AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

What Are the Different Parts of a Rotorcraft?

Out of the various heavier-than-air classes of aircraft, rotorcrafts have long stood out as versatile machines and an example of advanced aviation engineering. Whether they are being used for medical evacuation, military operation, or sightseeing tours, rotorcraft have proven to be an invaluable asset in modern society. In this blog, we will discuss the many parts that make up a rotorcraft and how they work together to get these peculiar aircraft off the ground.


The fuselage is the most external portion of the airframe. Depending on the application, the fuselage may vary greatly in size from a personal 2-seater helicopter to a cargo aircraft capable of holding 10,000lbs and over ten passengers. In addition to the storage and seating area, the fuselage also houses the engine, transmission, flight controls, and other crucial components.

Main Rotor System

The main rotor system is made of several components which work together to produce lift. In the center is a large vertical cylinder called the mast, which acts as the attachment point for the hub and blades. The hub is the connection point between the blades and the mast. This too varies in size depending on the number and size of attached blades.

The most common configuration for blade attachment is the semirigid rotor system, which uses two blades directly mounted to the hub. Another setup is the rigid rotor system, which consists of two or more blades that sit lower than the hub and are connected by an articulated blade piece. Finally, the complex fully articulated rotor system allows each blade to move independently among three axes. While this configuration provides the pilot with better control, it is more expensive and mechanically complicated than the others.

Swashplate Assembly

The swashplate controls the movement of the rotor through the pilot's flight controls. It accomplishes this through two assemblies, one of which is stationary and connects directly to the pilot cyclic and collective controls, while the other is connected to the main rotor mast.

Freewheeling Unit

In the case of engine failure, the blades must continue to rotate freely in order to maintain lift for a short amount of time. The freewheeling unit ensures this by disengaging the main rotor from the engine's control when it senses a sudden loss in RPM.

Antitorque System

Some helicopters require an antitorque system to prevent the aircraft from rotating around its own axis. In most cases, this is accomplished by the tail rotor system, which provides force in the opposite direction of that created by the main rotor.


Like every heavier-than-air aircraft, rotorcraft use engines to help generate lift. In small or training helicopters, reciprocating engines are commonly used since they are inexpensive and easy to maintain. However, the more powerful turbine engines are preferred in nearly every other application.

Transmission System

Much like an automobile, the transmission system uses the power created by the engine to drive the various rotors. Since these systems are crucial at all times of flight, they are typically lubricated and cooled by an independent oil supply.

Dual Tachometers

The dual-needle tachometer is an instrument that simultaneously displays engine and rotor RPM on the same display. In normal operating conditions, the needles are generally coupled and move linearly. However, if engine failure were to occur, the engine needle would have a sudden drop in RPM, while the rotor side would remain stable for a short amount of time.

Fuel Systems

Rotorcraft either use gravity or pump-feed systems to deliver fuel into the engine's combustion chamber.

Electrical Systems

Most helicopters use a 14 or 28 volt DC power system to supply electricity to the avionic and onboard entertainment systems. They also use a battery for the engine start sequence, which can provide power to other vital equipment for a limited amount of time. Even with the sophisticated avionics systems on modern helicopters, most can continue to fly fine without electrical power in the case of an emergency.


As aircraft have continued to increase in size over time, so has the demand for flight control systems. In order to help the aircraft overcome the excessive workload presented by the increased loads, modern helicopters make use of complex hydraulic systems.

Environmental Systems

Adequate cabin temperature control is important for both occupant comfort and safety. While in flight, the pilot may open the several air ducts positioned on the front or sides of the helicopter to let ram air into the cabin. Compressed-air HVAC systems may also be implemented, but this equipment requires continuous electrical power during operation.

When you are in need of high quality rotorcraft components to support your operational requirements, choose Fasteners 360 as your one-stop-shop. As an AS9120B, ISO 9001:2015, and FAA AC 00-56B accredited distributor, we regularly subject our inventory to rigorous testing to screen for any potential problems before shipping. We are also the only independent distributor to maintain a strict NO CHINA Sourcing pledge, meaning that every order is fully traceable or comes directly from one of the leading manufacturers we work with. Submit an RFQ form or contact our team today to begin the purchasing process and experience the evolution of parts procurement.


Recent Twitter Posts

Semiconductor's Certifications and Memberships
The only independent
distributor with a
  • All orders are fulfilled in the USA.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.
fallen heroes fund logo

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website ( and help in their valiant effort”.

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote

We use cookies to ensure that we give you the amazing experience on our website. If you continue to use this site we will assume that you are happy with it.