Date: 201812
Local time of day: 1201-1800
Location: DCA.Airport, DC
Flight conditions: VMC
Light: Night
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZDC
ATC / advisory: Center ZDC
Second aircraft: B777 Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Regained Aircraft Control; General Maintenance Action; General Physical Injury / Incapacitation
Contributing factors: Procedure; Environment - Non Weather Related
Primary problem: Procedure

Narrative: While climbing around FL230; we encountered severe wake turbulence from a Boeing 777. The other aircraft was about 2000 feet above and 8 miles in front of us. At the time we had not been advised of the traffic by ATC and we had no idea it was a heavy aircraft. We had an almost direct tailwind. There was no turbulence during the climb and I had turned off the seatbelt sign. Both flight attendants and one passenger were standing at the time. One Flight Attendant was helping the standing passenger who was mobility challenged into the lavatory. She hit her head and later in the day began complaining of soreness in her back and side. The other Flight Attendant fell to the ground and was caught by a seated passenger. The standing passenger did not fall. The First Officer and I had been discussing the proximity of the other aircraft and the fact that there was not a crosswind to make the wake drift off course. We did not have enough time to determine that we may need to fly off course to avoid the wake. There was no information available to us to indicate that the other aircraft was a heavy Boeing 777. We flew into the wake turbulence as it drifted downward along our flight path. The 777 looked like it was on a SID from IAD. We were on a SID from DCA. The incident occurred shortly after both SIDs merged onto the airway system. There was chop for about 3 seconds before we hit the vortex. It was just enough time for me to say we were in his wake. Once we were in the vortex; the autopilot disconnected and the aircraft banked hard left. We were only in the vortex for a second or two but we were put in a 30-45 degree left bank instantly. After we had the airplane back under control; I notified ATC that we encountered severe wake turbulence and that it knocked both flight attendants down but that we did not have any injuries. I sent an ACARS to dispatch letting them know and asked them to advise Maintenance Control that we may need a severe turbulence inspection. Once on the ground; I contacted Dispatch via telephone and filed a report with the coordinator. We determined that the encounter matched the description of severe turbulence and Out Station Maintenance was called to perform a visual inspection of the aircraft. I also spoke to managers in [inflight services] and the Chief Pilot's office. We determined that the flight attendants should be removed from duty and replaced once back in DCA for medical evaluation. We often don't know when we are following a heavy aircraft and rely on ATC for nearly all of our wake turbulence separation. When we are below and behind a nearby heavy aircraft; it would be suggested for ATC to give us an off course vector. It may also be helpful for ATC to solicit wind information so they know if the wake might be a hazard.




Synopsis: CRJ-700 Captain reported encountering severe wake turbulence at FL230 after departing DCA in trail of a B777.