Narrative:

On taxi out; tower sequenced our airplane behind a boeing 757 for departure. The 757 was cleared for takeoff and we were instructed line up and wait. I asked the first officer if there was a crosswind for wake turbulence avoidance. He told me the winds were from the right at 3 knots. Tower wanted us off the ground quickly because an aircraft behind us was on short final for the same runway. The controller cleared us for takeoff just as the boeing 757 rotated off the runway in front of us. On climb out at 700 AGL; we hit the wake turbulence from the boeing 757 while in IMC. I pitched the nose down and stopped the climb to get out of the vortex. Once control of the aircraft was stabilized; I notified air traffic control of the event. There were no further disruptions for the remainder of the flight. Several threats came about during this event. The first was the close departure proximity behind a heavy aircraft. The second was the tower controller's goal to get as many airplanes off the ground in a short span of time to make the departures more efficient. And third was the aircraft behind us on short final pressuring us to takeoff immediately. My intuition told [me] this may happen when I asked the first officer if there was any crosswind to push the vortex out of our path; but I took the chance anyway to appease the controller and hoped for the best. Next time I will hold short of the runway and tell the controller I need more distance from the heavy aircraft. I will deny the takeoff clearance.

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Original NASA ASRS Text

Title: CRJ-900 Captain reported a wake vortex encounter at 700 feet AGL departing MSP when he was sequenced closely behind a departing B757.

Narrative: On taxi out; tower sequenced our airplane behind a Boeing 757 for departure. The 757 was cleared for takeoff and we were instructed line up and wait. I asked the first officer if there was a crosswind for wake turbulence avoidance. He told me the winds were from the right at 3 knots. Tower wanted us off the ground quickly because an aircraft behind us was on short final for the same runway. The controller cleared us for takeoff just as the Boeing 757 rotated off the runway in front of us. On climb out at 700 AGL; we hit the wake turbulence from the Boeing 757 while in IMC. I pitched the nose down and stopped the climb to get out of the vortex. Once control of the aircraft was stabilized; I notified air traffic control of the event. There were no further disruptions for the remainder of the flight. Several threats came about during this event. The first was the close departure proximity behind a heavy aircraft. The second was the tower controller's goal to get as many airplanes off the ground in a short span of time to make the departures more efficient. And third was the aircraft behind us on short final pressuring us to takeoff immediately. My intuition told [me] this may happen when I asked the first officer if there was any crosswind to push the vortex out of our path; but I took the chance anyway to appease the controller and hoped for the best. Next time I will hold short of the runway and tell the controller I need more distance from the heavy aircraft. I will deny the takeoff clearance.

Data retrieved from NASA's ASRS site 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.