Narrative:

Told to fly a descent to 1000 ft by tower and to follow the river, then on course, as requested I had requested 3500 ft. So after the river I assumed I was cleared as filed up to 3500 ft. However, I misunderstood that he wanted me to ascend according to the airspace ceilings of the class B and not a clearance up to 3500 ft. After studying the chart I realized my mistake and have had it explained to me by a flight instructor. No evasive action was taken in this scenario. Next time I will reconfirm airspace and clrncs from ATC.

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Original NASA ASRS Text

Title: CESSNA 172 INADVERTENTLY ENTERS CLASS B AIRSPACE N-90.

Narrative: TOLD TO FLY A DSCNT TO 1000 FT BY TWR AND TO FOLLOW THE RIVER, THEN ON COURSE, AS REQUESTED I HAD REQUESTED 3500 FT. SO AFTER THE RIVER I ASSUMED I WAS CLRED AS FILED UP TO 3500 FT. HOWEVER, I MISUNDERSTOOD THAT HE WANTED ME TO ASCEND ACCORDING TO THE AIRSPACE CEILINGS OF THE CLASS B AND NOT A CLRNC UP TO 3500 FT. AFTER STUDYING THE CHART I REALIZED MY MISTAKE AND HAVE HAD IT EXPLAINED TO ME BY A FLT INSTRUCTOR. NO EVASIVE ACTION WAS TAKEN IN THIS SCENARIO. NEXT TIME I WILL RECONFIRM AIRSPACE AND CLRNCS FROM ATC.

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.