Air carrier heavy had stabilizer trim problem during climb. Flight crew was unable to deactivate slo...

Attributes
ACN	106796
Time
Date	198903
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : lhy
State Reference	PA
Altitude	msl bound lower : 28000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zny
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 100 flight time total : 15000 flight time type : 2800
ASRS Report	106796
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 203 flight time total : 8723 flight time type : 1850
ASRS Report	107012
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Climbing through 28000', first officer flying he advised me he had an elevator trim problem. We discovered the right trim handle (suitcase) jammed nose down. It could be moved with force, but snapped back to nose down when released. After going through the aircraft manual (no solution there!), and talking to system maintenance (no solution from them either!!), decided to return to departure airport because of good WX and long runway. Advised dispatch and after crew discussion, declared an emergency with center for flight control problem, asked for equipment stand by on landing and had F/a's prepare passenger for possible evacuate/evacuation. Dumped fuel to landing weight. Trim slowly creeping nose down, could get some nose up trim by electric trim. Experimented with gear and flaps: flap extension lessened the control forces to acceptable for approach and landing so we did not have to shut off hydraulic's and go to manual reversion for flight controller. Landing uneventful. The open crew discussion, using C.left.right. Training, was very helpful in solving problem, which was a double failure--a jammed trim clutch and leaking valve.

Original NASA ASRS Text

Title: ACR HVY HAD STAB TRIM PROBLEM DURING CLIMB. FLT CREW WAS UNABLE TO DEACTIVATE SLOW NOSE DOWN TRIM. RETURN LAND.

Narrative: CLBING THROUGH 28000', F/O FLYING HE ADVISED ME HE HAD AN ELEVATOR TRIM PROB. WE DISCOVERED THE RIGHT TRIM HANDLE (SUITCASE) JAMMED NOSE DOWN. IT COULD BE MOVED WITH FORCE, BUT SNAPPED BACK TO NOSE DOWN WHEN RELEASED. AFTER GOING THROUGH THE ACFT MANUAL (NO SOLUTION THERE!), AND TALKING TO SYS MAINT (NO SOLUTION FROM THEM EITHER!!), DECIDED TO RETURN TO DEP ARPT BECAUSE OF GOOD WX AND LONG RWY. ADVISED DISPATCH AND AFTER CREW DISCUSSION, DECLARED AN EMER WITH CENTER FOR FLT CTL PROB, ASKED FOR EQUIP STAND BY ON LNDG AND HAD F/A'S PREPARE PAX FOR POSSIBLE EVAC. DUMPED FUEL TO LNDG WT. TRIM SLOWLY CREEPING NOSE DOWN, COULD GET SOME NOSE UP TRIM BY ELECTRIC TRIM. EXPERIMENTED WITH GEAR AND FLAPS: FLAP EXTENSION LESSENED THE CONTROL FORCES TO ACCEPTABLE FOR APCH AND LNDG SO WE DID NOT HAVE TO SHUT OFF HYD'S AND GO TO MANUAL REVERSION FOR FLT CTLR. LNDG UNEVENTFUL. THE OPEN CREW DISCUSSION, USING C.L.R. TRNING, WAS VERY HELPFUL IN SOLVING PROB, WHICH WAS A DOUBLE FAILURE--A JAMMED TRIM CLUTCH AND LEAKING VALVE.

Data retrieved from NASA's ASRS site as of August 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.

Air carrier heavy had stabilizer trim problem during climb. Flight crew was unable to deactivate slow nose down trim. Return land.