EMB ERJ 190/195 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Environment - Non Weather Related; Procedure
The Captain was the pilot monitoring and I was the pilot flying. This was leg 3 of a 4 leg sequence. We were on the visual approach to Runway 01 DCA with an aircraft approximately 5 miles ahead on the same approach. We were configured Flaps 3 and stable at about 1800 feet. The aircraft quickly rolled left to about 20-30 degrees uncommanded. There was also a distinct buzz/vibration when this occurred. I immediately grabbed the controls and turned off the autopilot. I elected to leave the auto throttles on at that time. I rolled the aircraft level and continued the descent. The EICAS began flashing messages; the big ones being windshear fail; AOA Limit; Unreliable Airspeed and Stick Shaker Anticipated. There was a verbal transfer of aircraft control; I continued to fly the aircraft and the Captain ran the QRH. We determined that the airspeed was reliable but that the stall protection was an issue. We decided to bump up Vref by around 10kts and both felt it was safer to continue the approach rather than execute a go-around at that point. I continued the approach and we configured with gear and flaps 5; then I elected to turn the auto throttles off and fly the aircraft with no automation. The rest of the approach and landing were uneventful. We taxied to the gate and called Maintenance. This event was similar to a previous event I have had in the past from wake turbulence from a preceding aircraft. There was also a tailwind and the winds were about 5 kts. I'm not sure how we could do more to avoid this if it was wake turbulence. The preceding aircraft; an E-175; was about 5 miles ahead.
ERJ-190 F/O reported encountering wake turbulence on approach to DCA five miles in trail of an E175.