Bits and Pieces
Cold Weather Operations - What, When, and How of Using Engine Preheat
Play it safe - plug it in
Cold wings, warm engine
Example of a Tanis preheating setup
By Christine Wetherell, Tanis Aircraft
It's that time of year again to start thinking about preparing for winter and cold weather operations. Over the years, we have become more educated about the importance of properly preheating an aircraft engine prior to attempting a cold start. The need to preheat goes beyond just the ability to start the cold engine; it is known that proper engine preheat enables safer winter operations, helps save on fuel costs with shorter run-up times, and avoids unnecessary engine wear. The folks at Tanis Aircraft Products, Eden Prairie, Minnesota, provided us with the following information:
What are the benefits of engine preheat?
- Preheating reduces the damage caused by cold starts.
- Cold starting and inadequate preheating can cause engine failures.
- Often, preheating is the only way to get a cold engine started. Cold fuel doesn't vaporize well, and spark plugs tend to frost.
- Easier starting increases the longevity of your starter and battery.
- Continental Service Information Letter SIL 03-1 states: "Failure to properly preheat a cold-soaked engine may result in oil congealing within the engine, oil hoses, and oil cooler with subsequent loss of oil flow, possible internal damage to the engine, and subsequent engine failure."
- All engines have wear and corrosion issues; even the best maintained engines will have problems eventually. The main goal of preheating is to keep aircraft in a prepared state, reduce the wear, and reduce the run-up times in cold weather operations.
How do I know when engine preheat is required?
- Always refer to the engine manufacturer's recommendation.
- Here are some examples (www.TanisAircraft.com/TechData.aspx):
- On cold weather operation-engine preheating, Continental Service Information Letter SIL 03-1 states: "Preheating is required whenever the engine has been exposed to temperatures at or below 20°F/-7°C (wind chill factor) for a period of two hours or more."
- Lycoming Service Instruction No. 1505: "The use of preheat will facilitate starting during cold weather, and is required when the engine has been allowed to drop to temps below +10°F/-12°C."
- Also refer to your POH/AFM for cold weather operations information specific to your aircraft.
How long do I need to preheat with a Tanis System?
To fully heat a cold-soaked engine for max benefits, we suggest 4 to 5 hours before flight.
Can I leave the Tanis heater plugged in continuously during the cold weather months?
Continental does not recommend leaving a preheat system on for more than 24 hours. However, if you are flying on a regular basis (once a week or more) you can leave it plugged in continuously. Tanis Preheat Systems heat the entire engine, which we feel is the intent of the SIL 03-1, and we do not sell or endorse systems that heat only the oil.
Can I use a portable generator to power the preheat system?
Yes - as long as it has adequate capacity. Wattage required will depend on the system installed.
What are the power requirements?
A Tanis Preheat System installed on an aircraft uses a ground/shore alternating current (AC) power source while in standby status, and is not used in flight. Systems are available in 115-volt and 230-volt configurations. Power draw varies depending on the system. Typical power consumption for our system on a four-cylinder engine is approximately 250 watts; for a six-cylinder engine it is approximately 500 watts. A 16-plus gauge extension cord is adequate.
For more than 37 years, Tanis Aircraft Products has manufactured customized preheat and maintenance solutions for many different aircraft and helicopter applications: single, multi, and turboprop. Tanis supports the aviation industry with products that make winter operations safer, prolong engine life, and save money. Tanis Preheat Systems completely heat-soak the engine the way manufacturers recommend. All systems include an oil sump heating element, cylinder heat heating elements, and wiring harness/installation hardware. Helicopter preheat systems typically include heating elements for the engine, main gear box, accessory gear box, FCU, hydraulic tanks, oil coolers, and tail rotors. Battery preheat systems are available and sold separately.
For more information, visit www.TanisAircraft.com.