump the throttle when not cranking.
 
flyingcheesehead said:
I think that it may be related to mixture. Our club's rules are no T&G below 0, and no flight below -20. I've flown the 182 in sub-zero (F) conditions several times. Once, I swear I looked at the mixture knob and the engine stumbled. :rofl:

I've flown the same airplane across about a 110-degree span of temperatures... And most of the time it's toward the warmer end of that span. I think that when it gets REALLY cold, full rich may even be lean of peak.

For an Alaskan airplane, they'd set the rich mixture differently, which is why they do just fine in colder temps up there while we have temperature rules they'd scoff at.
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I can't say that I agree with anything you said here. Plenty of airplanes get flown into this temperature range with no ill effects.

I have to assume that you statement regarding the mixture is because the more dense air will cause the mixture to become too lean? If this is the case, then none of us would ever be able to get to altitude.
 
flyingmoose said:
I can't say that I agree with anything you said here. Plenty of airplanes get flown into this temperature range with no ill effects.
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And I believe that their mixtures are set (by the A&P's) to be richer than the average CONUS bird.

I have to assume that you statement regarding the mixture is because the more dense air will cause the mixture to become too lean? If this is the case, then none of us would ever be able to get to altitude.
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As you climb, the air gets LESS dense and your mixture gets RICHER. You then respond by leaning it out via the handy red knob on the panel.

As it gets colder, the air gets denser, and your mixture gets leaner. If your red knob is still hitting the panel, you're not going to be able to get it any richer.
 
flyingcheesehead said:
And I believe that their mixtures are set (by the A&P's) to be richer than the average CONUS bird.
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Can you show me anything to prove this?
I'm not saying its not true, only that I have been doing this quite a while and have never heard that. Maybe I can learn something today. I have also flown in some dang cold weather and never had an issue with mixture control. I have also look at all the POH's I have around and I am not able to find any cold limits. I remember there was a cold limit in a jet I used to fly, but it was so cold that it was unlikely to ever be hit.
 
It may well be that the mixture gets 'too lean' at -30F, but with the amount of cooling available, your head temps are never going to get into a range worth worrying about.
 
flyingmoose said:
Can you show me anything to prove this?
I'm not saying its not true, only that I have been doing this quite a while and have never heard that. Maybe I can learn something today.
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Simply experience from flying in extremely cold conditions - Cold enough that if I moved the mixture control even 1/4" the engine started to die. And I'm not talking a one-time occurrence, it's happened to me several times in extremely cold conditions. Still, in AK they can fly the same birds in conditions probably 40ºF colder than I've flown, in which case I don't think the engine in my midwest-based birds would support combustion due to the over-lean mixture.

Also, the engine does run better in extreme cold if you add carb heat, which heats the air and richens up the mixture. That would also indicate that my theory is correct.

weilke said:
It may well be that the mixture gets 'too lean' at -30F, but with the amount of cooling available, your head temps are never going to get into a range worth worrying about.
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I'm not worried about temps at all - It's way too cold to get anywhere near that. Even the other day on the Mooney, which has the winter kit installed, I couldn't get things as warm as I wanted at much warmer temps than I'm talking about here. At one point, I hung the gear, flaps, and speed brakes out and stayed at cruise power and still had CHT's below 300ºF and oil temp not quite into the bottom of the green range.

What I'm talking about is a mixture that's too lean to support reliable combustion.
 
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