Types of Helicopter Engines

Types of Helicopter Engines

Helicopters have long been a vital part of the aviation industry, providing versatile and agile capabilities for various applications such as search and rescue, medical transport, military operations, and more. At the heart of these machines lies the powerplant – the helicopter engine.

Understanding the types of helicopter engines available, their advantages, and the applications they are best suited for is essential for anyone interested in the world of rotary-wing aircraft.

This article explores the four main types of helicopter engines: piston engines, turboshaft engines, electric engines, and hybrid engines. We will discuss their unique advantages and examine how each type is utilized in the industry.

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Piston Engines: The Classic Choice

Piston engines, also known as reciprocating engines, have been used in helicopters since the early days of aviation. These engines use a series of pistons to convert linear motion into rotational motion, which then drives the helicopter’s rotor system.

Piston engines are commonly found in smaller helicopters and training aircraft, as they are generally more affordable and easier to maintain than other engine types.

Advantages of Helicopter Piston Engines:

  • Lower initial cost: Piston engines are often less expensive to purchase and install compared to other types of helicopter engines.
  • Simplicity: The design of piston engines is relatively simple, making them easier to understand, maintain, and repair.
  • Proven technology: Piston engines have been used for many years, providing a reliable and well-understood option for helicopter operators.

Turboshaft Engines: Power and Efficiency

Turboshaft engines are the most widely used in modern helicopters, particularly in medium to large-sized aircraft. These engines use a gas turbine to drive a shaft, which in turn powers the helicopter’s rotor system.

Turboshaft engines offer significant advantages in terms of power and efficiency, making them the go-to choice for many helicopter applications.

Advantages of Helicopter Turboshaft Engines:

  • High power-to-weight ratio: Turboshaft engines provide a significant amount of power for their size, making them well-suited for helicopters that require high levels of performance.
  • Reliability: Turboshaft engines are known for their reliability and low maintenance requirements, which can result in reduced downtime and increased operational availability.

Electric Engines: The Future of Sustainable Aviation

As the aviation industry continues to prioritize sustainability and environmental responsibility, helicopter electric engines have emerged as a promising solution for helicopter propulsion.

These engines use electric motors to drive the rotor system, drawing power from onboard batteries or fuel cells. While electric helicopters are still in the early stages of development, they hold significant potential for reducing the environmental impact of aviation.

Advantages of Helicopter Electric Engines:

  • Zero emissions: Electric engines produce no harmful emissions during operation, making them an environmentally friendly option for helicopter propulsion.
  • Reduced noise pollution: Electric engines are significantly quieter than their piston or turboshaft counterparts, resulting in less noise pollution for communities near flight paths.
  • Lower operating costs: Electric engines have fewer moving parts and require less maintenance, which can lead to lower operating costs over time.

Hybrid Engines: Combining the Best of Both Worlds

Hybrid helicopter engines combine elements of both conventional and electric propulsion systems, providing a balance between performance and sustainability. These engines typically utilize a small gas turbine or piston engine to generate electricity, which is then used to power electric motors that drive the rotor system.

Hybrid engines offer a compromise between the high power output of turboshaft engines and the environmental benefits of electric engines, making them an attractive option for future helicopter development.

Advantages of Hybrid Engines:

  • Improved fuel efficiency: Hybrid engines can achieve better fuel efficiency than conventional engines, reducing operating costs and environmental impact.
  • Reduced emissions: By combining electric and conventional propulsion, hybrid engines produce fewer emissions than their non-hybrid counterparts.
  • Flexible power management: Hybrid systems can switch between electric and conventional power sources, allowing for improved performance and range capabilities.

Applications of Different Helicopter Engines

Now that we’ve discussed the four main types of helicopter engines, let’s take a closer look at the applications each type is best suited for:

Piston Engines: Ideal for training and light utility roles, piston engines are commonly used in small helicopters such as the Robinson R22 and Schweizer 300. These aircraft are often used for flight training, aerial photography, and other light-duty tasks.

Turboshaft Engines: Widely used in medium to large-sized helicopters, turboshaft engines are the go-to choice for many commercial, military, and emergency services applications. Examples of turboshaft-powered helicopters include the Sikorsky UH-60 Black Hawk, Airbus H225, and Bell 412.

Electric Engines: While still in the early stages of development, electric helicopters hold promise for urban air mobility and other applications where low noise and emissions are crucial. The Volocopter VoloCity and EHang 216 are examples of electric helicopters currently under development.

Hybrid Engines: As hybrid helicopter technology continues to mature, we can expect to see increased adoption in a range of applications, from military and commercial transport to search and rescue missions. The Bell Nexus and Airbus RACER are examples of hybrid helicopters currently in development.


Helicopter engines play a critical role in determining the performance, efficiency, and sustainability of rotary-wing aircraft. By understanding the advantages and applications of each engine type, operators and enthusiasts alike can make informed decisions when selecting the right helicopter for their needs.

As the aviation industry continues to evolve, we can expect to see further advancements in engine technology, leading to more efficient and environmentally friendly helicopters in the years to come.