Specifications

Chapter 29. Helicopter Myths
29.1. Expo is bad because it slows cyclic response
This is incorrect, because expo does not slow down the cyclic response. It only decrease the
amount of cyclic response near center stick while retaining full control throw at the stick ex-
tremes.
Regardless of how much expo you use, the heli will flip or roll at the same rate with full cyclic.
29.2. Heading hold gyros are bad
Some people say "heading hold gyros are like cheating" but this is usually the result of mach-
ismo and lack of understanding. A heading hold gyro not only make hovering easier, it will
teach you to use the rudder deliberately to change the orientation of the helicopter.
With a yaw rate gyro, the tail will naturally swing behind the helicopter in the direction of mo-
tion. This will develop sloppy rudder technique which is difficult to correct later. Note that the
top pilots in the world, such as Curtis Youngblood, Alan Szabo, etc all use heading hold gyros,
not yaw rate gyros.
29.3. Shorter flybar increases cyclic response
Imagine a flybar so short the paddles touch the head. With this length flybar, the paddles will
be traveling in a small circle and have very little airspeed, so they will not exert much force to
change the main rotor blade pitch.
Also, since the flybar is so short, the paddles will also have less leverage against the main ro-
tor blades and will exert even less force to change the main rotor blade pitch.
Therefore, a longer flybar increases the cyclic response, not a shorter flybar.
29.4. Rate gyros do not need revo mixing
If you mechanically trim the tail pitch so the hovering thrust naturally corresponds to the rudder
neutral position, then you may believe you don't need revo mix. However, as soon as you
throttle up or down, the tail will swing around because the tail rotor thrust will not increase nor
decrease due to the lack of revo mixing.
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