Narrative:

When departing from cos airport the morning of jul/sun/93, I made an error in setting the altimeter which resulted in my altitude being 600 ft higher than it would have been with the correct setting. When I leveled off at my assigned altitude of 9000 cos departure control asked me for an altitude verification which was 9000. He then asked me to set the altimeter to 30.30 and give him another reading which was 9600 ft. I then informed him I would make the correction to my assigned altitude immediately. There was no further incident and no other traffic involved. I later analyzed how I had set the altimeter on the ground in cos and how I made the error. The barometric pressure was quite low (29.74) when we arrived in the springs on thur afternoon. This was my first experience with an airport with this high an altitude. When I reset to ground elevation on sun morning, I thought I set the correct figure but I didn't account for the big swing in barometric pressure and adjusted the large hand (rather than the correct small hand) to slightly past the 6. This set the altimeter at 5600 instead of 6183. As I was lifting off, I noticed the altimeter read about 5800 and thought I had noticed the altimeter read about 5800 and thought something was wrong, but then didn't remember to get a correct setting from departure. This has made me realize how easy it is to make an error like this, especially in a new area. In the future, I will check both the ground elevation and the barometric pressure to guard against this error.

Related reports:

Google
 

Original NASA ASRS Text

Title: ALT BUST.

Narrative: WHEN DEPARTING FROM COS ARPT THE MORNING OF JUL/SUN/93, I MADE AN ERROR IN SETTING THE ALTIMETER WHICH RESULTED IN MY ALT BEING 600 FT HIGHER THAN IT WOULD HAVE BEEN WITH THE CORRECT SETTING. WHEN I LEVELED OFF AT MY ASSIGNED ALT OF 9000 COS DEP CTL ASKED ME FOR AN ALT VERIFICATION WHICH WAS 9000. HE THEN ASKED ME TO SET THE ALTIMETER TO 30.30 AND GIVE HIM ANOTHER READING WHICH WAS 9600 FT. I THEN INFORMED HIM I WOULD MAKE THE CORRECTION TO MY ASSIGNED ALT IMMEDIATELY. THERE WAS NO FURTHER INCIDENT AND NO OTHER TFC INVOLVED. I LATER ANALYZED HOW I HAD SET THE ALTIMETER ON THE GND IN COS AND HOW I MADE THE ERROR. THE BAROMETRIC PRESSURE WAS QUITE LOW (29.74) WHEN WE ARRIVED IN THE SPRINGS ON THUR AFTERNOON. THIS WAS MY FIRST EXPERIENCE WITH AN ARPT WITH THIS HIGH AN ALT. WHEN I RESET TO GND ELEVATION ON SUN MORNING, I THOUGHT I SET THE CORRECT FIGURE BUT I DIDN'T ACCOUNT FOR THE BIG SWING IN BAROMETRIC PRESSURE AND ADJUSTED THE LARGE HAND (RATHER THAN THE CORRECT SMALL HAND) TO SLIGHTLY PAST THE 6. THIS SET THE ALTIMETER AT 5600 INSTEAD OF 6183. AS I WAS LIFTING OFF, I NOTICED THE ALTIMETER READ ABOUT 5800 AND THOUGHT I HAD NOTICED THE ALTIMETER READ ABOUT 5800 AND THOUGHT SOMETHING WAS WRONG, BUT THEN DIDN'T REMEMBER TO GET A CORRECT SETTING FROM DEP. THIS HAS MADE ME REALIZE HOW EASY IT IS TO MAKE AN ERROR LIKE THIS, ESPECIALLY IN A NEW AREA. IN THE FUTURE, I WILL CHK BOTH THE GND ELEVATION AND THE BAROMETRIC PRESSURE TO GUARD AGAINST THIS ERROR.

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.