AN ACR DC9 FLC DSNDED THROUGH THEIR ASSIGNED ALT. THE CAPT FEELS THAT FATIGUE PLAYED A PART AND THE FO WAS DISTR BY ANOTHER DUTY AT THE TIME.

Narrative

WE WERE DSNDING INTO CLT WITH A CLRNC OF 9000 FT. THE FO MADE HIS CALLOUT OF 10000 FT FOR 9000 FT; WHICH I ACKNOWLEDGED AND I CALLED 'OUT OF 10000 FT; LIGHT ON; APCH CHKLIST.' HE ACCOMPLISHED THE CHKLIST AND THE NEXT THING I REMEMBER WAS THE ALT ALERTER GOING OFF. I CHKED MY ALT AT 8700 FT; CHKED THE ALERTER SET AT 9000 FT AND CLBED IMMEDIATELY TO 9000 FT. THE CTLR ASKED WHAT OUR ALT WAS AS WE ARRIVED BACK AT 9000 FT. A SHORT WHILE LATER HE POINTED OUT CONVERGING TFC AT 8000 FT AND 3 MI. AT THE TIME OF THE EXCURSION; I DON'T THINK WE HAD A TFC CONFLICT. I THINK FATIGUE WAS A FACTOR IN THIS EVENT. DUE TO LABOR PROBS AT OUR AIRLINE; THIS WAS MY 13TH CONSECUTIVE DAY OF WORK AND THE 9TH BACK SIDE OF THE CLOCK OP. (TWICE DURING THIS PERIOD I HAD APPROX A 60 HR BREAK WITHOUT DUTY.) ADDITIONALLY; I HAD WORKED 21 OF THE LAST 23 DAYS. I REMEMBER THE ALERTER AS TOTAL SHOCK; LIKE AN ALARM WAKING ME UP. I'M SURE I WASN'T ASLEEP; BUT I THINK MY 'LIGHTS WERE ON; AND NOBODY WAS HOME.' SOMETIMES THE XA00-XC00 TIME PERIOD IS A BAD TIME FOR ME AND I THINK TOO MUCH WORK HAS AGGRAVATED IT. I'LL JUST HAVE TO BE MORE CAREFUL TO PREVENT A RECURRENCE. MY VACATION IS CLOSE; AND I'LL BE TAKING CARE OF ANY SLEEP DEFICIT.