ACFT OPERATED WITHOUT FLT RECORDER. VIOLATION OF FAR'S.

Narrative

WE HAD JUST FINISHED A 2 DAY TRIP IN SFO WITH MYSELF FLYING AS A FO IN ACFT. (CURRENTLY CAPT QUALIFIED). I THEN SWITCHED TO L SEAT AS CAPT; WITH A NEW PLT AS FO; AND FLEW THE SAME ACFT FROM SFO TO SBA AND RETURN; WHICH COMPLETED MY FLYING FOR THE DAY. I WAS LATER INFORMED THAT THE CAPT WHICH I FLEW WITH ON MAR/SAT/92 HAD NOT TAKEN NOTICE OF AN OPEN MECHANICAL ENTRY IN THE FLT LOG BY THE PREVIOUS PLT OF THAT ACFT. THE ENTRY WAS FOR AN INOP FLT DATA RECORDER. I HAD SIMILARLY MISSED THE OPEN ENTRY THE NEXT DAY WHEN I TOOK OVER AS CAPT; AS HAD THE NEXT CAPT AFTER MYSELF. THE PSYCHOLOGY OF TRANSFERRING FROM R SEAT TO L SEAT ON THE SAME ACFT HAD NO DOUBT AFFECTED THE THOROUGHNESS OF MY PREFLT DUTIES WHEN I SWITCHED SEATS (UNFORTUNATELY; THE USE OF CAPTS TO FLY AS FO'S IS BEING DONE ON A REGULAR BASIS BY THIS AIRLINE; WITH LITTLE REGARD AS TO HOW THIS SITUATION AFFECTS THE EFFECTIVENESS OF THE CREW AS A TEAM). SWITCHING ROLES FROM CAPT TO FO AND BACK TO CAPT AGAIN IN SO SHORT A TIME SPAN CONFLICTED AND INTERFERED WITH MY CAPT'S ROLES OF JUDGEMENT AND RESPONSIBILITY.