Narrative:

We were climbing out of cps northbound. We leveled off at 2500 ft. Class B started at 3000 ft. I noted to my instructor that it took us an awfully long time to climb to 2500 ft. After discussing that for 30 seconds or so, we figured out that due to a drastic pressure change from the day before that we set the altimeter 1000 ft low. Thus, making us actually at 3500 ft. We descended out of class B as quickly as possible. More thoroughness on my part would have prevented the problem.

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Original NASA ASRS Text

Title: SMA TRAINEE AND INSTRUCTOR PENETRATED STL CLASS B AIRSPACE.

Narrative: WE WERE CLBING OUT OF CPS NBOUND. WE LEVELED OFF AT 2500 FT. CLASS B STARTED AT 3000 FT. I NOTED TO MY INSTRUCTOR THAT IT TOOK US AN AWFULLY LONG TIME TO CLB TO 2500 FT. AFTER DISCUSSING THAT FOR 30 SECONDS OR SO, WE FIGURED OUT THAT DUE TO A DRASTIC PRESSURE CHANGE FROM THE DAY BEFORE THAT WE SET THE ALTIMETER 1000 FT LOW. THUS, MAKING US ACTUALLY AT 3500 FT. WE DSNDED OUT OF CLASS B AS QUICKLY AS POSSIBLE. MORE THOROUGHNESS ON MY PART WOULD HAVE PREVENTED THE PROB.

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.