In general, what are the difference between summer and winter flying. I understand the air is heavier and such. What about engine settings. Do you set them a little leaner? I flew last Sunday, temp was high 40s. The glow starter that was working fine in warmer weather was not starting the engine. When we used another one it fired right up. Things like that.

Hi,
I live in london, and i go winter flying all the time, the main drawbacks
is that it is cold! esspecailly when you have to do a repair. As the the engine setttings.
What I normally do is close the needle valve, open it 2 + 1/2 turns, and start the engine,
then I tune it to optimum level.

Cheers
Volkan

When the air is colder, it is denser. This means that for a given unit volume of air, there are more air molecules. So, to keep your air-fuel mixture the same, you want to richen a bit. More air means you need more fuel to maintain the ratio of air to fuel. This might seem counter-intuitive as one might reason that since engines run hotter when leaned out, that would counter act the colder temperatures- this is NOT the case. Hope that helps.

Marl

It depends how low a temperature you intend to fly in, yep you might need to richen up a click or two.

You'll find that engines need more winding on the electric starter before they start. So keep your field battery topped up. It could be worth using a fuel with more nitro content, say moving up from 5% to 10%. Some folks use a splash of petrol (lighter fluid) down the carb to get things started, not needed to do this my self.

Make sure you give your engine a good blast of full throttle just before you take off to get it warmed up properly. You don't want a dead stick on take off.

Also keep an eye on your flight packs too as batteries tend to loose capacity quicker in the cold.

As for the actually flying it is nicer when the air is colder. It feels more like the plane is on rails and you have more bite with your prop.

I find that keeping my fingers warm is the hardest part. I don't like gloves when flying as they take away too much feel and my flying suffers. So I tend only to fly for a few minutes at a time and then thaw out my hands. I'm tempted to try a tranny muff.

Nick

Yes, you generally have to richen the mixture. On one of my four strokes which is usually flown in 70 to 80 degree temps, I had to richen the needle almost a full turn when flying in temps under 30 degrees.

Right too about your batteries. Keep them well charged; that's probably why your glow ignitor didn't work. (Did you charge it the night before?)
Dennis-

There are some risks to your ABC/N engines during winter operation.

One risk to an ABC/N powerplant in cold weather is exactly the same as the risk to a new ABC/N during break-in if it is run too rich -- the cylinder temp is not quickly raised to an adequate level & the piston-cyl fit at the top is quickly degraded -- this can occur in a fully broken-in engine in cold weather & the danger is greatly increased for a brand new engine. The consequence of such damage is that the engine's life will be significantly shortened. To avoid this type of damage, the upper cylinder & cyl head area should be partially shrouded to limit cooling, & thus permit operation at appropriate temps. This type of damage is not usually apparent for some time -- the engine seems to run just fine. However, its usefull lifetime will be shorter, as it is already on the way to wearing out. Those of you who run your engines during winter without carefull preparation, & think that they are OK, may very well be fooling yourselves -- the damage is probably there already, & will become apparent in the future. The colder the temp, the greater the damage.

The other risk comes from over-lean mixtures & this danger is greatly amplified at low temperatures. The resulting damage will very quicky ruin an engine -- one or two runs will do it. The "tuning band" becomes very narrow at low temps -- too rich & you accelerate the wear that is like an improper break-in -- too lean & you kill it much more quickly. The low air temp makes ignition more irregular & engines don't want to run well at a safe, but not overly rich mixture, unless some means is employed to raise cyl temps (shrouding, for example), which leads some modellers to lean out the engine a bit more until it runs well -- very dangerous practice.

For more information see the Oct 2003 issue of Fly RC magazine

_________________
Never take life seriously -- nobody gets out alive

get some skis, go to her, i was just out, had to get my dad to throw it for me, in the backyard, didnt even go to the field, i learned how to land under an electric fense and flip over when i hit the snow, i dont have skis yet, lol.

We have -6celcius here today, that would be about 20Fahrenheit I guess.
Going to fly tomorrow, the plan is warm clothes, fishing gloves "without fingers" and thermos with hot coffee.

We have -6celcius here today, that would be about 20Fahrenheit I guess.
Going to fly tomorrow, the plan is warm clothes, fishing gloves "without fingers" and thermos flask with hot coffee.

Hey guys! Thanks for the info and advice. I was 180 degrees on the wrong side of the fuel setting. The guy that helped me get started told me to adjust to maximum RPM and then back it off about 300 RPM. He had a tach. Does that sound right? The shrouding sounds interesting and logical. The two planes that I fly now both have "open" engine mounts, (no cowling). That would make shrouding more difficult. How would you suggest to do that?
Thanks again for the info..............

I wrap aluminum foil around the top of the cyl. , held on with a rubber band. High nitro helps too. I use 25%. Heating up the cyl with your car's exhaust helps the ugly ones to start.

I'm kind of lucky. My place of employment has an engineering garage with a 24' ceiling and a closed down former production area with a 28' ceiling. Great for indoor rubber free flight and maybe some smaller indoor R/C or electric control line or round-the-pole. Of course for my AMA all weather flyer patch, currently in year 13, I do go out either to the club field or to the small park across the street monthly. Somehow, counting indoor flying strikes me as cheating.My Fox BB 25s run beautifly outdoors down to about 10 degrees F. Below that, I don't operate so well.

id second the aluminum foil on the upper cylinder . it will help in really cold weatherespecially if you do a lot of idle/approaches etc.. keep the batteries & plane reasonably warm until ready to fly.using mostly synthetic will help as castor really gets congealed in cold weather.you may want to check out getting some large sheets of heavy clear plastic at hardware store to put up around the lean to or at least a couple tall posts with plastic as a wind break. even a light breeze in winter is very chilly.

Keep the castor-based lubricant. You are relying on lubricant film-strength & it is very much more important at low temps. Castor has noticeably greater film strength than syn at low temps. If the oil was being circulated, as it is in a car, then the syn would be the choice because it will flow more easily & circulate quickly, but in a 2 stroke you are relying on lube in solution. The weaker film strength of the syn lube puts the 2-stroke engine at greater risk in cold weather.

At which temperature would you use the Aluminum foil on the head and cylinder?

Thanks much,
Ryan

Overcoming problems flying in winter?

Move to Australia!