Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Deviation - Speed All Types; Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Environment - Non Weather Related; Procedure
Just after rotation; departing behind a DC-9 the aircraft was hit by wake. Moderate aileron forces were needed but the most concerning issue was a momentary stick shaker. The aircraft was and remained on speed V2 plus 15 knots as bugged; 166 knots. The numbers are certain as they were later checked. We were about 400 FT AGL at start of wake turbulence. There was a slight quartering tail wind. The report is mostly to catalog the event to hopefully avoid other wake events. Duration of event was very short.Cause may have been tail wind and separation being close; along with being right in the center of the wake due to being in trail. Better separation obviously helps avoid these problems.
The rotation speed and pitch attitude were standard. There was a slight tailwind (340 at 6 knots). The captain; who was flying; added the correct aileron and pitch to hold our altitude and gain airspeed while we climbed out.
CRJ-200 flight crew reported encountering wake turbulence in trail of a DC-9 departing ATL that resulted in a momentary stick shaker.