As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING OUT .70 MACH 330 TAS FLIGHT EXPERIENCED UNCONTROLLED MOVEMENT SIMILAR TO ALTERNATELY PUSHING THE LEFT AND RIGHT RUDDER PEDALS GIVING THE FLIGHT A COMBINATION OF ROLL AND YAW. CUT POWER TO IDLE AND APPLIED 15 TO 20 DEGREES RIGHT AILERON AND THE AIRCRAFT STABILIZED. CONTINUED TO OMA. *S/D* REPLACED LOWER YAW DAMPER DUE TO FAILED BITE TEST. SYSTEM OPS CHECKS OK.