As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VIBRATION SHUDDER OCCURS AT HIGH SPEED ABOVE 230 KNOTS, FEELS LIKE LOW FREQUENCY SHAKE LIKE BUFFETING. REMOVED AND REPLACED FLIGHT CONTROL COMPUTER IAW SAAB AMM 34-22-05. OPERATIONAL CHECK GOOD, PERFORMED FUNCTIONAL CHECK FLIGHT WITH NO DEFECTS. AIRCRAFT RETURNED TO SERVICE.