ALTDEV ALT OVERSHOT IN DSCNT PROC.

Narrative

CHK-IN TIME FOR FLT WAS AT XA00; A DELAY OF 7 HRS. THIS HAD BEEN PUSHED BACK FROM XB00 DUE TO A SNOW STORM. THE FLT FROM JFK TO CUN WAS NORMAL; ON RETURN; FATIGUE BEGAN TO SET IN. THE CAPT PICKED UP THE ATIS WHILE STILL IN CRZ. AFTER DSCNT I PICKED UP THE ATIS AND VERIFIED IT WAS THE SAME ONE THE CAPT HAD. I VERIFIED IT ONLY BY LETTER 'B' AND DID NOT DO A FULL READ; LIKE I NORMALLY WOULD. PASSING 18000 FT IN DSCNT THE CAPT (PF) SET HIS ALTIMETERS; I SET MINE THE SAME AS HIS; WITHOUT CHKING MY NOTES FROM THE ATIS. THE CAPT HAD SET HIS ALTIMETER TO THE WIND 300 DEG AT 19 KTS ON HIS NOTE PAD 300.19 SO HE SET 30.19. THE CORRECT SETTING WAS 29.40 OR SOMETHING I DON'T REMEMBER IT NOW. ATC HAD US CROSS CAMRN AT 11000 FT AS ON THE STAR CAMRN 2 ARR. WHEN WE LEVELED AT 11000 FT THE CTLR CALLED AND SAID WE WERE AT 10300 FT. WE ASKED FOR THE ALTIMETER SETTING AS WE SHOWED 11000 FT. HE GAVE IT TO US AND WE DISCOVERED OUR MISTAKE. WE HAD BEEN FLYING FROM XC00 TO XD00 IN THE MORNING. EVEN THOUGH I HEARD THE CORRECT SETTING ON THE ATIS AND THE CTLR GAVE US THE SETTING AT THE BEGINNING OF DSCNT I DID NOT RECOGNIZE THE CAPT'S MISTAKE. I THINK FATIGUE HAD A LOT TO DO WITH THIS. WE SHOULD HAVE XCHKED THE CAPT'S NOTES WITH MIND AND OR THE SETTING GIVEN BY ATC. ATC GAVE US THE SETTING AT THE END OF A DSCNT CLRNC; AND IT WAS MORE THAN I COULD REMEMBER BEING SO TIRED. MAYBE ATC CAN GIVE THE SETTING WHEN PASSING 18000 FT. I FEEL FATIGUE WAS THE MAJOR CAUSE OF THIS CASE.