No noise or air pollution. Electric motors are silent and there are no emissions such as smoke or any other harmful gases, which is the bane of gasoline-powered engines, especially the 2-stroke ones. Hence there are fewer restrictions and fewer chances of complaints in case of flying electric planes.

Simple construction. Electric motors also have fewer parts as compared to a gasoline engine, which could consist of pistons, cranks, valves, carburetors, etc. This makes the electric motor much more reliable than a gasoline one. The brush less electric motor hardly requires any maintenance at all in its entire life, whereas a gasoline engine will require valve settings after a set time of flying, and will also need continuous lubrication during it's flight. This oil is mixed along with the fuel and hence the engine tends to 'smoke' during flight and this method also produces a thin film of oil due to the un-burnt oil. Gasoline engines also require a sturdy cradle and frame since there is a lot of vibration during running as compared to an electric motor, which hardly has any vibrations.

Simple to use. There are no settings to be done to an electric motor but the gasoline engine has to be set for optimum 'rpm' via a setting screw in it's carburetor. This makes it difficult for 'new pilots' to adjust the rpm to get the optimum power out of the engine.

Good value for current. If you compare the efficiency of a brush less electric motor to a gasoline engine, the former is far more efficient. The electric motor is almost twice as efficient as a gasoline-powered engine. Electric motors are also easily geared for use with bigger sized propellers whereas gasoline powered engines might need a complex clutch system to get it to do the same job. Different climatic changes such as heat, cold or humidity do not have any effect on the electric motor but the settings in the gasoline engine might have to be changed as per the climatic conditions.

Flexibility in charging. Whereas an electric motor can be re-charged in a number of ways such as from the home, car, etc, a gasoline engine requires the perfect combination of the correct fuel and the correct percentage of oil mixed in it. Otherwise the engine could seize during flight. It is due to these factors that electric motors are now being used in model airplanes, helicopters, cars, boats, etc.

So, due to its efficient and silent design, ease of maintenance and running, electric motors are preferable modes of powering up your model airplane and the reasons mentioned above should convince you to design and build a model airplane with an electric heart and soul.