As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT, A STRONG (FWD-AFT) VIBRATION WAS FELT ON THE CAPTAIN YOKE. CREW LEVELED OFF AT 2000 FT, VIBRATION CONTINUED FROM 150-200 KTS. CREW REDUCED SPEED TO 180 KTS, RETURNED TO FIELD WITH VIBRATION CONTINUING UNTIL FLAPS RETRACTED.