Narrative:

In descent to phl; we were given cross cofax at 25;000 ft. While descending for that we were given cross cofax at or below 25;000 ft; descend to 24;000 ft. I set 24;000 ft in MCP; but did not make the restriction 25;000 ft B in the box. Crossing cofax we were given a new crossing restriction of 20 west of lrp at 18;000 ft. This involved building a point prior to next point; which was bouhn. While putting that in; we missed that the aircraft did not continue the descent to 24;000 ft. ATC then pointed out to us that we needed to descend to 24;000 ft.

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Original NASA ASRS Text

Title: An air carrier flight crew missed a crossing restriction and then failed to descend on the PHL BUNTS ONE STAR because they were unfamiliar with new automation in their aircraft.

Narrative: In descent to PHL; we were given cross COFAX at 25;000 FT. While descending for that we were given cross COFAX at or below 25;000 FT; descend to 24;000 FT. I set 24;000 FT in MCP; but did not make the restriction 25;000 FT B in the box. Crossing COFAX we were given a new crossing restriction of 20 west of LRP at 18;000 FT. This involved building a point prior to next point; which was BOUHN. While putting that in; we missed that the aircraft did not continue the descent to 24;000 FT. ATC then pointed out to us that we needed to descend to 24;000 FT.

Data retrieved from NASA's ASRS site as of April 2012 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.