In this study, we presented the design procedure of an optimal horn that achieves a certain requirement on the rudder pedal force with the minimum decrease in CHβ . The snaking behavior with this optimal horn is considerably enhanced.

Realizing the importance of CHβ in snaking behavior and the inability to increase it beyond a certain level (by decreasing the horn size), as it would increase the rudder pedal force, and realizing the availability of a Rudder-Assisted-System, we studied the effect of sideslip feedback into the rudder tab: δ_tab = −kβ. It is shown that there is an optimum value for the feedback gain k that completely suppresses snaking oscillations. It is also shown that this simple feedback controller is robust to delay and noise in β-measurements. The effect of other feedback (δ_tab = −kδ, δ_tab = −kδ˙) which are analogous to mechanical spring and damper for the rudder system is also studied. It is found that neither feedback (or their mechanical analogues) is capable of eradicating the snaking oscillations in comparison to the sideslip feedback. That is, no mechanical solution is likely to solve the snaking problem. Moreover, the same applies to a standard yaw-damper feedback (δ_tab = −kr); it does not suppress snaking oscillations. Note that, unlike regular Dutch roll oscillations, snaking is characterized by rudder oscillations (i.e., a free rudder). While a yaw damper can enhance Dutch roll oscillations, it cannot (alone) suppress the snaking behavior (in the presence of rudder oscillations).