Bottom line is, Mother Nature makes all the rules, and Mother Nature always wins if you try and break those rules.

A big bore Continental or Lycoming holds about 3 gallons of oil. Just for fun, pour three gallons of oil in a metal gas can and stuff it in your deep freeze overnight. Next morning take your can out, and set it in front of your kerosene space heater, or whatever else you might want to heat it with. I guarantee you that you can get the outside of that can damn near red hot, and the outer layer of oil near boiling, but still have a big ball of frozen oil floating right in the middle.

I have watched guys, not heard rumors, but watched guys myself take off after piss-poor pre-heats, get in the air and make 180's right back to the ground with oil starvation engine failures. Culprit being frozen oil in the sumps.

Engines are expensive, and it's a good way to get killed.

MTV is so right. Slow and gentle on the heat. Get the best engine blanket you can buy (keep it in the airplane as an emergency sleeping bag too), and keep your gyros warm.

One of our Golden Rules in the Arctic was the colder it gets, the slower you move. And there's very good reason for that.

Gump

damn good advice, gump. here in idaho at about 5000', if u dont have
a hangar of some sort, bring it up slowly on the temps.
nothing wrong with a slow taxi, and a real slow take off roll, with lots
of time to retreat. use the longest runway available, if it don't look and
feel right while slowly applying power, abort! my 540 turbo is way cold-
blooded and does not like to be run hard when cold. same goes for
smaller mills. borrow a hangar the nite before if u can, and a blanket
with some sort of heat up the cowl flaps will help expedite your departure.

my hangar heat is set at 45 and stays almost 60, and am happy to loan
it to travelers for over-nite. can fit one more bird besides my 182.
if any of you should come this way in the winter, be sure to pm me
if you need to over-nite at no charge. frost and ice cold temps are
killers. have seen lots of rag-wing and others lost to goofy stunts
like gump describes....we cant all be livin' in all that heat in nevada
like gump! some of us require big SNOW to survive...!

jomac wrote:we cant all be livin' in all that heat in nevada
like gump! ...!

No heat in this place. The bunch of us from the Northern Nevada gang all live between 4,500 and 5,000+ feet MSL, and the rocks behind my house go up over 11,000 feet. It gets colder than shit over here. The weather in this place will mess you up as quick or quicker than what I experienced in Alaska.

Gump

So, if your preheat source is generally aimed at the sump, and the dipstick comes out all warm and slippery, do you guys consider that a sufficient measure of preheat?

Different engines will have different geometry, so specifically, how about an O-300A Continental?

You can definitely tell from the dipstick when the oil is NOT warm enough for start-up

-DP

jomac wrote:nothing wrong with a slow taxi, and a real slow take off roll, with lots
of time to retreat. use the longest runway available, if it don't look and
feel right while slowly applying power, abort!

I'd say that perhaps the takeoff roll is not the place to be making those decisions.

And yeah, N. Nevada is cold.

Denali,

Yes, checking the dipstick is a good place to start on checking the core temp.

Again, it's not rocket science. Get a good engine cover, which is AS important as a good engine pre-heater, and after you've heated for a while, let it soak with the cover on for a while.

As I noted, you can't put a time on this, cause there are just too many differences in engine design, and in what people call cold. It doesn't take nearly as long to pre-heat a little Lycoming when ambient temps are +20 as does a radial at -35.

Everts Air in Fairbanks plans on a full 12 hours of pre-heat on a cold soaked R-2800 on the DC-6 or C-46. That's with a Herman Nelson per engine. It just takes that long to heat that big mass.

I agree with Zane--pre-flight taxi and takeoff run is no place to find out whether your pre-heat was adequate. When you start that engine, there should be no doubt in your mind that it's warm enough. If there's some doubt-pre heat a while longer.

MTV

1SeventyZ wrote:

jomac wrote:nothing wrong with a slow taxi, and a real slow take off roll, with lots
of time to retreat. use the longest runway available, if it don't look and
feel right while slowly applying power, abort!

I'd say that perhaps the takeoff roll is not the place to be making those decisions.

Maybe on a 12,000 foot runway .

But really, just let the engine warm up for an extra 10-15 minutes at about 900-1000 RPM.

58Skylane wrote:But really, just let the engine warm up for an extra 10-15 minutes at about 900-1000 RPM.

No, that just gives you an extra 10-15 minutes of cold steel wearing off chunks of cold aluminum inside your engine, and a set of lead fouled plugs.

Gump

GumpAir wrote: Get the best engine blanket you can buy (keep it in the airplane as an emergency sleeping bag too)

Gump

A nice thick moving blanket from Home Depot works well when parked in a hangar. If parked outside, you will need a way to keep it from blowing away. I keep at least one in the plane all the time.

But now that I think about it, a purpose made engine blanket would be much better.

GumpAir wrote:

58Skylane wrote:But really, just let the engine warm up for an extra 10-15 minutes at about 900-1000 RPM.

No, that just gives you an extra 10-15 minutes of cold steel wearing off chunks of cold aluminum inside your engine, and a set of lead fouled plugs.

Gump

Ok, I maybe be wrong in my statment above. My POH says "the engine should be warmed up at approximately 800 RPM for at least three minutes in cold weather. The rest of the warm up time can be done while taxing to the take off position, preferably limiting RPM to 1200 RPM".

Your POH is assuming that your engine was properly pre-heated to start with.

Frankly, if it's REALLY cold, running the engine on the ground simply makes things worse, since you really aren't going to warm the engine up doing so.

That's not necessarily true of a radial, but on horizontally opposed engines, too much time on the ground isn't good for them.

MTV

Gump wrote:I have watched guys, not heard rumors, but watched guys myself take off after piss-poor pre-heats, get in the air and make 180's right back to the ground with oil starvation engine failures. Culprit being frozen oil in the sumps.

The author of "Last of the Bushpilots" decribes destroying his engine because of a crappy preheat that left his oil just as Gump described.

mtv wrote:Frankly, if it's REALLY cold, running the engine on the ground simply makes things worse, since you really aren't going to warm the engine up doing so.

Really? Dang...if its 40 degrees out I'll start the engine and let it idle at ~1000rpm till the temp starts to come up. So I shouldn't do that? A couple winters ago I got a special out of IDA, I was all preheated at it had soaked in but the engine was only bout 60 degrees...air temp was about 10. I had to hurry because the tower wanted me out of there ASAP if I was going to use the special. I fired up did my runup and took off all in about 5 minutes. By the time I was 200agl my temp was up to 120 and all was good...except I couldn't see anything So yeah the temp comes up real fast but I always thought it was best to let it warm up some before giving it much throttle.

whee wrote:The author of "Last of the Bushpilots" decribes destroying his engine because of a crappy preheat that left his oil just as Gump described.

Bud and Martha wandered up to the Arctic in the 40's and learned the hard way how to maintain equipment in those weather extremes. Global Warming hysteria aside, nothing has changed, and you have to take the same steps to function up there as they did back then.

Village electricity has made life considerably easier in a lot of areas, but it still doesn't hurt to know the old ways, and be able to get by self contained. And just as important, is understanding the reasons and the science behind why you do things with airplanes in very regimented ways in extreme cold temps. Takes a lot of discipline.

Gump

To summarize the problem for people like me who had never previously considered consequences as severe as GumpAir described:

1) An engine's lubrication system depends on the oil being circulated to the places it's needed most. Without circulation, there is no lubrication.

2) Cold or frozen oil is too thick (or solid if cold enough) to be circulated and distributed to the crucial areas that need lubrication.

3) If started cold, or not pre-heated thoroughly enough, there is little or no oil available to be pumped to high-wear areas.

I only brought up what Bud wrote because he decribes pretty well how he preheated, what happined and that he'd never preheat like that again.

Zane,

Please re-read my post. I used the term "REALLY cold" with the emphasis added.

So, let me get this straight---you consider +40 F to be REALLY cold???

MTV

I'm guessing you were referring to me not Zane. I just took what you said as running an engine on the ground to warm it up is worse than taking off with a preheated but not yet up to operating temp engine. Sure, it won't warm all the way to operating temp on the ground but is seems that running on the ground for 10 min wouldn't be a bad thing. I dont have a preheater so I usually use a propane heater. Once I get a indication on the oil temp guage I take the heat off and let is sit for a while. By the time I start up, the temp guage has cooled off some so I run for a while on the gound till I get a good temp reading. I don't like running a luke-warm engine at high power.

Oops, yep, there I go again poking at the moderator of this here site in error....

At +40 degrees, I don't even bother to pre-heat. It can't hurt, but to me it's not worth the hassle, and those engines start and run fine at those temps.

Running an engine on the ground at VERY cold temperatures actually can cause more problems than it fixes. Once you take that engine cover off at -30, you're into a cooling off process, not a warming up process.

Running an engine for ten minutes on the ground in mild but cool temps like you describe isn't going to hurt anything and is probably a good plan.

Again, we all have our different perspectives of what constitutes "cold". Mine are sorta warped from living in Fairbanks for a lot of years, and working north of there most days.

MTV

My articulation of the primary problem was more related to Gump's story about the guys in Alaska taking off with sumps full of frozen yogurt. That's the extreme scenario.

If the oil flows well, even down to 32 F, there isn't a problem. I just wanted to make sure we're on the same page with the primary concern here.

well said -40 an 40 are totally different just me but flying at -40 is going to break more than engine i would think .