A B737-300 in climb crew noted airframe vibration at FL310 cabin attendants noted severe vibration o...

Attributes
ACN	635712
Time
Date	200411
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl bound lower : 18000 msl bound upper : 31000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	635712
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other flight crewb other other : 3
Resolutory Action	flight crew : diverted to another airport
Consequence	other other
Supplementary
Problem Areas	Aircraft Environmental Factor Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

On climb from ZZZ through FL180, the captain and I noticed a loud hum. I called the flight attendants and they said they could hear the noise also and there was moderate vibration associated with it. The captain said there was a write-up previously dealing with aircraft vibration. The aircraft had an MEL 21-4 C1 dealing with that write-up. I then called maintenance control and told them about our problem. They looked up the aircraft history and told us about the MEL dealing with the pack turbo fan. The captain and I didn't feel that was the vibration we were hearing and feeling. The flight attendant then called us and said the vibration was bad overwing and that a couple of passenger had smelled burning rubber and that several passenger were getting extremely nervous and scared. I went to the cabin to check on the smell and vibration. I didn't notice any smell but the vibration was moderate overwing. At this point the captain decided to return to ZZZ. On descent into ZZZ, the vibration stopped as we came through FL180. No emergency was declared, the landing was overweight (117100 pounds), but everything else was normal. Callback conversation with reporter revealed the following information: the reporter said no information on the cause of the airframe vibration was been released.

Original NASA ASRS Text

Title: A B737-300 IN CLB CREW NOTED AIRFRAME VIBRATION AT FL310 CABIN ATTENDANTS NOTED SEVERE VIBRATION OVERWING AREA. FLT RETURNED TO DEP ARPT.

Narrative: ON CLB FROM ZZZ THROUGH FL180, THE CAPT AND I NOTICED A LOUD HUM. I CALLED THE FLT ATTENDANTS AND THEY SAID THEY COULD HEAR THE NOISE ALSO AND THERE WAS MODERATE VIBRATION ASSOCIATED WITH IT. THE CAPT SAID THERE WAS A WRITE-UP PREVIOUSLY DEALING WITH ACFT VIBRATION. THE ACFT HAD AN MEL 21-4 C1 DEALING WITH THAT WRITE-UP. I THEN CALLED MAINT CTL AND TOLD THEM ABOUT OUR PROB. THEY LOOKED UP THE ACFT HISTORY AND TOLD US ABOUT THE MEL DEALING WITH THE PACK TURBO FAN. THE CAPT AND I DIDN'T FEEL THAT WAS THE VIBRATION WE WERE HEARING AND FEELING. THE FLT ATTENDANT THEN CALLED US AND SAID THE VIBRATION WAS BAD OVERWING AND THAT A COUPLE OF PAX HAD SMELLED BURNING RUBBER AND THAT SEVERAL PAX WERE GETTING EXTREMELY NERVOUS AND SCARED. I WENT TO THE CABIN TO CHK ON THE SMELL AND VIBRATION. I DIDN'T NOTICE ANY SMELL BUT THE VIBRATION WAS MODERATE OVERWING. AT THIS POINT THE CAPT DECIDED TO RETURN TO ZZZ. ON DSCNT INTO ZZZ, THE VIBRATION STOPPED AS WE CAME THROUGH FL180. NO EMER WAS DECLARED, THE LNDG WAS OVERWT (117100 LBS), BUT EVERYTHING ELSE WAS NORMAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID NO INFO ON THE CAUSE OF THE AIRFRAME VIBRATION WAS BEEN RELEASED.

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.

A B737-300 in climb crew noted airframe vibration at FL310 cabin attendants noted severe vibration overwing area. Flight returned to departure airport.