Altitude deviation altitude overshot.

Attributes
ACN	317778
Time
Date	199510
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pmm
State Reference	MI
Altitude	msl bound lower : 8700 msl bound upper : 9000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dsm
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other
Route In Use	arrival other enroute : direct enroute airway : ord
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 13300
ASRS Report	317778
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time total : 2800
ASRS Report	317780
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Altitude deviation. Descended 300 ft below assigned altitude due to altimeter problems and the heavy workload on both pilots.

Original NASA ASRS Text

Title: ALTDEV ALT OVERSHOT.

Narrative: ALT DEVIATION. DSNDED 300 FT BELOW ASSIGNED ALT DUE TO ALTIMETER PROBS AND THE HVY WORKLOAD ON BOTH PLTS.

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.