S80 flight overshoots the assigned altitude by 300 ft.

Attributes
ACN	462890
Time
Date	200002
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ord.vor
State Reference	IL
Altitude	msl bound lower : 6700 msl bound upper : 7000
Aircraft 1
Controlling Facilities	tracon : c90.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
ASRS Report	462890
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	463540
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Deviated 300 ft below assigned altitude of 7000 ft when copilot mistakenly assumed assigned altitude to be 6000 ft. Corrected by captain and rapidly corrected to 7000 ft. Supplemental information from acn 463540: ATC said nothing and we observed no conflict with any traffic. Distraction was the main cause of the deviation. Multiple radio calls -- altitude changes and speed changes.

Original NASA ASRS Text

Title: S80 FLT OVERSHOOTS THE ASSIGNED ALT BY 300 FT.

Narrative: DEVIATED 300 FT BELOW ASSIGNED ALT OF 7000 FT WHEN COPLT MISTAKENLY ASSUMED ASSIGNED ALT TO BE 6000 FT. CORRECTED BY CAPT AND RAPIDLY CORRECTED TO 7000 FT. SUPPLEMENTAL INFO FROM ACN 463540: ATC SAID NOTHING AND WE OBSERVED NO CONFLICT WITH ANY TFC. DISTR WAS THE MAIN CAUSE OF THE DEV. MULTIPLE RADIO CALLS -- ALT CHANGES AND SPD CHANGES.

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.