Jet engines create enormous thrust to power aircraft through the air. An electric motor begins the rotation of a large multi-bladed fan on a center shaft at the front of the engine to draw in air. Then a combination of the air, fuel and a spark create combustion that forces heated gas through a turbine at high velocity to rotate it and begin creating jet propulsion.
The most commonly used jet engine in today's airliners is the turbofan type. An electric motor initiates the rotation of a multi-bladed fan in the front of the engine. As the rotation increases, the fan begins to suck air in. The air is then compressed and sent into a combustion chamber where fuel is sprayed into it and the mixture is ignited by a spark. This creates a high-pressured flaming gas that rushes through a turbine, also consisting of multiple blades, and causes it to rotate at a high speed. The spinning turbine keeps the fan rotating and the compressor operating so the entire combustion cycle is repeated. The heated gas from the turbine is forced out of the rear of the engine through an exhaust duct, or nozzle, to increase the velocity of the gas and create enough thrust to propel the aircraft through the air. Other types of jet engines include turboprops, turboshafts and ramjets. Although they differ slightly in operation, the overall concept is the same; air is drawn in, mixed with fuel, ignited and expelled from the rear of the engine to create thrust.