Altitude overshoot near atlanta city. Autoflt system questioned.

Attributes
ACN	490760
Time
Date	200010
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : acy.vortac
State Reference	NJ
Altitude	msl bound lower : 6600 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : acy.tracon tower : ilg.tower
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 180 flight time total : 6000 flight time type : 4000
ASRS Report	490760
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Events
Anomaly	altitude deviation : overshoot non adherence : company policies non adherence : clearance
Independent Detector	aircraft equipment : altitude alert other controllerb
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to 7000 ft by acy approach control en route to phl. The autoplt flight director altitude capture mode didn't capture and we didn't note its failure to leveloff at 7000 ft. ATC called us at the same time the altitude alerter sounded at 6600 ft, and cleared us to 4000 ft. We climbed back up to 6700 ft, and ATC asked us our altitude. We stated 6700 ft, then read back the clearance and descended to 4000 ft. We were distracted looking for traffic and missed our SOP call of 'level 7000 ft.' had we made the call, we would nave noticed the impending deviation.

Original NASA ASRS Text

Title: ALT OVERSHOOT NEAR ATLANTA CITY. AUTOFLT SYS QUESTIONED.

Narrative: WE WERE CLRED TO 7000 FT BY ACY APCH CTL ENRTE TO PHL. THE AUTOPLT FLT DIRECTOR ALT CAPTURE MODE DIDN'T CAPTURE AND WE DIDN'T NOTE ITS FAILURE TO LEVELOFF AT 7000 FT. ATC CALLED US AT THE SAME TIME THE ALT ALERTER SOUNDED AT 6600 FT, AND CLRED US TO 4000 FT. WE CLBED BACK UP TO 6700 FT, AND ATC ASKED US OUR ALT. WE STATED 6700 FT, THEN READ BACK THE CLRNC AND DSNDED TO 4000 FT. WE WERE DISTRACTED LOOKING FOR TFC AND MISSED OUR SOP CALL OF 'LEVEL 7000 FT.' HAD WE MADE THE CALL, WE WOULD NAVE NOTICED THE IMPENDING DEV.

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.