RC helicopters require certain additions to their mechanics and technology to make them easier to fly. The flybar on an RC helicopter falls into this category of components. We will discuss the role the flybar plays in the control of your aircraft and how it helps control the helicopter.
The flybar on an RC helicopter is a rod or bar perpendicular to the helicopter’s main rotor. It is connected to the rotor head and moves with the swashplate. Weights or paddles on the ends of the flybar help to create stability for the rotor blades when the swashplate tilts the rotor disc.
The flybar on an RC helicopter is an important component in the steering and stability of the aircraft. Understanding how the flybar works will improve your knowledge of the helicopter’s mechanics and your flight control and troubleshooting skills.
What Is The Purpose Of A Flybar On RC Helicopters?
RC helicopters are one of the more complex RC aircraft to learn how to fly. A helicopter is not a very aerodynamic aircraft and requires the rotors to keep the aircraft aloft and stable in flight.
This characteristic of helicopters requires more mechanical components to keep the helicopter in the air and flying straight and true. The flybar is a feature that many RC helicopters have, which contributes to the control and stability of the aircraft.
Real-life helicopters do not have flybars; it is a feature unique to the RC helicopter. We will investigate this component’s role, location, and whether all RC helicopters have a flybar.
As part of our discussion, we will be using some terminology that may be unfamiliar to beginner RC helicopter operators. We will explain this terminology before continuing with understanding flybars.
|Helicopter Control Terminology|
|Angle of attack||The angle of the aerofoil leading edge of the main rotor blades or flybar paddles in relation to the airstream. The angle of attack affects the lift generated by the rotors.|
|Main rotors||The main rotors are the blades that spin on top of the helicopter, generating lift and providing control of the helicopter.|
|Rotor disc||The rotor disc is the imaginary disc drawn by the tips of the spinning main rotor. The rotor disc pitch is one component used to steer the helicopter.|
|Rotor head||The rotor head is the mechanism where the rotors are fixed to the shaft from the engine.|
|Swashplate||The swashplate is a mechanical part at the rotor head’s base that controls the rotor disc’s tilt or cyclic pitch for directional control. It also controls collective pitch for altitude adjustment.|
The flybar is an integral part of the steering mechanism of helicopters, which we cover in more detail in the article “How Do RC Helicopters Steer?”
Where Is The Flybar On An RC Helicopter?
The flybar is a rod with aerofoil paddles or weights at the end of it and is mounted on the helicopter rotor head in the same plane as the main rotors. Some flybars have a combination of weights and aerodynamic paddles at the end to increase the control and stability of the helicopter.
The flybar is connected via linkages to the swashplate, which controls the main rotors’ cyclic pitch and collective pitch.
As the swashplate moves to tilt the rotor disc, the flybar is tilted at the same time. The weights on the flybar balance the movement to make it smooth, and the aerodynamic shape of the paddles maintain the tilt angle accurately.
How Does The Flybar On RC Helicopters Work?
The flybar is connected to the swashplate by linkages that adjust the tilt of the flybar and the main rotors to steer the helicopter.
When the flybar is tilted, the angle of attack of the paddles at the ends of the flybar is changed, adjusting the lift generated by the paddles. The two ends of the flybar and the paddles work opposite each other.
When the paddle on one side is tilted down, the other side tilts up. When one paddle produces more lift, the other produces less.
When tilted, the additional forces provided by the flybar increase the main rotors’ stability when the rotor disc is tilted to steer the helicopter. The weighted ends of the flybar provide inertia and additional balance as the rotor disc is tilted and allows for smoother control of the rotor disc tilt.
The smoother control of the rotor disc tilt translates to a smoother response of the helicopter to the movement of the radio controls. The sensitivity of the radio controls can be adjusted to increase or decrease the amount of tilt in the flybar and rotor disc.
The ability to adjust the control sensitivity and the stability that the flybar offers to the rotor mechanism make the helicopter easier to fly and control. The flybar mechanism is particularly important for beginners who are new to flying RC helicopters.
The flybar affects how the steering works on an RC helicopter. Check out my article for more on how an RC helicopter steers
Do All RC Helicopters Have Flybars?
Due to the advancement in electronic components, RC helicopter manufacturers have begun replacing the flybar with electronic stabilization devices, which replace the function of the flybar.
These electronic components are similar to gyros and allow multi-axis main rotor stabilization electronically rather than with the additional physical flybar component. The flybar is replaced with a system of electronic gyros, sensors, and accelerometers that provide a smoother, more positive control of the tilt of the rotor disc.
The miniaturization of electronic components is the only reason this technology is now available for RC aircraft. Historically, the electronic components that were capable of performing these tasks were too large and heavy to place in a lightweight RC helicopter
The electronic stabilization simplifies the rotor head mechanism, making the setup of the helicopter rotor assembly easier. The electronic replacement for the flybar is sometimes referred to as a virtual flybar or electronic flybar since the electronics replace the function of this component.
Helicopters without flybars are often referred to as flybarless helicopters in the RC community. These helicopter designs are favored among experienced RC helicopter flyers because of the more true-to-life look of the flybarless helicopter.
Many miniature RC helicopters do not have the space capacity to install the electronics needed for flybarless operation, which is why flybar technology is still used in smaller model RC helicopters.
The flybar on an RC helicopter is intended to assist in tilting the rotor disc when steering the helicopter.
The weighted ends of the flybar help accentuate the rotors’ tilt, and the paddles on the flybar use increased or decreased lift to stabilize the movement and tilt of the main rotor assembly.
Electronics are taking over the role of the flybar in RC helicopters, and we may see these components disappearing from the hobby in several years.