Narrative:

While flying level over an open field, I performed a normal aileron roll. I decided to make a 180 degree turn and do another roll over the same field. I lost more airspeed than anticipated in the turn and started the roll at a lower than normal speed. When inverted, the nose dropped sharply and about 40 degrees off my initial heading. I lost several hundred ft, recovering about 500 ft AGL. The resulting flight path took me over several buildings at a much lower altitude than I would normally fly.

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Original NASA ASRS Text

Title: PLT OF AEROBATIC BIPLANE DOING LOW ALT AILERON ROLLS MISCALCULATES AIRSPD AND WHEN INVERTED DROPS SHARPLY GOING OFF HDG. RECOVERS ABOUT 500 FT AGL FLYING OVER SEVERAL BUILDINGS.

Narrative: WHILE FLYING LEVEL OVER AN OPEN FIELD, I PERFORMED A NORMAL AILERON ROLL. I DECIDED TO MAKE A 180 DEG TURN AND DO ANOTHER ROLL OVER THE SAME FIELD. I LOST MORE AIRSPD THAN ANTICIPATED IN THE TURN AND STARTED THE ROLL AT A LOWER THAN NORMAL SPD. WHEN INVERTED, THE NOSE DROPPED SHARPLY AND ABOUT 40 DEGS OFF MY INITIAL HDG. I LOST SEVERAL HUNDRED FT, RECOVERING ABOUT 500 FT AGL. THE RESULTING FLT PATH TOOK ME OVER SEVERAL BUILDINGS AT A MUCH LOWER ALT THAN I WOULD NORMALLY FLY.

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.