A CL65RJ flight crew descends below the assigned altitude when they receive and set the wrong altime...

Attributes
ACN	405490
Time
Date	199806
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dsm
State Reference	IA
Altitude	msl bound lower : 10000 msl bound upper : 11000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp tracon : dsm
Operator	common carrier : air carrier
Make Model Name	Challenger CL604
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Route In Use	arrival other enroute : on vectors enroute airway : dsm
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 10000 flight time type : 350
ASRS Report	405490
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Being vectored for approach to runway 13L dsm, we were extraordinarily busy with thunderstorm avoidance. The copilot and I had set altimeters to 30.31 out of FL180. We had received ATIS, and been advised from ATC (ZMP) of 30.31. We were leveling at 11000 ft, our assigned altitude, and dsm approach advised us that they showed us at 10000 ft. They then said dsm altimeter is 29.31. Well, we were 1000 ft low, and approach asked us our altitude, and then told us to maintain 10000 ft MSL. I'm not sure who was wrong or right, but the late handoff from center (with very bad cells all around) sure didn't help us.

Original NASA ASRS Text

Title: A CL65RJ FLC DSNDS BELOW THE ASSIGNED ALT WHEN THEY RECEIVE AND SET THE WRONG ALTIMETER SETTING.

Narrative: BEING VECTORED FOR APCH TO RWY 13L DSM, WE WERE EXTRAORDINARILY BUSY WITH TSTM AVOIDANCE. THE COPLT AND I HAD SET ALTIMETERS TO 30.31 OUT OF FL180. WE HAD RECEIVED ATIS, AND BEEN ADVISED FROM ATC (ZMP) OF 30.31. WE WERE LEVELING AT 11000 FT, OUR ASSIGNED ALT, AND DSM APCH ADVISED US THAT THEY SHOWED US AT 10000 FT. THEY THEN SAID DSM ALTIMETER IS 29.31. WELL, WE WERE 1000 FT LOW, AND APCH ASKED US OUR ALT, AND THEN TOLD US TO MAINTAIN 10000 FT MSL. I'M NOT SURE WHO WAS WRONG OR RIGHT, BUT THE LATE HDOF FROM CTR (WITH VERY BAD CELLS ALL AROUND) SURE DIDN'T HELP US.

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.

A CL65RJ flight crew descends below the assigned altitude when they receive and set the wrong altimeter setting.