Narrative:

I took off at XA45 am and flew a banner along the I-76 expressway to where the river and expressway turn south toward the city. When I crossed the river the wind over north philadelphia also turned right towards center city, and the TCA (class B). I tried flying at 100 ft AGL to over 1000 ft AGL. None of the winds were blowing towards new jersey any more. (Nj is where our test balloons went.) I flew at 400-500 ft AGL (congested area) where the wind would steer me to building X. I knew there would be landing space there. The wind was very gentle and I landed on an empty parking access road behind the building. Pilot balloons sent up prior to flight showed I could overfly north philadelphia to new jersey. The lower winds changed by the time I reached north philadelphia. The winds aloft were always headed for downtown and the TCA. I should have realized that the lower winds might turn that way, during the flight. All I could do was use the new lower winds to get to a safe landing spot.

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Original NASA ASRS Text

Title: A BALLOON MOVES INTO CLASS B AIRSPACE AT PHL, PA. PLT VARIES ALT TO OBTAIN WIND THAT WILL DRIFT HIM IN DESIRED DIRECTION.

Narrative: I TOOK OFF AT XA45 AM AND FLEW A BANNER ALONG THE I-76 EXPRESSWAY TO WHERE THE RIVER AND EXPRESSWAY TURN S TOWARD THE CITY. WHEN I CROSSED THE RIVER THE WIND OVER NORTH PHILADELPHIA ALSO TURNED R TOWARDS CENTER CITY, AND THE TCA (CLASS B). I TRIED FLYING AT 100 FT AGL TO OVER 1000 FT AGL. NONE OF THE WINDS WERE BLOWING TOWARDS NEW JERSEY ANY MORE. (NJ IS WHERE OUR TEST BALLOONS WENT.) I FLEW AT 400-500 FT AGL (CONGESTED AREA) WHERE THE WIND WOULD STEER ME TO BUILDING X. I KNEW THERE WOULD BE LNDG SPACE THERE. THE WIND WAS VERY GENTLE AND I LANDED ON AN EMPTY PARKING ACCESS ROAD BEHIND THE BUILDING. PLT BALLOONS SENT UP PRIOR TO FLT SHOWED I COULD OVERFLY NORTH PHILADELPHIA TO NEW JERSEY. THE LOWER WINDS CHANGED BY THE TIME I REACHED NORTH PHILADELPHIA. THE WINDS ALOFT WERE ALWAYS HEADED FOR DOWNTOWN AND THE TCA. I SHOULD HAVE REALIZED THAT THE LOWER WINDS MIGHT TURN THAT WAY, DURING THE FLT. ALL I COULD DO WAS USE THE NEW LOWER WINDS TO GET TO A SAFE LNDG SPOT.

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.