Understanding your aircraft’s power-source is incredibly important. From Pistons to Turbo-Jets, there is a broad spectrum of engines used for diverse flying. With specific training for different equipment, a brief overview of three common engines could help you choose a path in aviation.
Piston engines are the type most commonly found on primary training aircraft, both for fixed wing airplanes and helicopters. Piston engines are internal combustion engines and operate on the exact same principal as most automobile engines. However, the majority of piston engines designed for aircraft are different than your car engine in several ways: they are air/oil cooled, they mostly use magnetos for an ignition source (just like your lawnmower!), and they are designed to operate at very high power settings over the life of the engine. If you’re learning to fly, chances are your flying behind a piston engine.
The Turbo-Jet created in World War 2 fighters lead to the the safer and more reliable Turbo-Fan commonly used in commercial flight. Turbo-Fans are most efficient at 500-550 knots and have both low and high bypass systems. Low Bypass systems are commonly used in military aircraft because of increased power to weight ratio, while High Bypass engines are used in commercial aviation due to great fuel efficiency and low noise. Turbo-Fans were also the first engines to use multiple spools which allows the engine to react more quickly to changing power requirements.
The Turbo-Prop stems from a combination of military technology and civilian needs. Gas turbines require low maintenance and offer high power. Engine manufacturers mounted a propeller on a gas turbine, and an efficient and incredibly low maintenance engine was born. Turbo-Props are currently used for both private and regional commercial flights.
While you may think helicopter engines are vastly different than fixed wing aircraft engines, they’re actually incredibly similar! However, there is one main difference: while the Turbo-Prop propeller is supported by the engine, a Turbo-Shaft does not provide any physical support to the helicopter’s rotors. Most Turbo-Shaft engines are used for helicopters and are often times produced by Turbo-Prop manufacturers because both engines are based on similar designs.
As we all know, understanding your equipment is of the utmost importance in aviation. While these are only short summaries of three primary engine types, there are aircraft engine resources that offer a vast amount of information on a broad spectrum of engine design.