What is a Turboprop Engine?

For an aircraft to achieve and sustain flight as we are familiar with today, they require some method of producing propulsion and thrust. For aircraft that need high amounts of combustion and force to drive their systems, gas turbine engines prove to be the most widely used types. With the turboprop engine in particular, the combustion of fuel-and-air mixtures is harnessed to drive propellers, unlike other gas turbine types. From business jets to military attack aircraft, turboprop engines prove very popular for a variety of aerospace applications. To best understand their usefulness for certain aircraft, it can be very beneficial to first be aware of their design and functionality.

While a turboprop engine may vary slightly in its design across different aircraft, most contain similar parts that enable standard operation during flight. Across most engines, turboprops will feature aircraft parts such as an intake, reduction gearbox, compressor, combustor, turbine, and propelling nozzle. During a typical flight, air is drawn into the engine through the intake, and the compressor then increases the pressure of the air to an optimal point for combustion due to altitude. Within the combustor, fuel is mixed together with the compressed air before being ignited, resulting in rapidly expanding, hot exhaust gases. As the exhaust gases expand and push further through the turboprop engine, its force drives turbine blades and reduction gearing. While the energy harnessed by the turbine is used to drive the compressor, the reduction gearing transmits its power to the propeller for propulsion. Once gases have been spent and lose their energy, they are expelled from the system at atmospheric pressure as the cycle of intake, combustion, and expulsion continues.

As compared to other popular engine types, the turboprop engine features various benefits that can make it advantageous for specific applications and needs. As compared to piston-powered propeller aircraft, the turboprop ensures constant speed, full feathering, and the ability to reverse the propeller. Additionally, turboprop engines are highly reliable and can achieve a shorter takeoff through their greater power-to-weight ratios. Despite this, turboprops will have more required maintenance, spend more fuel for flight, and come with a higher initial cost as compared to piston engines.

With their method of operation and capabilities, the turboprop engine is most efficient while traveling at speeds below 450 mph (725 km/h). This is due to the fact that the velocity of the propeller and exhaust is lower as compared to other turbine engines such as the turbofan. As a result, turboprops are incapable of using expelled gases to provide more thrust, as all energy is used to drive the turbine and propellers. Regardless, turboprop engines can provide a high advantage to airliners and similar aircraft in terms of fuel efficiency, as many modern turboprop airliners are capable of traveling at similar speeds to smaller regional jet airliners while burning one-third less fuel per passenger. As such, the choice between engine types will often depend on the intended use of the aircraft. Generally, the main reasons that operators choose turboprop engines is due to their lightweight construction, mechanical reliability, simplicity of operation, high power-to-weight ratios, and minimum vibrations faced during flight.

With a well maintained turboprop engine, conducting flights for business, defense, or transportation can be done with ease. When you are in need of engine components and aircraft parts that you can steadily rely on, ASAP NSN Distribution is your sourcing solution with over 2 billion new, used, and obsolete items. As a premier online distributor of aircraft parts, we can help you secure top quality compressors, propellers, and other items from leading global manufacturers. Get started on the purchasing process today with a competitive quote when you submit an Instant RFQ form through our website.