B737-200 crew had an airframe vibration that seemed to be associated with an engine.

Attributes
ACN	602795
Time
Date	200312
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ztl.artcc
State Reference	GA
Altitude	msl bound lower : 10000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 210 flight time total : 7900 flight time type : 850
ASRS Report	602795
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other other : 3
Resolutory Action	controller : issued new clearance flight crew : landed as precaution flight crew : diverted to another airport
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

During initial climb and cruise flight, aft flight attendant told pilots that there was a pronounced vibration that could be felt and heard from back half of aircraft. Vibration could also be noticed in cockpit. After troubleshooting it was determined that vibration was less prominent when thrust was reduced, but reestablished when thrust increased. With concurrence from dispatcher, flight crew diverted to atlanta and made a precautionary landing short of scheduled destination. Vibration persisted for remainder of flight. Aircraft arrived in atlanta without incident, logbook entry was made, and aircraft was turned over to company maintenance personnel upon arrival.

Original NASA ASRS Text

Title: B737-200 CREW HAD AN AIRFRAME VIBRATION THAT SEEMED TO BE ASSOCIATED WITH AN ENG.

Narrative: DURING INITIAL CLB AND CRUISE FLT, AFT FLT ATTENDANT TOLD PLTS THAT THERE WAS A PRONOUNCED VIBRATION THAT COULD BE FELT AND HEARD FROM BACK HALF OF ACFT. VIBRATION COULD ALSO BE NOTICED IN COCKPIT. AFTER TROUBLESHOOTING IT WAS DETERMINED THAT VIBRATION WAS LESS PROMINENT WHEN THRUST WAS REDUCED, BUT REESTABLISHED WHEN THRUST INCREASED. WITH CONCURRENCE FROM DISPATCHER, FLT CREW DIVERTED TO ATLANTA AND MADE A PRECAUTIONARY LNDG SHORT OF SCHEDULED DEST. VIBRATION PERSISTED FOR REMAINDER OF FLT. ACFT ARRIVED IN ATLANTA WITHOUT INCIDENT, LOGBOOK ENTRY WAS MADE, AND ACFT WAS TURNED OVER TO COMPANY MAINT PERSONNEL UPON ARR.

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.