There are many different types of aircraft heating systems that are available depending on the type of aircraft. Regardless of which type or the safety features that accompany them, it is always important to reference the specific aircraft operator’s manual and become knowledgeable about the heating system. Each has different repair and inspection criteria that should be precisely followed.

Fuel Fired Heaters

A fuel fired heater is a small mounted or portable spaceheating device. The fuel is brought to the heater by using piping from a fuel tank, or taps into the aircraft’s fuel system. A fan blows air into a combustion chamber, and a spark plug or ignition device lights the fuel-air mixture. A built-in safety switch prevents fuel from flowing unless the fan is working. Outside the combustion chamber, a second, larger diameter tube conducts air around the combustion tube’s outer surface, and a second fan blows the warmed air into tubing to direct it towards the interior of the aircraft. Most gasoline heaters can produce between 5,000 and 50,000 British Thermal Units (BTU) per hour. 

Fuel fired heaters require electricity to operate and are compatible with a 12-volt and 24-volt aircraft electrical system. The heater requires routine maintenance, such as regular inspection of the combustion tube and replacement of the igniter at periodic intervals. Because gasoline heaters are required to be vented, special care must be made to ensure the vents do not leak into the interior of the aircraft. Combustion byproducts include soot, sulfur dioxide, carbon dioxide, and some carbon monoxide. An improperly adjusted, fueled, or poorly maintained fuel heater can be dangerous. 

Exhaust Heating Systems 

Exhaust heating systems are the simplest type of aircraft heating system and are used on most light aircraft. Exhaust heating systems are used to route exhaust gases away from the engine and fuselage while reducing engine noise. The exhaust systems also serve as a heat source for the cabin and carburetor.  

The risks of operating an aircraft with a defective exhaust heating system include carbon monoxide poisoning, a decrease in engine performance, and an increased potential for fire. Because of these risks, technicians should be aware of the rate of exhaust heating system deterioration and should thoroughly inspect all areas of the exhaust heating system to look for deficiencies inside and out.

Combustion Heater Systems 

Combustion heaters or surface combustion heaters are often used to heat the cabin of larger, more expensive aircraft. This type of heater burns the aircraft’s fuel in a combustion chamber or tube to develop required heat, and the air flowing around the tube is heated and ducted to the cabin. A combustion heater is an airtight burner chamber with a stainless-steel jacket. Fuel from the aircraft fuel system is ignited and burns to provide heat. Ventilation air is forced over the airtight burn chamber picking up heat, which is then dispersed into the cabin area.