Narrative:

We were cleared to descend to maintain 12,000' from 18,000' while on the lendy arrival to jfk. We descended through 12,000' and the captain and first officer caught I passing through 11,500'. Recovery to assigned altitude was immediately started. Center said very little. Lowest altitude in the deviation was 11,350'. (What a shock it all was!) the first officer had set and armed the altitude alert box (he was flying) but was not using the flight director, so the altitude was not armed. The captain was looking outside and was not using the flight director. The altitude alert box is somewhat difficult to clearly see from the captain's side of cockpit.

Google
 

Original NASA ASRS Text

Title: AIR CARRIER WITH FO RECENT RETURN TO DUTY AND HEW HIRE SO OVERSHOOTS ALT IN DESCENT.

Narrative: WE WERE CLRED TO DSND TO MAINTAIN 12,000' FROM 18,000' WHILE ON THE LENDY ARR TO JFK. WE DESCENDED THROUGH 12,000' AND THE CAPT AND F/O CAUGHT I PASSING THROUGH 11,500'. RECOVERY TO ASSIGNED ALT WAS IMMEDIATELY STARTED. CENTER SAID VERY LITTLE. LOWEST ALT IN THE DEVIATION WAS 11,350'. (WHAT A SHOCK IT ALL WAS!) THE F/O HAD SET AND ARMED THE ALT ALERT BOX (HE WAS FLYING) BUT WAS NOT USING THE FLT DIRECTOR, SO THE ALT WAS NOT ARMED. THE CAPT WAS LOOKING OUTSIDE AND WAS NOT USING THE FLT DIRECTOR. THE ALT ALERT BOX IS SOMEWHAT DIFFICULT TO CLEARLY SEE FROM THE CAPT'S SIDE OF COCKPIT.

Data retrieved from NASA's ASRS site as of August 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.