Why is it so important to preheat aircraft piston engines? According to aircraft engine manufacturers, the friction caused by starting a cold engine causes the same wear as 500 hours of run time. It’s critical to preheat every engine, from 4 cylinders to General Electric’s gigantic GE90 and everything in between.
This article explores the latest innovations in aircraft preheaters, their advantages, disadvantages, and provides information on preheating methods.
Background Information On Aircraft Engine Preheating
Preheating uses an external heat source to increase the aircraft’s engine and oil sump to its optimal running temperature before starting. Preheating helps prevent potential damage to bearings, pistons, and crankshaft caused by cold starts.
Cold temperatures cause crankshaft bearings to shrink, leaving less space for lubricating oil. Less oil means high bearing wear or even a “spun bearing,” leading to a catastrophic failure.
Benefits of an Aircraft Preheater
There are two primary benefits to preheating piston aircraft engines. It thins the oil to help protect the engine from the first crank and keeps the crankcase and engine parts at a uniform temperature.
Preheating provides a range of benefits, including:
- Reduces engine wear, increasing engine life.
- Starts faster and decreases the chance of frosting the spark plugs.
- Cuts the run-up time and saves fuel.
- Prevents cylinder scoring leading to a seized piston.
- Ensures immediate and proper oil flow.
Engine manufacturers mandate preheating because it improves the engine’s performance, especially at takeoff.
When Should You Preheat an Aircraft Engine?
Aircraft engine manufacturer Continental recommends preheating when an engine has sat in outside temperatures of 20°F (-6.7°C) or lower for more than 2 hours. Another manufacturer, Lycoming, instructs owners to preheat anytime the engine is at 10°F (-12.2°C) or colder.
Proper preheating is critical to ensure the engine is warm and at proper clearance before takeoff. There are a variety of preheating methods. Some have been around for decades.
Traditional Engine Preheating Methods
Traditionally, aircraft owners have relied on various methods to preheat their engines, including the following:
- Forced Air – Electric: These systems use an electric heater and a fan to blow hot air into the engine compartment.
- Forced Air – Propane: Combustion heaters burn propane (sometimes gasoline or diesel) to produce heated air, which a fan blows into the engine compartment.
- Engine Block Heaters: Electric engine block heaters are installed directly into the engine block and heat the engine directly using multiple heading pads connected to a wiring harness.
- Oil Pan or Dipstick Heaters: Electric oil pan heaters warm the oil in the engine by directly inserting it into the dipstick opening or installed on the oil pan.
Each preheating method has its advantages and disadvantages. The best method for a particular aircraft depends on several factors, such as the climate, the type of engine, and the availability of power sources.
Innovative Aircraft Engine Preheating Methods
In recent years, there have been significant advancements in aircraft preheating technology. One such innovation is heated blankets designed explicitly as an aircraft engine heater. They also have self-contained thermostats to prevent overheating like industrial thermal loops. Read all about the thermal loop here.
- Aircraft heating blankets: The blankets are electrically powered and cover the engine compartment or nacelle, keeping the exterior ice-free and the engine warm. Aircraft heating blankets can withstand engine-generated heat after a flight. They are made of high-quality, fire-resistant materials and are easy to install and remove. Overall, heating blankets are safe, reliable, and cost-effective for preheating aircraft engines.
- Wi-Fi Enabled Switching: While not technically a preheater, remote switches save time by allowing pilots to switch on installed preheaters hours before arriving at the airport. Switchbox is one brand of remote-operated control device operated by a cellphone app.
It’s important to note that while these methods may offer advantages in certain situations, traditional preheating methods are still widely used and effective. The method chosen depends on the specific needs of the aircraft.
Advantages and Disadvantages of Different Preheating Options
Each preheating option comes with its pros and cons.
| Preheating Method | Advantages | Disadvantages |
| Traditional Engine Preheating Methods | ||
| Forced air – Electric | Fast and efficient, it can heat an entire engine. | You must store equipment, and it requires electrical power. |
| Forced Air – Propane | Rapid thaw time. High heat. | Requires propane, tank storage, and electrical outlet. Open flame hazards. |
| Engine Block Heaters | Heats the entire engine block. | Need an electrical outlet. Requires professional installation. Long warm-up time. |
| Oil Pan or Dipstick Heaters | Easy to install, heats oil directly. | Need an electrical outlet. Only heats the oil, not the entire engine. |
| Innovative Aircraft Engine Preheating Methods | ||
| Aircraft Heating Blankets | Portable and easy to use with different aircraft. | Only heats specific aircraft parts, which may not be suitable for extremely cold temperatures. |
Most aircraft engine preheaters require access to power outlets, which may not always be available in all locations.
Which Method is Best for Your Aircraft?
If you keep your plane outside, snow removal is a problem. Using heating blankets on the wings and the ground prevents snow removal mistakes. Powerblanket’s Extra-Hot line of thawing and heating blankets is an all-in-one heating solution that can preheat aircraft, providing superior protection and rapid thaw capability.
Don’t let cold weather slow you down; use our heated blankets to heat your engines. Explore Heated Blankets for Engines.
Don't let cold weather slow you down; start your engines by using our heated blankets to heat your engines.
