Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Deviation - Speed All Types; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Took Evasive Action
Environment - Non Weather Related; Procedure
ATC cleared our aircraft for takeoff right behind an EMB-170; directing us to maintain visual separation with the traffic. We were taking off on Runway 1 in DCA. While climbing over the Potomac River to intercept the 328 DCA radial; at approximately 500 FT; we encountered significant wake turbulence. The wake turbulence triggered the stick shaker and we briefly heard the warbler tone. We were on our flight director climb pitch and speed with takeoff power set; approximately 91% N1 when incident took place. I immediately reduced pitch and all stall warnings ceased. This reduction in pitch also removed the aircraft from the wake turbulence. After allowing the aircraft to accelerate above speed at which the incident took place I continued the climb. The event happened due to the close spacing of departures from DCA. More spacing should probably be given by ATC for EMB-170 aircraft which are considered RJ's but seem to be creating significant wake turbulence.
CRJ-200 Captain encountered wake vortex on departure from DCA in trail of an EMB-170. Reporter stated in trail requirements behind the EMB-170 should be increased.