|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : hpn|
|Altitude||msl bound lower : 2000|
msl bound upper : 3000
|Controlling Facilities||tracon : n90|
|Operator||general aviation : corporate|
|Make Model Name||Helicopter|
|Flight Phase||cruise other|
ground : preflight
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 100|
flight time total : 6500
flight time type : 3000
|Function||flight crew : first officer|
|Qualification||pilot : instrument|
pilot : commercial
|Anomaly||altitude deviation : undershoot|
non adherence : clearance
non adherence other
|Independent Detector||other controllera|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
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.