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Pilots do report longer flight time and more power gain but still there are FAQs.

Overview

To answer those FAQ, we need to start with knowing what flybar does and how it works. Flybar is the little seesaw perpendicular to the main blades, it has three missions:

1. Stablisation
2. Amplification of cyclic input
3. Compensation for pitch up

 

1. Stablisation

When a rotor head spins, the flybar and main blades form two planes. The centrifugal force makes the flybar plane parallel to the main blade plane. In a perfect "hands free" hovering, these two planes and the horizon are all parallel to each others and remain parallel. Under the external force from wind gust, the rotor plane tilts to an inclination, the gyroscopic force (angular momentum) of flybar spins the plane out of parallel of the rotor plane, the ball link then adjust the individual blade pitch to resist this intervention.

In most cases, the flybar plane itself also affected by wind, although not to the same extent the rotor blade plane, it depends on the mass of the flybar weights. Therefore, it only helps to minimise the inclination.

2. Amplification of cyclic input

Instead of swash plate directly pulling the main blades, the swash plate pulls the flybar cage. Paddles on the flybar utilise aerodynamic forces to change individual blade pitch to amplify the cyclic input. Thus load on the servos are only from the flybar, not the rotor blades; as such, less torque is required from the servo and less wear on servo gears.

3. Compensation for pitch up

In fast forward flight, the leading blade generates an extra uplifting force by impacting the upcoming air current; this causes heli keeps nose higher then commanded. In contrast, the flybar, again with the centrifugal force pulls the rotor plane down by adjusting the individual blade pitch.

 

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Flybarless with electronic device

Flybarless device, in short, is a combination of two head hold gyros along the two cyclic axis; both basically can work individually as the head hold tail gyro. With the ability of memorising the angle of intervened, the cyclic gyros are capable of commanding the cyclic servo to return the heli to the original position; thus providing more stable hover in strong wind.

In contrast to the traditional flybar system, flybarless does having lots of advantages over the traditional flybar system.

Mechanically, removing the flybar assembly simplifies the head structure allowing wider range of cyclic pitch without servo binding; plus cutting considerably amount of weight and slop. Head set up is so simple with as little as only two ball links, blade tracking is very easy.

Instead of commanding how far the servo horn moves, the cyclic input tells how fast the heli to roll or pitch. Reduction in air drag allows wider range of collective pitch without engine / motor bog, on the other hand, EP pilots can use lower power motor and battery pack with the same power output.

In more sophisticated design like the GyroBot, there are devices to help auto level the heli to a complete hands free hover.