Cold Weather Operations… What, When & How of Using Engine Preheat

It’s that time of year again that we need special preparation for winter and cold weather operations. Over the years, we have become more educated on the importance of properly preheating an aircraft engine prior to starting in the cold. The need to preheat goes beyond just the ability to start the cold engine; it is now known that proper engine preheat enables safer winter operations and helps save on fuel costs with shorter run-up times.

Here are some cold temperature engine startup tips from the folks at Tanis Aircraft Products in Eden Prairie, Minnesota:

What are the benefits of engine preheat?

Preheating reduces engine damage caused by cold starts. Cold starting and inadequate preheating can and has caused 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 the 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 prepared state, reduce the wear, and reduce the run-up times during cold weather operations.

How do I know when engine preheat is required?

Always refer to the engine manufacturer’s recommendation. (Refer to 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, Tanis suggests 6 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), Tanis says that you can leave it plugged in continuously.  Tanis Preheat Systems heat the entire engine, which Tanis feels is the intent of SIL 03-1, and Tanis does 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 the Tanis system on a 4-cylinder engine is approximately 250 watts, and approximately 500 watts for a 6-cylinder engine. A 16-plus gauge extension cord is adequate.

For over 37 years, Tanis Aircraft Products has manufactured customized preheat and maintenance solutions for many different aircraft and helicopter applications; single, multi and turbo prop. Tanis Aircraft Preheat Systems completely heat soak the engine the way manufactures 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 (

This entry was posted in February/March 2013, Products & Services, Sections and tagged , , , , , . Bookmark the permalink.

Leave a Reply