Diversion to alternate mandated by an obvious trim problem. Flight crew suspected a fuel imbalance.

Attributes
ACN	317484
Time
Date	199510
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : takeoff ground : preflight ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : instrument pilot : commercial
Experience	flight time last 90 days : 100 flight time type : 3000
ASRS Report	317484
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe aircraft equipment problem : critical non adherence : far non adherence other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

An unscheduled landing in denver, co, of a B727 aircraft. This flight departed chicago the same day bound for slc. Takeoff was uneventful as was initial climb out and flap retraction. During climb out and after flap retraction and while the aircraft was accelerating to 250 KTS for climb out there was a need to increase rudder and/or aileron trim to keep the wings level due to an increase in the tendency of the aircraft to roll to the right. I put in about 3 units of rudder trim to cancel the roll. When rudder trim was taken out, the aircraft required 3 units of aileron trim to keep the wings level. This aircraft left chicago with an inoperative fuel gauge for the #1 fuel tank. The roll rate was suspected to come from an improper fuel balance from when the fuel was boarded. Although all the paperwork concerning fuel amount and boarding was properly executed and checked it was felt by the entire crew that a fuel imbalance might be the problem due to the fact that so much trim was needed to maintain wings level. With the #1 fuel gauge inoperative, it became suspect that a fuel problem might exist and for that reason after discussion with the rest of the crew, the captain elected to err on the side of safety and land the aircraft at a point in time that we knew was safe as far as fuel and all other considerations were concerned and that was denver, co. The landing was uneventful and the aircraft was removed from service pending resolution of the trim question.

Original NASA ASRS Text

Title: DIVERSION TO ALTERNATE MANDATED BY AN OBVIOUS TRIM PROB. FLC SUSPECTED A FUEL IMBALANCE.

Narrative: AN UNSCHEDULED LNDG IN DENVER, CO, OF A B727 ACFT. THIS FLT DEPARTED CHICAGO THE SAME DAY BOUND FOR SLC. TKOF WAS UNEVENTFUL AS WAS INITIAL CLBOUT AND FLAP RETRACTION. DURING CLBOUT AND AFTER FLAP RETRACTION AND WHILE THE ACFT WAS ACCELERATING TO 250 KTS FOR CLBOUT THERE WAS A NEED TO INCREASE RUDDER AND/OR AILERON TRIM TO KEEP THE WINGS LEVEL DUE TO AN INCREASE IN THE TENDENCY OF THE ACFT TO ROLL TO THE R. I PUT IN ABOUT 3 UNITS OF RUDDER TRIM TO CANCEL THE ROLL. WHEN RUDDER TRIM WAS TAKEN OUT, THE ACFT REQUIRED 3 UNITS OF AILERON TRIM TO KEEP THE WINGS LEVEL. THIS ACFT LEFT CHICAGO WITH AN INOP FUEL GAUGE FOR THE #1 FUEL TANK. THE ROLL RATE WAS SUSPECTED TO COME FROM AN IMPROPER FUEL BALANCE FROM WHEN THE FUEL WAS BOARDED. ALTHOUGH ALL THE PAPERWORK CONCERNING FUEL AMOUNT AND BOARDING WAS PROPERLY EXECUTED AND CHKED IT WAS FELT BY THE ENTIRE CREW THAT A FUEL IMBALANCE MIGHT BE THE PROB DUE TO THE FACT THAT SO MUCH TRIM WAS NEEDED TO MAINTAIN WINGS LEVEL. WITH THE #1 FUEL GAUGE INOP, IT BECAME SUSPECT THAT A FUEL PROB MIGHT EXIST AND FOR THAT REASON AFTER DISCUSSION WITH THE REST OF THE CREW, THE CAPT ELECTED TO ERR ON THE SIDE OF SAFETY AND LAND THE ACFT AT A POINT IN TIME THAT WE KNEW WAS SAFE AS FAR AS FUEL AND ALL OTHER CONSIDERATIONS WERE CONCERNED AND THAT WAS DENVER, CO. THE LNDG WAS UNEVENTFUL AND THE ACFT WAS REMOVED FROM SVC PENDING RESOLUTION OF THE TRIM QUESTION.

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.