Altitude overshoot with wrong altimeter setting.

Attributes
ACN	490160
Time
Date	200010
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : cofax
State Reference	PA
Altitude	msl bound lower : 24700 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tower : ilm.tower
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 12000 flight time type : 600
ASRS Report	490160
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Clearance to cross cofax intersection at FL250. During descent altimeter was inadvertently set to qnh instead of 29.92 causing our aircraft to cross cofax approximately 300 ft low. We reset altimeter to 29.92 and climbed back to FL250 approximately 1 mi after cofax.

Original NASA ASRS Text

Title: ALT OVERSHOOT WITH WRONG ALTIMETER SETTING.

Narrative: CLRNC TO CROSS COFAX INTXN AT FL250. DURING DSCNT ALTIMETER WAS INADVERTENTLY SET TO QNH INSTEAD OF 29.92 CAUSING OUR ACFT TO CROSS COFAX APPROX 300 FT LOW. WE RESET ALTIMETER TO 29.92 AND CLBED BACK TO FL250 APPROX 1 MI AFTER COFAX.

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.