A B737-800 DESCENDING FROM FL240 HAD ALTERNATE AND MAIN ELECTRIC STABILIZER TRIM FAIL. MANUAL TRIM OP OK. CAUSED BY FAILED ACTUATORS.

Narrative

I WAS FLYING THE ACFT FROM ZZZ TO ZZZ1. WHILE DSNDING FROM FL240 THE STAB OUT OF TRIM LIGHT ILLUMINATED. I ASKED THE FO TO RUN THE STABILIZER OUT OF TRIM CHKLIST. WE DID THE CHKLIST; HOWEVER; THE TRIM STILL DIDN'T WORK; SO THEN I ASKED FOR THE JAMMED STABILIZER CHKLIST. WE RAN THE JAMMED STABILIZER CHKLIST; I DECIDED TO DECLARE AN EMER BECAUSE WE WERE BEING VECTORED; WE WERE IN ICING CONDITIONS AND WE WERE GETTING CLOSER TO THE ARPT; USING MANUAL TRIM. BY DECLARING AN EMER WE WERE ABLE TO GET SET UP FOR A STRAIGHT IN THE APCH; AND FINISH THE JAMMED STABILIZER CHKLIST. WE WERE ABLE TO LAND FLAPS 15 WITH NO FURTHER PROBLEMS AND TAXIED TO THE GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED ON DSCNT THE STABILIZER OUT OF TRIM LIGHT CAME ON AND RAN CHKLIST AND THEN DISCOVERED THE MAIN ELECTRIC TRIM WOULD ALSO NOT WORK. THE RPTR SAID PER THE CHKLIST PROCS AN EMER WAS DECLARED AND AIRPLANE WAS TRIMMED USING THE MANUAL TRIM WHICH OPERATED NORMALLY. THE RPTR STATED MAINT REPLACED THE ALTERNATE TRIM ACTUATOR AND THE MAIN ELECTRIC TRIM ACTUATOR. THE RPTR STATED THE SAME AIRPLANE WAS FLOWN THE NEXT DAY ON A TRIP AND OPERATED NORMALLY.