Narrative:

On a flight from bwi to bos we were given a clearance to cross 40 south of raalf at 24000 ft. The first officer programmed the FMC and I observed him enter the data correctly. After he had executed the entry, he changed a minor entry and I was not monitoring. About 25 mi south of raalf. ATC asked why we had not begun our descent. We immediately started our descent. Evidently, when the first officer reentered the data he erased the waypoint he had built to identify 40S raalf. We should have caught this problem but were not monitoring the flight path as we should have been. I believe one of the factors is our dependence on automation and not monitoring raw data, or just rechking entries into the FMC.

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Original NASA ASRS Text

Title: XING RESTR NOT MET.

Narrative: ON A FLT FROM BWI TO BOS WE WERE GIVEN A CLRNC TO CROSS 40 S OF RAALF AT 24000 FT. THE FO PROGRAMMED THE FMC AND I OBSERVED HIM ENTER THE DATA CORRECTLY. AFTER HE HAD EXECUTED THE ENTRY, HE CHANGED A MINOR ENTRY AND I WAS NOT MONITORING. ABOUT 25 MI S OF RAALF. ATC ASKED WHY WE HAD NOT BEGUN OUR DSCNT. WE IMMEDIATELY STARTED OUR DSCNT. EVIDENTLY, WHEN THE FO REENTERED THE DATA HE ERASED THE WAYPOINT HE HAD BUILT TO IDENT 40S RAALF. WE SHOULD HAVE CAUGHT THIS PROB BUT WERE NOT MONITORING THE FLT PATH AS WE SHOULD HAVE BEEN. I BELIEVE ONE OF THE FACTORS IS OUR DEPENDENCE ON AUTOMATION AND NOT MONITORING RAW DATA, OR JUST RECHKING ENTRIES INTO THE FMC.

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.