CL65 captain overshot approach intermediate altitude due to wrong altimeter setting.

Attributes
ACN	531275
Time
Date	200111
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dsm.airport
State Reference	IA
Altitude	agl bound lower : 700 agl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : dsm.tracon tower : btv.tower
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 31
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 230 flight time total : 8200 flight time type : 1500
ASRS Report	531275
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : published procedure non adherence other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : altimeter setting 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:

We were cleared to 2400 ft until establish on a published portion of the approach, cleared for ILS runway 31 (dsm). I made a slow descent, so I could try and intercept the GS. First officer called field in sight approximately 10 NM from field. Leveled off at 2400 ft and I was still below GS. (Radar altimeter read 700 ft.) told my first officer that something was not right and it was rather low for being outside OM. First officer said 'well, you're right, but you're at 1500 ft.' I had 2500 ft. I asked again what the altimeter setting was and found that I have 30.36 and my first officer had 29.36. During the checklist we set altimeters. I called '30.36 set right.' first officer called altimeter for her side as well as stand by. Never caught the difference in settings. While descending through 3400 ft (actual 2400 ft) I stated '1000 ft to level off.' first officer never questioned the call, even though her altimeter was reading correct altitude of 2400 ft.

Original NASA ASRS Text

Title: CL65 CAPT OVERSHOT APCH INTERMEDIATE ALT DUE TO WRONG ALTIMETER SETTING.

Narrative: WE WERE CLRED TO 2400 FT UNTIL ESTABLISH ON A PUBLISHED PORTION OF THE APCH, CLRED FOR ILS RWY 31 (DSM). I MADE A SLOW DSCNT, SO I COULD TRY AND INTERCEPT THE GS. FO CALLED FIELD IN SIGHT APPROX 10 NM FROM FIELD. LEVELED OFF AT 2400 FT AND I WAS STILL BELOW GS. (RADAR ALTIMETER READ 700 FT.) TOLD MY FO THAT SOMETHING WAS NOT RIGHT AND IT WAS RATHER LOW FOR BEING OUTSIDE OM. FO SAID 'WELL, YOU'RE RIGHT, BUT YOU'RE AT 1500 FT.' I HAD 2500 FT. I ASKED AGAIN WHAT THE ALTIMETER SETTING WAS AND FOUND THAT I HAVE 30.36 AND MY FO HAD 29.36. DURING THE CHKLIST WE SET ALTIMETERS. I CALLED '30.36 SET R.' FO CALLED ALTIMETER FOR HER SIDE AS WELL AS STAND BY. NEVER CAUGHT THE DIFFERENCE IN SETTINGS. WHILE DSNDING THROUGH 3400 FT (ACTUAL 2400 FT) I STATED '1000 FT TO LEVEL OFF.' FO NEVER QUESTIONED THE CALL, EVEN THOUGH HER ALTIMETER WAS READING CORRECT ALT OF 2400 FT.

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.