Narrative:

IFR cleared to descent from 5;000 to 4;000 direct my destination. Advised by phl TRACON traffic 12:00 expedite descent. Went to 1;000 ft per minute. TCAS announcing 'traffic' 'traffic'. Painted target at 2 miles at 4;000 ft. Continued descent to 3;700 and leveled. Traffic passed directly over at 3;900 ft. Advised TRACON had descended to 3;700 to avoid traffic. Phl TRACON advised were only cleared to 4;000 and requested return to 4;000. Did so. Flight terminated as planned.

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Original NASA ASRS Text

Title: A single engine pilot reported a near miss after PHL TRACON issued a traffic alert during a descent to 4;000 FT. The reporter descended to 3;700 FT to evade the traffic.

Narrative: IFR cleared to descent from 5;000 to 4;000 direct my destination. Advised by PHL TRACON traffic 12:00 expedite descent. Went to 1;000 FT per minute. TCAS announcing 'traffic' 'traffic'. Painted target at 2 miles at 4;000 FT. Continued descent to 3;700 and leveled. Traffic passed directly over at 3;900 FT. Advised TRACON had descended to 3;700 to avoid traffic. PHL TRACON advised were only cleared to 4;000 and requested return to 4;000. Did so. Flight terminated as planned.

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.