Narrative:

After takeoff from ZZZ on climb out, a definite vibration was felt in business class and first class. There was noise and the cabin temperature was warm. The captain was notified. The vibrations had worsened. The captain asked us our opinion but did not leave cockpit. We circled approximately 1 hour and went back to ZZZ (no fuel dumped). We arrived in ZZZ, mechanics said cargo door was not sealed tight. We landed heavy. The mechanics fixed problem and signed off. We took off again and exactly the same problem occurred, only worse. We circled again approximately 1 hour and landed heavy back in ZZZ. We changed aircraft and flew to jfk departing at XA55 (approximately). This item had been written up in the logbook before we even took off the first time but signed off. Supplemental information from acn 520796: flight attendants reported vibration at mid cabin. Could also detect the vibration on the flight deck. Additionally we were unable to maintain the proper temperature in the aircraft. Aircraft had cdl removing ram air door off the left pack. Did not declare an emergency with ATC. After landing maintenance determined that the left pack exhaust door had not been properly locked open as per the cdl. Exhaust door was locked open and overweight inspection accomplished. After second departure, same vibration problem. Returned to ZZZ and did second overweight landing. Did not declare an emergency with ATC. Upon review of flight manual determined policy is overweight lndgs are an emergency and I should have declared an emergency with ATC to comply with manual, even though I did not require any special handling. Dispatch informed ATC of overweight status on first landing and emergency equipment was sent out. On second landing no equipment was requested. Performance limits of aircraft were not a factor due to weight and runway length.

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Original NASA ASRS Text

Title: A B767-300 RETURNED TO THE DEP STATION TWICE WITH AIRFRAME VIBRATION. ACFT HAD PREVIOUS VIBRATION RPTS NOT CORRECTED.

Narrative: AFTER TKOF FROM ZZZ ON CLBOUT, A DEFINITE VIBRATION WAS FELT IN BUSINESS CLASS AND FIRST CLASS. THERE WAS NOISE AND THE CABIN TEMP WAS WARM. THE CAPT WAS NOTIFIED. THE VIBRATIONS HAD WORSENED. THE CAPT ASKED US OUR OPINION BUT DID NOT LEAVE COCKPIT. WE CIRCLED APPROX 1 HR AND WENT BACK TO ZZZ (NO FUEL DUMPED). WE ARRIVED IN ZZZ, MECHS SAID CARGO DOOR WAS NOT SEALED TIGHT. WE LANDED HVY. THE MECHS FIXED PROB AND SIGNED OFF. WE TOOK OFF AGAIN AND EXACTLY THE SAME PROB OCCURRED, ONLY WORSE. WE CIRCLED AGAIN APPROX 1 HR AND LANDED HVY BACK IN ZZZ. WE CHANGED ACFT AND FLEW TO JFK DEPARTING AT XA55 (APPROX). THIS ITEM HAD BEEN WRITTEN UP IN THE LOGBOOK BEFORE WE EVEN TOOK OFF THE FIRST TIME BUT SIGNED OFF. SUPPLEMENTAL INFO FROM ACN 520796: FLT ATTENDANTS RPTED VIBRATION AT MID CABIN. COULD ALSO DETECT THE VIBRATION ON THE FLT DECK. ADDITIONALLY WE WERE UNABLE TO MAINTAIN THE PROPER TEMP IN THE ACFT. ACFT HAD CDL REMOVING RAM AIR DOOR OFF THE L PACK. DID NOT DECLARE AN EMER WITH ATC. AFTER LNDG MAINT DETERMINED THAT THE L PACK EXHAUST DOOR HAD NOT BEEN PROPERLY LOCKED OPEN AS PER THE CDL. EXHAUST DOOR WAS LOCKED OPEN AND OVERWT INSPECTION ACCOMPLISHED. AFTER SECOND DEP, SAME VIBRATION PROB. RETURNED TO ZZZ AND DID SECOND OVERWT LNDG. DID NOT DECLARE AN EMER WITH ATC. UPON REVIEW OF FLT MANUAL DETERMINED POLICY IS OVERWT LNDGS ARE AN EMER AND I SHOULD HAVE DECLARED AN EMER WITH ATC TO COMPLY WITH MANUAL, EVEN THOUGH I DID NOT REQUIRE ANY SPECIAL HANDLING. DISPATCH INFORMED ATC OF OVERWT STATUS ON FIRST LNDG AND EMER EQUIP WAS SENT OUT. ON SECOND LNDG NO EQUIP WAS REQUESTED. PERFORMANCE LIMITS OF ACFT WERE NOT A FACTOR DUE TO WT AND RWY LENGTH.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.