In aircraft design, Dutch roll results from relatively weaker positive directional stability as opposed to positive lateral stability. When an aircraft rolls around the longitudinal axis, a sideslip is introduced into the relative wind in the direction of the rolling motion. Strong lateral stability begins to restore the aircraft to level flight. At the same time, somewhat weaker directional stability attempts to correct the sideslip by aligning the aircraft with the perceived relative wind. Since directional stability is weaker than lateral stability for the particular aircraft, the restoring yaw motion lags significantly behind the restoring roll motion. As such, the aircraft passes through level flight as the yawing motion is continuing in the direction of the original roll. At that point, the sideslip is introduced in the opposite direction and the process is reversed.
ShanwickOceanic wrote:From the few comments I can actually read, it seems that this was the aircraft's first flight in 10 years, and shortly after takeoff they lost pitch and roll. They got it back down, using just rudder and throttle.
Balls of steel.
halls120 wrote:Any idea what would have caused them to lose pitch and roll control?
Zak wrote:This happened at Chkalovsky (don't ask me how to pronounce that) airfield, north-east of Moscow.
