Return land mandated by loss of horizontal stabilizer control trim in a dc-10.

Attributes
ACN	295634
Time
Date	199502
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sfo
State Reference	CA
Altitude	msl bound lower : 27000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa tower : avl
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 25000 flight time type : 11000
ASRS Report	295634
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 180 flight time total : 12000
ASRS Report	295633
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

After takeoff right wing heavy required 4 degrees aileron trim. At cruise lost elevator trim. Used control wheel steering to lessen back pressure. Dumped 20000 pounds of fuel, slow flight tested with gear and flaps down, declared an emergency, and prepared cabin for an evacuate/evacuation. Landed without incident. Cause was load feel mechanism improperly installed and resultant failure of stabilizer shear pin. Supplemental information from acn 295633: trip departed approximately 30 mins late due to cabin maintenance. Aircraft just completed 'C' maintenance check. During climb, nose became heavy and long. Trim inoperative (yoke switch, altitude trim switch, and autoplt). Surface position indicator, elevator was split. Left index 1 increment below the right. Rudder was 1 increment to the right. Reviewed jammed stabilizer irregular and attempted unsuccessfully to call maintenance. Dumped approximately 18000 pounds of fuel, planned landing weight approximately 345000 pounds. At 7000 ft, we leveled the aircraft and lowered the gear and flaps to check the ctlability of the aircraft. The captain and I both participated in this maneuver. The nose was extremely heavy, but ctlable. We also tried flying the aircraft with both the autoplt and cws. This was satisfactory and we elected to leave cws on, because of the excessive control forces.

Original NASA ASRS Text

Title: RETURN LAND MANDATED BY LOSS OF HORIZ STABILIZER CTL TRIM IN A DC-10.

Narrative: AFTER TKOF R WING HVY REQUIRED 4 DEGS AILERON TRIM. AT CRUISE LOST ELEVATOR TRIM. USED CTL WHEEL STEERING TO LESSEN BACK PRESSURE. DUMPED 20000 LBS OF FUEL, SLOW FLT TESTED WITH GEAR AND FLAPS DOWN, DECLARED AN EMER, AND PREPARED CABIN FOR AN EVAC. LANDED WITHOUT INCIDENT. CAUSE WAS LOAD FEEL MECHANISM IMPROPERLY INSTALLED AND RESULTANT FAILURE OF STABILIZER SHEAR PIN. SUPPLEMENTAL INFO FROM ACN 295633: TRIP DEPARTED APPROX 30 MINS LATE DUE TO CABIN MAINT. ACFT JUST COMPLETED 'C' MAINT CHK. DURING CLB, NOSE BECAME HVY AND LONG. TRIM INOP (YOKE SWITCH, ALT TRIM SWITCH, AND AUTOPLT). SURFACE POS INDICATOR, ELEVATOR WAS SPLIT. L INDEX 1 INCREMENT BELOW THE R. RUDDER WAS 1 INCREMENT TO THE R. REVIEWED JAMMED STABILIZER IRREGULAR AND ATTEMPTED UNSUCCESSFULLY TO CALL MAINT. DUMPED APPROX 18000 LBS OF FUEL, PLANNED LNDG WT APPROX 345000 LBS. AT 7000 FT, WE LEVELED THE ACFT AND LOWERED THE GEAR AND FLAPS TO CHK THE CTLABILITY OF THE ACFT. THE CAPT AND I BOTH PARTICIPATED IN THIS MANEUVER. THE NOSE WAS EXTREMELY HVY, BUT CTLABLE. WE ALSO TRIED FLYING THE ACFT WITH BOTH THE AUTOPLT AND CWS. THIS WAS SATISFACTORY AND WE ELECTED TO LEAVE CWS ON, BECAUSE OF THE EXCESSIVE CTL FORCES.

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.