Altimeter disagreement of 500' leads to altitude deviation.

Attributes
ACN	141187
Time
Date	199004
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den
State Reference	CO
Altitude	msl bound lower : 10500 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : instrument pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 2500 flight time type : 800
ASRS Report	141187
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 110 flight time total : 3200 flight time type : 90
ASRS Report	141189
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Arriving den we were turning and leveling in turbulence, when approach called we were 500' low, the first officer's altimeter was indicating improperly. Maintenance action was taken. Supplemental information from acn 141189. When arriving in denver area, approach told us we were 500' low. We were in a turn and leveling in turbulence. The first officer's altimeter was sticking high and not indicating properly. We were in the process of correcting at the time we were notified by ATC. Maintenance action was taken.

Original NASA ASRS Text

Title: ALTIMETER DISAGREEMENT OF 500' LEADS TO ALT DEVIATION.

Narrative: ARRIVING DEN WE WERE TURNING AND LEVELING IN TURB, WHEN APCH CALLED WE WERE 500' LOW, THE F/O'S ALTIMETER WAS INDICATING IMPROPERLY. MAINT ACTION WAS TAKEN. SUPPLEMENTAL INFO FROM ACN 141189. WHEN ARRIVING IN DENVER AREA, APCH TOLD US WE WERE 500' LOW. WE WERE IN A TURN AND LEVELING IN TURB. THE F/O'S ALTIMETER WAS STICKING HIGH AND NOT INDICATING PROPERLY. WE WERE IN THE PROCESS OF CORRECTING AT THE TIME WE WERE NOTIFIED BY ATC. MAINT ACTION WAS TAKEN.

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.