A B737 DURING A HVY MAINT CHK THE FIRST OBSERVER'S SEAT WAS REPLACED. TECHNICIAN THAT REPLACED SEAT IS UNSURE IF PERSONAL BREATHING EQUIP WAS INSTALLED.

Narrative

I WAS WORKING COCKPIT/CABIN ON THE 'C' CHK OF ACFT. WE HAD AN UNUSUALLY LONG LIST OF NON ROUTINES FOR THE CABIN. I HAD ATTEMPTED TO REPAIR THE FIRST OBSERVER'S SEAT WHICH WOULD NOT LOCK IN THE 'DOWN' POS. FAILING TO CORRECT THE PROB WITH ADJUSTMENTS AND PARTS REPLACEMENT; I REPLACED THE SEAT ASSEMBLY A LITTLE AFTER XA00. I THEN CONCENTRATED ON FINISHING AS MANY OF THE REMAINING NON ROUTINE WRITE-UPS AS POSSIBLE BEFORE THE END OF THE SHIFT AT XB00. THE NEXT EVENING; SEP/TUE/06; WHEN COMING INTO WORK; I SAW THE FIRST OBSERVER'S SEAT I HAD REMOVED FROM #X ON THE TABLE OUTSIDE OF STORES. IT STILL HAD THE PBE MOUNTED TO IT. SOMETIMES NEW SEATS COME FROM STORES WITH A PBE ALREADY MOUNTED; SOMETIMES NOT. OBVIOUSLY I HAD NOT XFERRED THE PBE; BUT CANNOT REMEMBER IF ONE WAS ALREADY MOUNTED TO THE SEAT. WITH THE AMOUNT OF TIME I SPENT TRYING TO ADJUST/REPAIR THE ORIGINAL SEAT; AND THE HIGH QUANTITY OF NON ROUTINES IN THE CABIN; I WAS UNDER PRESSURE TO GET BACK TO THE NON ROUTINE LIST AND COMPLETE AS MUCH AS POSSIBLE BEFORE THE END OF THE SHIFT. THERE MAY IN FACT BE A PBE MOUNTED TO THE NEW SEAT ASSEMBLY; IN WHICH CASE THERE IS NO PROB.