During preflight, altimeter was set 1' too high resulting in altitude bust.

Attributes
ACN	82076
Time
Date	198802
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : hpn
State Reference	NY
Altitude	msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90
Operator	general aviation : corporate
Make Model Name	Helicopter
Flight Phase	cruise other ground : preflight
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 6500 flight time type : 3000
ASRS Report	82076
Person 2
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : undershoot non adherence : clearance non adherence other
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Before takeoff we were going through the checklist. When we came to the altimeter check, the first officer read the altimeter he heard on ATIS (30.56 in). During cruise ny approach called us and advised us to, 'maintain 3000'.' we both checked our altimeters and both instruments read 3000'. I then checked my radar altimeter and noted that it read 2000'. While I was checking my position in the charts, to see if we were over the bldgs in manhattan, approach called us again to advise, 'climb and maintain 3000'.' we responded with, 'say current altimeter setting.' approach said, '29.56.' we retuned our altimeters from 30.56 to 29.56, then climbed to 3000'. As best as we can tell, we incorrectly tuned in the 30.56 setting on the ground. A contributing factor to this error was that our altimeters were already set to 30.54 or .02 away from the incorrect 30.56 setting. Also, our aircraft are now equipped with the new style encoding altimeter with only the single analog needle for hundred feet increments. Thousand foot increments are given in a digital window that can be misread at even level altitudes. Example: one thousand feet just prior to all digits changing from 900'.

Original NASA ASRS Text

Title: DURING PREFLT, ALTIMETER WAS SET 1' TOO HIGH RESULTING IN ALT BUST.

Narrative: BEFORE TKOF WE WERE GOING THROUGH THE CHKLIST. WHEN WE CAME TO THE ALTIMETER CHK, THE F/O READ THE ALTIMETER HE HEARD ON ATIS (30.56 IN). DURING CRUISE NY APCH CALLED US AND ADVISED US TO, 'MAINTAIN 3000'.' WE BOTH CHKED OUR ALTIMETERS AND BOTH INSTRUMENTS READ 3000'. I THEN CHKED MY RADAR ALTIMETER AND NOTED THAT IT READ 2000'. WHILE I WAS CHKING MY POS IN THE CHARTS, TO SEE IF WE WERE OVER THE BLDGS IN MANHATTAN, APCH CALLED US AGAIN TO ADVISE, 'CLB AND MAINTAIN 3000'.' WE RESPONDED WITH, 'SAY CURRENT ALTIMETER SETTING.' APCH SAID, '29.56.' WE RETUNED OUR ALTIMETERS FROM 30.56 TO 29.56, THEN CLBED TO 3000'. AS BEST AS WE CAN TELL, WE INCORRECTLY TUNED IN THE 30.56 SETTING ON THE GND. A CONTRIBUTING FACTOR TO THIS ERROR WAS THAT OUR ALTIMETERS WERE ALREADY SET TO 30.54 OR .02 AWAY FROM THE INCORRECT 30.56 SETTING. ALSO, OUR ACFT ARE NOW EQUIPPED WITH THE NEW STYLE ENCODING ALTIMETER WITH ONLY THE SINGLE ANALOG NEEDLE FOR HUNDRED FEET INCREMENTS. THOUSAND FOOT INCREMENTS ARE GIVEN IN A DIGITAL WINDOW THAT CAN BE MISREAD AT EVEN LEVEL ALTS. EXAMPLE: ONE THOUSAND FEET JUST PRIOR TO ALL DIGITS CHANGING FROM 900'.

Data retrieved from NASA's ASRS site as of August 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.