B727 crew undershoot cleared altitude.

Attributes
ACN	450629
Time
Date	199909
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : swl.vortac
State Reference	MD
Altitude	msl bound lower : 15000 msl bound upper : 16000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : vacating altitude
Route In Use	arrival star : cedar lake 7
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	450629
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
ASRS Report	450630
Events
Anomaly	altitude deviation : undershoot non adherence : published procedure non adherence : far non adherence : company policies non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to original clearance flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Altitude deviation. At FL240 on the cedar lake 7 arrival into phl, center gave us a clearance to cross radds intersection at 15000 ft. 15000 ft was set into the altitude alerter and we started our descent out of FL240. We got into a discussion about checklist procedures and at 17000 ft I announced 17000 ft for 16000 ft. I proceeded to level off at 16000 ft. 5 mi north of radds intersection, controller questioned our clearance. I then descended to 15000 ft as previously cleared. Just a plain old lack of concentration on my part. No other traffic in area. Supplemental information from acn 450628: at FL240 on the cedar lake 7 arrival into phl, center gave us a clearance to cross radds intersection at 15000 ft. 15000 ft was selected in the altitude alert and captain initiated our descent out of FL240. We got into a discussion about our checklist procedures. 5 mi north of radds, the controller queried our clearance because we had leveled off at 16000 ft. The captain descended to 15000 ft as previously cleared. It was not the time or place to have this discussion -- while we were descending into the terminal area. I should have paid closer attention, and not been diverted from maintaining my situational awareness. No conflicting traffic in the area.

Original NASA ASRS Text

Title: 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.

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.