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.