While we have had an easy winter so far (thank you El Nino) here in the mid-west, the days are starting to get colder, and I’m sure we will have snow on the horizon. Even though our temperatures have been mild, it is always best to take the time to do what you can to protect your aircraft. Winter presents a number of unique challenges to an aircraft’s system. Each aircraft has its own specific requirements, but here are a few general tips to keep in mind.
Starting a cold aircraft engine without preheating can cause as much piston wear as 500 hours of normal operation. In addition to damaging the engine, failure to preheat can lead to minor amounts of abnormal wear to internal engine parts and eventually to reduced engine performance and shortened TBO time.
Airplane parts are expensive, so it’s a good idea to preheat your aircraft before you head out for a flight on the next cold winter day. But how should you preheat your aircraft? Three of the most popular methods are: forced-air preheaters, electric heaters, and a heated hangar.
If you ask for a preheat at your FBO, chances are they’ll use a forced-air preheater. While they are able to kick out quite a bit of heat, they don’t evenly heat the engine. When engine parts heat up at different temperatures, they expand or contract at different rates. This can lead to more wear-and-tear on startup.
An even better way to preheat your aircraft is with an electric heating system. The E-Z heat aircraft engine heater makes for a much more reliable start in the cold weather. This preheater heats the entire engine through convection/conduction with a flexible heating element that is installed on the engine. Once plugged-in, the system will monitor itself with the built-in thermostat which eliminates the worry of oil carbonization.
Want to make preheating your aircraft even easier? Purchase the CS-100 from Cell Switch. Cell Switch utilizes existing cellular networks to allow users to remotely control any device, such as an engine preheater, by simply plugging the device into the Cell Switch module. You can activate the preheater by calling the module using an authorized phone number.
Pulling your aircraft into a heated hangar is one of the best preheating options because everything warms up to the same temperature. While this is an ideal option, heated hangar space is hard to find, and it can take up to 12 hours for everything to reach hangar temperature.
So, when should you preheat your aircraft? Usually when the temp drops below 32F, you should preheat your aircraft. Better yet, if you need a winter coat to pre-flight your aircraft, it could probably use a preheat.
Say No to CO
The most common heating system in general aviation aircraft heats air by passing it through a shroud on the exhaust system before venting the heated air to the cabin. It is important that this type of system be thoroughly inspected to eliminate the possibility of carbon monoxide entering the cabin area.
Because of the risk of carbon monoxide in a closed cockpit and the fact that it is not readily detectable, purchasing a carbon monoxide detector is ideal.
Even if an aircraft has a gas powered heating system such as a Janitrol heater, or even an I-Series Hartzell aircraft cabin heater which can replace the OEM installed Janitrol heaters, you still need to ensure the heater is in proper working order.
To Replace, Or Not To Replace
To move air from one area to another, flexible ducting is used throughout most of the heater systems. Typically, you will find Scat tubing between the ram air port and muffler shroud and the shroud and the blending valve. Inside the cockpit, this ducting is located between the central duct on the firewall and various heater outlets in the defroster.
Since heater performance is dependent on getting all the heated air to the cabin, leaks in any of these ducts will impair performance, sometimes drastically, since the output is minimal to start with. To prevent this problem, make sure to thoroughly inspect the condition of the tubing, especially at the endpoints where clamped. Remove the hose at the muffler shroud and visually inspect the interior. Tears, splitting, unraveling, and worn-through spots are all reasons to replace the tubing.
It’s That Wintertime Oil
Ensure the correct grade of engine oil is installed. In addition, make sure to use the recommended grade of lubricant to grease the aircraft. Oils and greases that are great for summer operation could have a detrimental effect in the wintertime. Always follow manufacturer recommendations for lubrication.
Well, Aren’t You Special?
Batteries require special care during cold weather. Wet cell batteries should be kept fully charged or removed from the aircraft when an aircraft is kept parked outside to prevent loss of power caused by cold temperatures and the possibility of freezing. If a battery is discharged because of hard starting conditions, don’t allow it to remain in a discharged state. Ensure that it is charged immediately to help avoid any damage to the battery.
Do not use a high-amperage, fast charging battery charger because it can damage an aircraft battery. Use a battery charger like the BatteryMINDer, an aviation specific battery charger, which features a temperature compensating sensor to ensure that the battery can be safely charged and maintained for extended periods of time in extreme temperatures. Without this type of temperature sensing, batteries will be undercharged in colder temperatures.
During the winter, perform the hydrometer test once a month and keep an eye on fluid levels. If the battery is two or more years old, it will probably need to be replaced.
Cold temperatures cause pressure in tires and struts to decrease. Low tire pressure can cause a lot of problems, including reduced take-off performance, slippage, blow-out on landing, and increased tire wear. Make sure to check your tires regularly.
Tires are not the only pressures that matter in winter. Nitrogen-charged oleo struts can change height with temperature and should be adjusted based on the temperatures. It is also important to keep the exposed chrome strut piston as clean as possible to reduce wear and fluid leakage. If the seal in the oleo strut is deteriorated, the strut will not hold air pressure and must be replaced.
Everything is more difficult when it’s cold outside, but regardless of the conditions, make sure that inspections and maintenance are done right. Winter flying can be safe. But the problems of freezing temperatures, conditions such as ice and snow, and shorter periods of daylight combine to make a pilot’s job more demanding and the risks greater during this period of the year. A safe pilot tries to reduce those risks through planning. Proper maintenance, flight planning, and a good pre-flight are the best ways to reduce the risks of winter.
What steps do you take when preparing your aircraft for winter? Comment below and let us know.
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