C182 pilot flying in icing conditions was advised by a ZSE controller that he was 300-400 ft above a...

Attributes
ACN	570026
Time
Date	200212
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zse.artcc
State Reference	WA
Altitude	msl bound lower : 12900 msl bound upper : 13150
Environment
Flight Conditions	IMC
Weather Elements	Ice
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse.artcc
Operator	general aviation : personal
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 38 flight time total : 6300 flight time type : 1800
ASRS Report	570026
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather
Independent Detector	atc equipment other atc equipment : radar/mode c aircraft equipment other aircraft equipment : altimeter other controllera other flight crewa
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Weather
Primary Problem	Weather

Narrative:

Picked up ice eastbound at 13000 ft, estimated 1/4 - 1/2 inch. Stayed with me rest of flight. Aircraft seemed to be less stable, perhaps up- and downdrafts. At one point, center gave me nearest altimeter setting 3 times, then told me I was 300 ft above assigned altitude. Altimeter showed 13050 ft. A second time they said I showed 400 ft high. My altitude showed 13150 ft. I flew remainder of flight at 12900 ft on altimeter. Further checks on return trip indicated all was normal with aircraft.

Original NASA ASRS Text

Title: C182 PLT FLYING IN ICING CONDITIONS WAS ADVISED BY A ZSE CTLR THAT HE WAS 300-400 FT ABOVE ASSIGNED ALT.

Narrative: PICKED UP ICE EBOUND AT 13000 FT, ESTIMATED 1/4 - 1/2 INCH. STAYED WITH ME REST OF FLT. ACFT SEEMED TO BE LESS STABLE, PERHAPS UP- AND DOWNDRAFTS. AT ONE POINT, CTR GAVE ME NEAREST ALTIMETER SETTING 3 TIMES, THEN TOLD ME I WAS 300 FT ABOVE ASSIGNED ALT. ALTIMETER SHOWED 13050 FT. A SECOND TIME THEY SAID I SHOWED 400 FT HIGH. MY ALT SHOWED 13150 FT. I FLEW REMAINDER OF FLT AT 12900 FT ON ALTIMETER. FURTHER CHKS ON RETURN TRIP INDICATED ALL WAS NORMAL WITH ACFT.

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.

C182 pilot flying in icing conditions was advised by a ZSE controller that he was 300-400 ft above assigned altitude.