Air carrier turbojet aircraft overshot altitude on descent in ZAU airspace.

Attributes
ACN	417550
Time
Date	199810
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sbn
State Reference	IN
Altitude	msl bound lower : 14600 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tower : lit
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 2000
ASRS Report	417550
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Descended 400 ft below assigned altitude, corrected to proper altitude within 30 seconds. Was distraction by 3 separate traffic calls from center also monitoring TCASII.

Original NASA ASRS Text

Title: ACR TURBOJET ACFT OVERSHOT ALT ON DSCNT IN ZAU AIRSPACE.

Narrative: DSNDED 400 FT BELOW ASSIGNED ALT, CORRECTED TO PROPER ALT WITHIN 30 SECONDS. WAS DISTR BY 3 SEPARATE TFC CALLS FROM CTR ALSO MONITORING TCASII.

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.