Narrative:

We were cleared to taxi into position and hold on 22L at ord. Shortly before the preceding airbus 319/320 rotated; we were cleared for takeoff. We completed the takeoff check and commenced the takeoff roll.after rotation; around the time the first officer called 'positive rate' we encountered the wake of the preceding aircraft. While the wake seemed to impart no change to pitch or roll attitude that could not be easily countered with control yoke inputs; there was a sharp 'bump' that must have momentarily increased load factor. The stall protection system shaker activated for a short time (probably less than a second). Immediately afterward; we were clear of the wake turbulence.the event was so sudden; and of such brief duration; that it was over before I could think to make 'standard' sps activation callouts. My first officer related to me; on taxi out; that he previously had a similar shaker activation event on the same runway during an encounter with airbus wake turbulence. Since we were behind an E170 at that moment; I made no mental note regarding the impending takeoff. We were then 'sent to the front of the line' to takeoff behind the airbus. At that time I thought the story he related was a 'freak' event. I did not consider the wake turbulence of a narrow-body airbus to be a threat; and was very surprised to have encountered such a significant event from such an aircraft. Additionally; the high-volume and fast pace of operations at ord might have made me reluctant to have asked for further spacing from preceding aircraft; had I thought to.

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Original NASA ASRS Text

Title: CRJ-200 on departure encountered turbulence from preceding departing A320. Reporter was not expecting said turbulence.

Narrative: We were cleared to taxi into position and hold on 22L at ORD. Shortly before the preceding Airbus 319/320 rotated; we were cleared for takeoff. We completed the takeoff check and commenced the takeoff roll.After rotation; around the time the First Officer called 'positive rate' we encountered the wake of the preceding aircraft. While the wake seemed to impart no change to pitch or roll attitude that could not be easily countered with control yoke inputs; there was a sharp 'bump' that must have momentarily increased load factor. The Stall Protection System Shaker activated for a short time (probably less than a second). Immediately afterward; we were clear of the wake turbulence.The event was so sudden; and of such brief duration; that it was over before I could think to make 'standard' SPS activation callouts. My First Officer related to me; on taxi out; that he previously had a similar shaker activation event on the same runway during an encounter with Airbus wake turbulence. Since we were behind an E170 at that moment; I made no mental note regarding the impending takeoff. We were then 'sent to the front of the line' to takeoff behind the Airbus. At that time I thought the story he related was a 'freak' event. I did not consider the wake turbulence of a narrow-body Airbus to be a threat; and was very surprised to have encountered such a significant event from such an aircraft. Additionally; the high-volume and fast pace of operations at ORD might have made me reluctant to have asked for further spacing from preceding aircraft; had I thought to.

Data retrieved from NASA's ASRS site as of April 2012 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.