A turboprop is a type of gas turbine engine that drives an aircraft propeller. It is a variant of a jet engine that has been optimized to drive a propeller. Turboprops are very efficient at lower flight speeds, burning less fuel per seat-mile and requiring significantly less runway for takeoff and landing than a turbojet or turbofan powered aircraft of the same size. They are perfect for safe, efficient regional travel.
A turboprop engine consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. The primary difference between a turboprop and a turbojet is that additional turbines, a power shaft, and a reduction gearbox have been incorporated into the design to drive the propeller. The propeller is coupled to the turbine through a reduction gear that converts the high RPM/low torque output to low RPM/high torque. There are two main types of turboprop engines: fixed-shaft and free-turbine.
Turboprops are generally used on small subsonic aircraft, but some larger military and civil aircraft have also been powered by turboprops. They are most efficient at speeds slower than 400 knots. While turboprops generally have lower service ceilings than turbofan or turbojet powered airplanes, they burn significantly less fuel per passenger. They are highly fuel-efficient with a much lower level of emissions than traditional jet engines, making them a part of the aviation industrys focus on sustainability.