Froze oil Cooler -38C

[aaronk25]

Came back from Daytona Beach yesterday up to wonderful frozen MN.  Ended up flying about 9 hours and going though MS, then north to get around the front that crossed the whole US.  Consequently I ended up getting to Rochester MN just before 11PM, and had my share of trouble.  

 

Was cruising at 10K full speed ahead 2700rpm, indicating about 145kts- so 160-162kts true and upon reaching Southern Iowa the temps were -27C, then over Central Iowa -35C, Northern IA -38C and thats when the fun started.  Oil temp went from 163 to 220 in about 7 mins.  I guess the 20w-50w phillips oil was no match for a super cold oil cooler.

 

I removed the homemade air flow restrictor I made to block about 1/2 of the air going into the cooler before my trip to the south because when cruising at 10K the temps have to be colder than 3C or the oil temps start working there way up to 210 and given I was going to be in a warmer climate for part of the trip I elected to delete it.

 

The only reason I made a oil cooler airflow restrictor is to keep temps warmer than 163F to burn of moisture, not to keep a oil cooler from freezing.  I made a stop in Columbia MO for fuel and it was 13f and gusting 30kts and dark so I didn't "feel" like freezing my hands to install it.  I should have.  

 

I will admit I was kinda chuckling about the recent thread about how cold of temps to fly in and thought people were being over cautious, but looking and considering the following I now would not have made the flight.  I continue to become more conservative with decision making.

 

-Any mechanical failures that would have created the need to land off airport could have been deadly. -40 windchills.  (especially given one of the pax only had a sweatshirt DUMB)

-If a heater hose would have come off the windows would have immediately frosted over making landing difficult.

-autopilot had hard time controlling pitch due to stiff trim wheels.  Remember all that gear is in the back of the plane where its cold.  

-fuel could have froze,I pulled the gasolator pin about every 15 Mins as a precaution.

-Conditions on the ground were 1-2miles vis due to gusty winds blowing snow.

 

 

 

All in all my attitude has changed about winter flight. -25C is now my cut off. 

 

Here are some pics---the JPI is just before the cooler froze. 

[Marauder]

Well Aaron, you just reinforced my decision about moving south. Ironic that you should mention survival gear since I just updated mine. I still carry a survival pack with me applicable to both summer and winter ops. When I was up in New York over Thanksgiving I showed it to my brother who had a good laugh when he found the machete.

[Matt Michael]

Awesome post.

[pinerunner]

Check this site out.   

 

www.oilcoolers.com/article_oil_cooler_woes.asp

 

It shows what can happen at very low temperatures as the oil in the cooler gets VERY viscous. It makes me feel very cautious about winter flying.

[jackn]

Could you post some pics or info on your homemade airflow blocker? I need to do something to keep oil temps higher.

[Sable1]

Hey Aaron - welcome back!  (you couldn't stay in FL for a couple of more days??)

Still thinking about the $100 hamburger run this week...  (I think you'd be the only one there)

Seriously - glad everything worked out ok.  Thanks for sharing.  Given the recent posts on the cold weather ops, I have certainly been giving more thought to personal minimums.  Ditching in a cornfield at 11pm with -20+ F temps (not to mention the windchill) is not my idea of a good time.  Even landing at a remote airport in the middle of nowhere can still be dangerous.

Thanks for sharing!

Tedd

[Danb]

This post really makes me sure I should consider survival gear, I've usually been ready for cross water problems. Am I dumb. Happy your safe

[takair]

Thanks for the write up. I would suspect the old Mooneys with the oil cooler out front might be even more susceptible. Curious about pulling the gascolator pin. I would be worried about it getting stuck (or frozen) open and not knowing it. I would think the normal fuel flow through there does the same thing. Maybe I am missing something?

[aviatoreb]

 

-Any mechanical failures that would have created the need to land off airport could have been deadly. -40 windchills.  (especially given one of the pax only had a sweatshirt DUMB)

-If a heater hose would have come off the windows would have immediately frosted over making landing difficult.

-autopilot had hard time controlling pitch due to stiff trim wheels.  Remember all that gear is in the back of the plane where its cold.  

-fuel could have froze,I pulled the gasolator pin about every 15 Mins as a precaution.

-Conditions on the ground were 1-2miles vis due to gusty winds blowing snow.

 

The dangers of an off field landing, even a uneventful and safe off field landing in a nice cornfield 2 miles from a nice town, being potentially fatal at -40F of windchill...that is what I was talking about in that other thread on this topic I started.  That's too cold.  (BTW roughly -40F=-40C).  That like flying over open water - a real problem to deal with.  I do carry two sleeping bags, and then my cowl cover and then survival gear, and so forth.  But lets say I would rather not be using that stuff at -40F.  There is one mooney pilot on here from the great white Canadian North who flies with a gun for the polar bears.

 

And as I said in that other thread, strange things happen to the equipment in extreme colds.

 

I have been running prist lately in winter months, since it does not take -40 to freeze water in your tanks to cause a problem.  I have been adding prist to my fuel starting in mid fall starting this very year.

 

BTW folks - we hit 50F today!!!!  After -25F (no wind ) last Thursday morning.  Then back down to 5F tonight.

 

I'm so glad you are ok Aaron.  Thanks for sharing.

[David Brown]

The freezing point for Avgas is -50dC or -58dF, and now I understand why   Perhaps it would have been warmer down here this last week!

 

Aluminium Foil Tape is the answer to coolers, and it tends not to leave the cooler all sticky and gooey to collect dirt and grass etc later in Summer.

 

Sorry you guys call it Aluminum Foil. 

[scottfromiowa]

Glad that worked out O.K. Aaron...pump the brakes man...I didn't even like driving today (overnight in Mankato) -15 on the thermometer is not fun to see....Yes, that is killer cold if something unusual happens. Be safe man.

[aviatoreb]

The freezing point for Avgas is -50dC or -58dF, and now I understand why   Perhaps it would have been warmer down here this last week!

 

Aluminium Foil Tape is the answer to coolers, and it tends not to leave the cooler all sticky and gooey to collect dirt and grass etc later in Summer.

 

Sorry you guys call it Aluminum Foil. 

 

David, I read somewhere that there is a heat wave "this summer" in Australia right now hitting 120F this week?

 

Now - the worry with avgas is not that the fuel will freeze - its that if there is any water in the fuel, that it separates as it is supposed to, but then that water freezes and blocks the fuel intake.  This can be a problem at temps much warmer than -50C (but still very cold temps).  All I know is the Canadian Mounties use prist, ... and so do I.  Eh.

[mike_elliott]

Glad you made it back, safely, Aaron. In hindsight, maybe you should have just stayed here until after the Mooney Summit  . A whole lot of people from up north are thinking that way. That said, the temps here are ridiculously low this morning 35 deg, but that wont last long. House closings are way up this week. See you in a month!

[Marauder]

Glad you made it back, safely, Aaron. In hindsight, maybe you should have just stayed here until after the Mooney Summit . A whole lot of people from up north are thinking that way. That said, the temps here are ridiculously low this morning 35 deg, but that wont last long. House closings are way up this week. See you in a month!

I'll take your 35! It was -3 at my house this morning. It NEVER goes below 0 around here...

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[David Brown]

Erik,

 

PRIST is a good idea indeed.

 

We have more problem with vapour lock at the moment.

 

Putting down in the outback might not be much more survivable and maybe a quick frozen death is better??? 102dF might have happened in one or two spots and I think 110dF was a bit more common, and plenty of places over 100dF.

 

I do not have to shovel sunshine off my driveway though.

 

You guys be careful over there!

[jlunseth]

I would not pull the gascolator in the air.  They have a propensity to stick.  Open.  It has only happened to me on the ground, and that was probably because I pushed the gascolator from below with the cup pin.  I managed to get it shut, but that would have been impossible in the air.  The fuel flow is pretty impressive.  A couple of gallons drained out in about a minute. 

 

Fuel is flowing through the gascolator in flight.  Freezing should not be an issue.  But if you are concerned about fuel freezing, put up to 3% isopropyl in the fuel.  Don't pull the gascolator though.

 

I mostly stay on the ground in the cold part of the winter.  It is just not that fun warming the airplane up and dealing with all the issues. 

 

We did have an engine out off field by two local instructors in a Mooney about 5 years ago.  The throttle stuck in a "throttled down" position so they could not make enough power to stay aloft or get to a field.  Uneventful.  Plane and crew were fine.   Landed in a snow covered field.

[BorealOne]

Give me -40 over those crazy Aussie temps (+50!!!) anyday. I can still remember waiting in queue for takeoff at Darwin Intl on December during the buildup--it was +45C and something like 100% humidity--it was like trying to fly in a sauna!

Fly safe folks, wherever you may be.

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