FLT ATTENDANT NOTIFIES CREW OF SMOKE ALARM SOUNDING IN LAVATORY ON INITIAL CLB. RETURN LAND.

Narrative

JUST AFTER TKOF I RECEIVED A CALL FROM THE FLT ATTENDANT WHO INFORMED ME THAT THE LAVATORY SMOKE ALARM WAS SOUNDING OFF. THE REASON THAT I ANSWERED AS THE PF WAS THAT THE FO WAS SPEAKING TO ATC. EVERYONE TO INCLUDE THE CREW; ATC; AND THE PEOPLE ON THE GND DID THEIR JOB QUITE WELL. THE FO NOTIFIED ATC OF THE PROB; THE FLT ATTENDANT VERIFIED THERE WAS NO EVIDENCE OF FIRE AND HANDLED THE PEOPLE; AND I FLEW THE ACFT BACK TO THE ARPT. ONCE ON THE GND WE VISUALLY VERIFIED THAT NO DANGER EXISTED AND THAT THE BATTERY ON THE SMOKE DETECTOR WAS LOW. THIS IS WHERE I MADE A MISTAKE IN JUDGEMENT. I WENT INSIDE TO OPS TO NOTIFY COMPANY OF THE SIT. I WAS INFORMED THAT DISPATCH HAD ALREADY BEEN NOTIFIED. I FAILED TO SPEAK WITH MAINT. INSTEAD; I TOOK A NEW 9 VOLT BATTERY AND INSTALLED IT IN THE SMOKE DETECTOR AND WE CONTINUED TO OUR DEST. ONCE IN THE AIR I WAS NOTIFIED BY COMPANY THAT I HAD MADE A MISTAKE IN NOT WRITING UP THE SMOKE DETECTOR. THIS WAS ACCOMPLISHED AT OUR DEST WITH THE APPROPRIATE ACTIONS BY MAINT. MY ERROR IN JUDGEMENT WAS THAT I TREATED THE SMOKE DETECTOR NO DIFFERENTLY THAN A FLASHLIGHT. IT IN FACT NEEDS TO BE TREATED LIKE AN INTEGRAL PART OF THE ACFT.