C210 pilot suffers altitude deviation due to mis-setting altimeter.

Attributes
ACN	808071
Time
Date	200810
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl bound lower : 3700 msl bound upper : 4700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	general aviation : personal
Make Model Name	Cessna 120
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Experience	flight time last 90 days : 26 flight time total : 1200 flight time type : 988
ASRS Report	808071
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Weather Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During initial climb; ATC inquired about my assigned altitude to which I replied that I was assigned to 4000 ft; and currently climbing 3700 ft (estimated) to 4000 ft. ATC advised that they showed me above 4000 ft and asked me to confirm altimeter setting which they provided. After adjusting the altimeter setting; a descent was required to return to 4000 ft. Contributing factors: during preflight; I adjusted the altimeter to roughly to the airport altitude so that only small adjustments would be required after start-up using the airport ATIS information. I turned the indicator counterclockwise from about 600 ft to the airport altitude of 4000 ft. Unfortunately; it should have been turned clockwise; as it was now set at -960 ft. After start-up and obtaining the ATIS altimeter setting; I adjusted the tenths and hundredths in the altimeter; thus leaving it set at 28.97 instead of 29.97.

Original NASA ASRS Text

Title: C210 PLT SUFFERS ALT DEV DUE TO MIS-SETTING ALTIMETER.

Narrative: DURING INITIAL CLB; ATC INQUIRED ABOUT MY ASSIGNED ALT TO WHICH I REPLIED THAT I WAS ASSIGNED TO 4000 FT; AND CURRENTLY CLBING 3700 FT (ESTIMATED) TO 4000 FT. ATC ADVISED THAT THEY SHOWED ME ABOVE 4000 FT AND ASKED ME TO CONFIRM ALTIMETER SETTING WHICH THEY PROVIDED. AFTER ADJUSTING THE ALTIMETER SETTING; A DSCNT WAS REQUIRED TO RETURN TO 4000 FT. CONTRIBUTING FACTORS: DURING PREFLT; I ADJUSTED THE ALTIMETER TO ROUGHLY TO THE ARPT ALT SO THAT ONLY SMALL ADJUSTMENTS WOULD BE REQUIRED AFTER START-UP USING THE ARPT ATIS INFO. I TURNED THE INDICATOR COUNTERCLOCKWISE FROM ABOUT 600 FT TO THE ARPT ALT OF 4000 FT. UNFORTUNATELY; IT SHOULD HAVE BEEN TURNED CLOCKWISE; AS IT WAS NOW SET AT -960 FT. AFTER START-UP AND OBTAINING THE ATIS ALTIMETER SETTING; I ADJUSTED THE TENTHS AND HUNDREDTHS IN THE ALTIMETER; THUS LEAVING IT SET AT 28.97 INSTEAD OF 29.97.

Data retrieved from NASA's ASRS site as of May 2009 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.