A B737 CAPT INADVERTENTLY CLOSED THE COCKPIT DOOR BEFORE LETTING THE FLT ATTENDANT IN WHEN USING THE RESTROOM. THE FO HAD TO USE THE ELECTRONIC DOOR OPENER WHICH WAS AGAINST COMPANY POLICY.

Narrative

AFTER HAVING FLOWN 80 HRS IN THE LAST 30 DAYS AND HAVING SPENT 20 HRS IN THE COCKPIT IN THE PRECEDING 3 DAY PERIOD; I WAS ON A NIGHT LEG; IN CRUISE; AND ELECTED TO PROCEED FROM THE COCKPIT TO USE THE LAVATORY PRIOR TO DSCNT. AS I LEFT THE COCKPIT; I WAS DISTR BY ENGAGING IN A CONVERSATION WITH THE #1 FLT ATTENDANT REGARDING AN ISSUE/CONFLICT BTWN HERSELF AND THE FO. AS I STEPPED OUT OF THE COCKPIT; I ABSENTMINDEDLY CLOSED THE COCKPIT DOOR; WITHOUT ALLOWING A FLT ATTENDANT INTO THE COCKPIT AS PER SECURITY PROCS. AFTER STABILIZING VOICE COM WITH THE FO VIA THE INTERPHONE; HE WAS FORCED TO USE THE ELECTRONIC ACCESS SWITCH (UNLOCK POS) TO OPEN THE DOOR AND ALLOW ME RE-ENTRY INTO THE COCKPIT. USE OF THE SWITCH IN THIS MANNER IS ALSO PROHIBITED BY OUR PROCS. ALTHOUGH I CONSIDER MYSELF TO BE EXTREMELY SECURITY CONSCIOUS; I CONTRIBUTE THIS BREACH TO A COMBINATION OF: FATIGUE; DISTR AND A REVERSION TO OLD HABIT PATTERNS. THE FATIGUE DUE TO TIME OF DAY AND NUMBER OF FLT HRS IN A SHORT TIME SPAN; THE DISTR OF THE CONVERSATION WITH THE FLT ATTENDANT; AND IN MY FATIGUED STATE I REVERTED TO AN OLD HABIT PATTERN IN THAT THE MAJORITY OF MY EXPERIENCE WAS ON A 3 MAN CREW; B727 WHERE POSITIONING OF A FLT ATTENDANT IN THE COCKPIT DURING MY ABSENCE WAS NOT NECESSARY. LASTLY; I WAS DEALING WITH AN ACUTE FAMILY HEALTH CRISIS AT HOME WHICH WAS EMOTIONALLY DISTRESSFUL. THIS EVENT DEMONSTRATED TO ME HOW IMPORTANT IT IS THAT I MAINTAIN A CONSTANT SITUATIONAL AWARENESS TO BOTH FLYING AND NON FLYING ISSUES WHILE IN COMMAND OF THE ACFT; AND TO CONTINUALLY EVALUATE MY OWN MENTAL ALERTNESS AND PHYSICAL WELL BEING PRIOR TO ACCEPTING FLT DUTIES.