A DC9-30 flight crew descending into stl went below assigned altitude.

Attributes
ACN	433630
Time
Date	199904
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : stl.vortac
State Reference	IN
Altitude	msl single value : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : t75.tracon
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Navigation In Use	Other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp
Experience	flight time last 90 days : 120 flight time total : 14500 flight time type : 650
ASRS Report	433630
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 7000 flight time type : 500
ASRS Report	434831
Events
Anomaly	altitude deviation : overshoot
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned airspace
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While descending to 7000 ft, first officer overshot altitude by 300 ft. Lowest altitude was 6700 ft. Both pilots were occupied with approach set up when deviation occurred. Supplemental information from acn 434831: I was reviewing approach plate when I descended below 7000 ft to 6700 ft. Returned to cleared altitude.

Original NASA ASRS Text

Title: A DC9-30 FLC DSNDING INTO STL WENT BELOW ASSIGNED ALT.

Narrative: WHILE DSNDING TO 7000 FT, FO OVERSHOT ALT BY 300 FT. LOWEST ALT WAS 6700 FT. BOTH PLTS WERE OCCUPIED WITH APCH SET UP WHEN DEV OCCURRED. SUPPLEMENTAL INFO FROM ACN 434831: I WAS REVIEWING APCH PLATE WHEN I DSNDED BELOW 7000 FT TO 6700 FT. RETURNED TO CLRED ALT.

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.