Its starting to get cold out there, so this is a great opportunity to remind ourselves of some factors for flying when its cold. Here is a pretty good overview from the FAA:
Some important points:
On Preflight, be sure that the airplane is pre heated. As many of us know, aircraft engines are pretty hard to start when they are really cold, and dont like to run once started if cold. Another less obvious but much more serious problem with not pre heating is that the engine oil is not warm and viscous, instead it will be thick which doesnt help lubrication in any way. Also, check the crankcase breather tube on your preflight? Whats this you ask? The crankcase breather tube is a simple tube that allow the crankcase to vent, so that pressure does not build up inside. On preflight, you should see a small pile of frozen material under the crankcase breather. This means that it is clear and allowing the crankcase to drain. If the ground is clear, and the airplane has not been moved since shutdown, that would be an indication that the crankcase breather tube is plugged. In this event, instead of venting the case, pressure will be allowed to build up inside. Eventually something will have to give, and usually that will be the main seal on the front of the engine where the crankshaft exits. Many NTSB reports have been generated from the ensuing oil loss and engine failure.
Carb heat usage in cold weather should also be revisited.
As you can see, at very low temperatures, the threat of carburetor icing reduces to nearly zero. In fact, below 10 degrees F there is no risk of carburetor icing at all. Using carburetor heat below these temperatures could actually CAUSE carburetor icing by warming the fuel/air mixture to a a temperature conducive to icing. I know of this happening in Cessna 150s. A friend managed to limp his 150 back to the airport with an iced up carburetor. The only way he was able to keep the engine running was to pump the throttle which broke some of the ice free of the venturi. Certainly not something we want to have to count on!
Dressing for flight is a third and very important aspect to winter flying. Any flight, regardless of the time of year, should be approached with the attitude that you will have to walk out of field somewhere. Dress appropriately. A nice warm coat, stocking hat, and gloves would be considered a minimum. Carrying food and other survival equipment is a great idea. The FAA article suggests a survival kit for winter flying. Also, check out Doug Ritter's website for a lot of info on survival.
Dressing for flight is a third and very important aspect to winter flying. Any flight, regardless of the time of year, should be approached with the attitude that you will have to walk out of field somewhere. Dress appropriately. A nice warm coat, stocking hat, and gloves would be considered a minimum. Carrying food and other survival equipment is a great idea. The FAA article suggests a survival kit for winter flying. Also, check out Doug Ritter's website for a lot of info on survival.
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