As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 3355 - DIV - DIVERTED TO NRT DUE TO REGULAR AND RHYTHMIC VIBRATION NOTED. LEFT OUTBOARD AILERON FLUTTER SHOWS CONSTANT MOVEMENT, MOST EVIDENT ABOVE 250 KIAS. CORRECTIVE ACTION: MAINTENANCE REPLACED BOTH OUTBOARD AILERON SERVOS AND THE #1 FLIGHT CONTROL SECONDARY COMPUTER. LP 5063352