Maintainers Corner: Winter Operations
Well it’s that time again. Winter is just around the corner and the float season has come to an end except for a few hard-core floaters. I’d like to take this opportunity to discuss winter operations, mainly fuel and pre-heating.
As most of us already know, daytime heating and night time cooling causes condensation. So in regards to the fuel tanks it’s a good idea to keep them full or as near full as possible to limit the amount of condensation build up. Fuel sump drains can be lubricated with something as common as WD-40 to prevent valve freeze up.
Engine pre-heating is a must in cold weather. Just as you would plug in your car, you should pre-heat your aircraft engine.
There are different methods and manufacturers out there that supply a variety of engine pre-heat systems. The most common one that seems to be used is the Canadian Tire “Buddy” heater. Although pretty effective at heating the outside of the engine, it does not heat the inside of the engine. Be it in a hangar or outside with covers, your aircraft engine is a block of cold or frozen metal, unless the hangar is heated.
Pre-heating times will vary, depending on which system you use. For example:
at -15C, a “Hot Pad” system (such as E-Z HEAT, REIFF or TANIS) with cylinder heat will require a pre-heat time of approximately 30-45 minutes (manufacturers list times for temperatures);
a “Buddy” heater inside a hangar at -15C will require approximately 2 - 2 ½ hours; and
a “Buddy” heater outside with engine covers at -15C will require approximately 3½ - 4 hrs depending on how snug your engine cover is.
NOTE: It is a good practice is to check the oil when pre-heating; if it is thick then there is probably not enough heat.
Once the engine is running and until the engine is up to operating temperature, the moisture content in the engine is still present. It takes a good 1 - 1½ hours of flying in winter to evaporate the moisture content at normal operating temperatures. Some engines may heat up faster and burn the moisture off more quickly, and some will take longer depending on outside air temperature and installation of winter kits etc. Nevertheless, a minimum of 1 hour of actual flying is usually required to burn off the moisture.
Remember, treat your aircraft like you would a brand new vehicle, possibly even better because as we all know, when trouble happens in the air, you can’t just pull over to the side of the road. Happy Winter Ops!
(This information provided courtesy of Kori Ibey of Maximum North Aviation)