Dutch roll is a coupled lateral-directional oscillation in swept-wing aircraft. Which action best helps prevent or correct it?

Dutch roll is a coupled lateral-directional oscillation in swept-wing aircraft. Which action best helps prevent or correct it?

• A. Engage the yaw damper
• B. Increase rudder input during turns
• C. Lower the tailplane incidence
• D. Reduce airspeed to stall speed

Answer: (A)

Dutch roll is a coupled lateral-directional oscillation that can arise in swept-wing aircraft due to the interaction between yaw and roll. The best way to prevent or correct it is to use the yaw damper, which automatically provides damping on the yaw axis. By sensing yaw rate (and sometimes sideslip) and applying small, timely rudder corrections, the damper counters the oscillation, reducing its amplitude and preventing growth. This directly addresses the dynamic coupling that causes Dutch roll and stabilizes the aircraft. Other options don’t address the damping of the yaw motion. Increasing rudder input during turns can feed energy into the oscillation and potentially make it worse. Lowering tailplane incidence changes static stability but doesn’t provide the necessary dynamic damping. Reducing airspeed to stall speed degrades handling and does not fix the underlying damping issue.

Dutch roll is a coupled lateral-directional oscillation that can arise in swept-wing aircraft due to the interaction between yaw and roll. The best way to prevent or correct it is to use the yaw damper, which automatically provides damping on the yaw axis. By sensing yaw rate (and sometimes sideslip) and applying small, timely rudder corrections, the damper counters the oscillation, reducing its amplitude and preventing growth. This directly addresses the dynamic coupling that causes Dutch roll and stabilizes the aircraft.

Other options don’t address the damping of the yaw motion. Increasing rudder input during turns can feed energy into the oscillation and potentially make it worse. Lowering tailplane incidence changes static stability but doesn’t provide the necessary dynamic damping. Reducing airspeed to stall speed degrades handling and does not fix the underlying damping issue.