B737 FLC FORGETS TO RESET THEIR ALTIMETERS AND OVERSHOT THEIR ASSIGNED ALT.

Narrative

DURING CLBOUT; THE FLT WAS RESTR TO 17000 FT. AFTER CRUISING FOR A FEW MINS AT THIS ALT; WE WERE CLRED TO FL230 AND DIRECT TO PSK. CLB WAS INITIATED AND DIVERTED ATTN TO LOCATING PSK FREQ ON CHART. AFTER LEVELING OFF AT FL230; 1 OR 2 MORE STEP-CLBS WERE ISSUED TO FL290. WHILE CRUISING AT FL290; ATC INQUIRED ABOUT OUR ALT AND I RESPONDED FL290; AS INDICATED ON ALL 3 ALTIMETERS. WE WERE THEN CLRED TO FL310. AS CLB WAS INITIATED TO FL310; I REALIZED THAT ALL 3 ALTIMETERS WERE STILL SET TO QNH RATHER THAN QNE (29.92). THE ALTIMETERS WERE THEN RESET TO 29.92 AND THE FLT CONTINUED CLBING TO FL310; WHERE IT CRUISED. THE CAUSE OF MISSING THE RESETTING OF THE ALTIMETERS PASSING FL180 WAS THE DISTR OF SEARCHING FOR THE VOR FREQ; WHICH OCCURRED WHILE CLBING BTWN 17000 FT AND FL180. CONTINUING FACTORS WERE: FATIGUE (THIS FLT BROUGHT ME WITHIN 15 MINS OF ACCUMULATING 30 HRS IN 5 DAYS; UNDER VERY ADVERSE CONDITIONS) AND; INEXPERIENCED FO (NEW TO THE COMPANY AND ON THE ACFT). A POSSIBLE ERROR TRAPPING COULD HAVE OCCURRED HAD THE CTLR MENTIONED THE DISCREPANCY IN MODE C (ESTIMATED AT 300 FT) WHEN WE HAD LEVELED OFF 2 OR 3 TIMES BEFORE AND AFTER REACHING FL290. HIS INQUIRY ABOUT OUR ALT DID NOT TRIGGER ANY SUSPICION SINCE ALL 3 ALTIMETERS INDICATED THE SAME ALT (FL290). IT HAS BEEN MY EXPERIENCE IN THE LAST FEW YRS THAT ATC ISSUES COMPOSITE CLRNCS QUITE OFTEN (ALT; HDG; AIRSPD; ETC). THIS; COMBINED WITH 4-DIGIT FLT NUMBERS; LEADS TO CONFUSION AND ADDS A LINK TO THE POSSIBLE ERROR CHAIN. ADDITIONALLY; WHEN SUCH CLRNCS COME AT MOMENTS; WHEN OTHERWISE ROUTINE HABIT PATTERNS ARE INTERRUPTED; THE POSSIBILITY OF AN UNTRAPPED ERROR IS GREATLY INCREASED. INTRODUCE TO THIS CHAIN FATIGUE AND INEXPERIENCE; AND THEN WE HAVE AN ENVIRONMENT IN WHICH THE HUMAN FACTOR ERROR REACHES IT GREATEST POTENTIAL. AS FOR THIS PARTICULAR ERROR (ALTIMETER SETTING); I PLAN TO RECHK THE SETTING SEVERAL TIMES AFTER PASSING FL180; NOT ONLY WHEN I COME THROUGH IT.