B727 CREW UNDERSHOOT CLRED ALT.

Narrative

ALTDEV. AT FL240 ON THE CEDAR LAKE 7 ARR INTO PHL; CTR GAVE US A CLRNC TO CROSS RADDS INTXN AT 15000 FT. 15000 FT WAS SET INTO THE ALT ALERTER AND WE STARTED OUR DSCNT OUT OF FL240. WE GOT INTO A DISCUSSION ABOUT CHKLIST PROCS AND AT 17000 FT I ANNOUNCED 17000 FT FOR 16000 FT. I PROCEEDED TO LEVEL OFF AT 16000 FT. 5 MI N OF RADDS INTXN; CTLR QUESTIONED OUR CLRNC. I THEN DSNDED TO 15000 FT AS PREVIOUSLY CLRED. JUST A PLAIN OLD LACK OF CONCENTRATION ON MY PART. NO OTHER TFC IN AREA. SUPPLEMENTAL INFO FROM ACN 450628: AT FL240 ON THE CEDAR LAKE 7 ARR INTO PHL; CTR GAVE US A CLRNC TO CROSS RADDS INTXN AT 15000 FT. 15000 FT WAS SELECTED IN THE ALT ALERT AND CAPT INITIATED OUR DSCNT OUT OF FL240. WE GOT INTO A DISCUSSION ABOUT OUR CHKLIST PROCS. 5 MI N OF RADDS; THE CTLR QUERIED OUR CLRNC BECAUSE WE HAD LEVELED OFF AT 16000 FT. THE CAPT DSNDED TO 15000 FT AS PREVIOUSLY CLRED. IT WAS NOT THE TIME OR PLACE TO HAVE THIS DISCUSSION -- WHILE WE WERE DSNDING INTO THE TERMINAL AREA. I SHOULD HAVE PAID CLOSER ATTN; AND NOT BEEN DIVERTED FROM MAINTAINING MY SITUATIONAL AWARENESS. NO CONFLICTING TFC IN THE AREA.