B757-200 crew had altitude overshoot in dtw class east airspace.

Attributes
ACN	500220
Time
Date	200101
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : mizar
State Reference	MI
Altitude	msl bound lower : 11470 msl bound upper : 12000
Environment
Flight Conditions	IMC
Weather Elements	Snow Ice Turbulence
Light	Night
Aircraft 1
Controlling Facilities	tracon : d21.tracon
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	descent : vacating altitude descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : commercial pilot : multi engine
Experience	flight time last 90 days : 100 flight time total : 12000 flight time type : 5200
ASRS Report	500220
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 7000 flight time type : 2500
ASRS Report	499643
Events
Anomaly	altitude deviation : overshoot inflight encounter : weather inflight encounter other non adherence : clearance non adherence : company policies non adherence : published procedure other anomaly other
Independent Detector	atc equipment other atc equipment : radar other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We had just begun our final descent into dtw. I was the PNF. I started the descent checklist passing through FL180. About 1/2 way through the checklist, we both noticed the windshields iced over. We knew we had all of our ice protection on but the rate of accumulation took us by surprise. Less than 5 mins later, all the ice was gone. During that time we leveled off at 12000 ft, but we did not set our altimeters to the local setting 29.39. This mistake put us 400 ft low on the arrival. The ATC controller asked us to change xponders. We corrected the mistake, changed xponders, and continued on.

Original NASA ASRS Text

Title: B757-200 CREW HAD ALT OVERSHOOT IN DTW CLASS E AIRSPACE.

Narrative: WE HAD JUST BEGUN OUR FINAL DSCNT INTO DTW. I WAS THE PNF. I STARTED THE DSCNT CHKLIST PASSING THROUGH FL180. ABOUT 1/2 WAY THROUGH THE CHKLIST, WE BOTH NOTICED THE WINDSHIELDS ICED OVER. WE KNEW WE HAD ALL OF OUR ICE PROTECTION ON BUT THE RATE OF ACCUMULATION TOOK US BY SURPRISE. LESS THAN 5 MINS LATER, ALL THE ICE WAS GONE. DURING THAT TIME WE LEVELED OFF AT 12000 FT, BUT WE DID NOT SET OUR ALTIMETERS TO THE LCL SETTING 29.39. THIS MISTAKE PUT US 400 FT LOW ON THE ARR. THE ATC CTLR ASKED US TO CHANGE XPONDERS. WE CORRECTED THE MISTAKE, CHANGED XPONDERS, AND CONTINUED ON.

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.