A300 ACFT HAS HEAVY VIBRATION DURING CLB OUT AND FLT CREW ELECTS TO RETURN TO DEP ARPT.

Narrative

UPON CLB OUT THE FLOOR BELOW MY SEAT AT 2R WAS VIBRATING WHICH I NOTICE. AT THE END OF STERILE COCKPIT; 10000 FT; I GOT UP AND STARTED BACK TO THE TAIL OF THE ACFT. #3 TOLD ME HER FLOOR AND DOOR WAS ALSO VIBRATING; #2 SAID HE HAD HEAVY VIBRATION AT HIS DOOR 4L. WE CALL THE COCKPIT; INFORMED THE CAPT OF OUR FINDINGS. HE SAID HE HAD VIBRATION ON THE STICK TOO; SO WE WOULD GO BACK TO ZZZ. WE LANDED WITHOUT INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HER POSITION WAS AT DOOR 2R AND THE VIBRATION WAS EQUATED AS 4 OR 5 ON A TEN POINT SCALE. AS SHE PROCEEDED TOWARD THE REAR OF THE ACFT THE VIBRATION INCREASED TO A LEVEL OF 8 OR 9 ON A TEN POINT SCALE. THE WINDOW SHADES AND FLOOR WERE SHAKING AND EVERY CABIN CREW MEMBER BECAME VERY CONCERNED AS THE VIBRATION INCREASED. THE RPTR INDICATED THAT THE MOST SEVERE VIBRATION APPEARED TO BE NEAR THE RIGHT REAR TAIL SECTION. THE CABIN CREW WAS VERY SENIOR; WITH AN AVERAGE OF 30 YRS OF SVC. ADDITIONALLY; WHEN THE FLT CREW WAS NOTIFIED OF THE VIBRATION THE CAPT STATED THAT HE FELT THE VIBRATION IN THE CONTROL STICK. THE RPTR INDICATED THE ACFT WAS TAKEN OUT OF SVC AFTER RETURNING TO THE DEP ARPT. SUPPLEMENTAL INFO FROM ACN 572645: WE WERE DE-ICED ON THE GND. UPON TKOF THERE WAS SEVERE VIBRATION AT MY DOOR (3L). AS SOON AS IT WAS SAFE; I WENT TO THE REAR OF THE ACFT WHERE THE VIBRATION CONTINUED. AFTER TALKING TO THE OTHER FLT ATTENDANTS WE WALKED THROUGH M/C TO DETERMINE WHERE THE VIBRATION BEGAN AND ENDED. THE FLOOR WAS VIBRATING HEAVILY UP TO ABOUT ROW 17. I RETURNED TO THE BACK OF THE ACFT CALLED THE CAPT AND HE DECIDED TO RETURN TO ZZZ. I BELIEVE HE DECLARED AN EMER LNDG AS NO FUEL WAS DUMPED AND WE WERE MET BY EMER VEHICLES. IN ABOUT 20 MIN WE LANDED SAFELY; CHANGED ACFT AND CONTINUED ON. THERE WAS NO EVACUATION AND NO INJURIES.