Narrative:

Were given a slam dunk approach to runway 22R at ord. While trying to descend to capture the GS from above, forgot to arm the approach mode. At approximately 1200 ft, descended below the GS about 2 dots. Leveled off and recaptured the GS at about 500 ft. Airplane was on target speed and fully configured. All checklists were completed. Contributing factors were the close-in vector from a high altitude given by ATC, fatigue from a trip with lots of WX, the mix of international and domestic operations, night flying, and poor sleep the night before during a short layover, shortened by a delay in xportation to the hotel, and long term fatigue from months of arduous schedules, long days and lack of time off.

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Original NASA ASRS Text

Title: AN A319 CAPT RPTED THAT HE FORGOT TO ARM THE APCH FOR ORD WHILE HIS FO WAS FLYING, CAUSING AN ALT OVERSHOOT THAT WAS RECOVERED AT 500 FT.

Narrative: WERE GIVEN A SLAM DUNK APCH TO RWY 22R AT ORD. WHILE TRYING TO DSND TO CAPTURE THE GS FROM ABOVE, FORGOT TO ARM THE APCH MODE. AT APPROX 1200 FT, DSNDED BELOW THE GS ABOUT 2 DOTS. LEVELED OFF AND RECAPTURED THE GS AT ABOUT 500 FT. AIRPLANE WAS ON TARGET SPD AND FULLY CONFIGURED. ALL CHKLISTS WERE COMPLETED. CONTRIBUTING FACTORS WERE THE CLOSE-IN VECTOR FROM A HIGH ALT GIVEN BY ATC, FATIGUE FROM A TRIP WITH LOTS OF WX, THE MIX OF INTL AND DOMESTIC OPS, NIGHT FLYING, AND POOR SLEEP THE NIGHT BEFORE DURING A SHORT LAYOVER, SHORTENED BY A DELAY IN XPORTATION TO THE HOTEL, AND LONG TERM FATIGUE FROM MONTHS OF ARDUOUS SCHEDULES, LONG DAYS AND LACK OF TIME OFF.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.