B757-200
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Distraction
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Unstabilized Approach
Flight Crew Returned To Clearance; Flight Crew Executed Go Around / Missed Approach
Environment - Non Weather Related; Procedure
As pilot flying and cleared and established on the ILS 36C at approximately 1650' we encountered severe wake turbulence from a 767 in front of us.  The airplane rolled to approximately 30 degrees un-commanded left angle of bank and we turned off the autopilot; followed by 30 degrees un-commanded angle of bank to the right.  Simultaneously the right yaw damper EICAS caution message illuminated.  We discontinued the approach and were given a right turn heading 090 and a climb to 3;000 feet.  We deviated altitude by approximately 270 feet.  We completed the yaw damper procedures per the QRH and did the other checklists for the follow-on ILS to 36C.  Severe wake turbulence from a preceding 767.  High work load environment with origin of event which occurred close to the ground. Larger separation between aircraft on IMC approaches.
I was pilot monitoring. We were established on the ILS 36C and had just intercepted the GS at 2;000 feet and as we crossed approximately 1;700 feet on the glide slope; the airplane abruptly banked to the left and right twice to approximately 30 degrees. There was a B767 5 miles ahead which flight path was above ours; which brought me to believe it was a severe wake turbulence encounter. The Captain and pilot flying disconnected the autopilot and executed a go-around. I informed Approach we needed to discontinue the approach due to 'wake turbulence' and Approach proceeded to assign us a right turn to a heading of 090 as well as 3;000 feet. While trying to maintain wings level to regain aircraft control; the Pilot Flying was able to start the climb while turning to the 090 heading. While hand flying the go-around procedure we received an 'R Yaw Damper' EICAS message and deviated from the assigned altitude by 270 feet. We both recognized the deviation as our workload increased. We returned to 3;000 feet; engaged the autopilot; and proceeded to get vector to execute the ILS 36C. We had jump seaters on board and made sure everybody was okay. The Captain elected to expand his perspective and called one of the jump seaters; a line check airman; to the flight deck to monitor the remainder of the flight. We continued the ILS 36C and landed safely. Severe wake turbulence encounter that was followed by an EICAS message 'R Yaw Damper' while in IMC. This high workload environment caused us to narrowly focus on the problem during the go-around and deviate from the assigned altitude by 270 feet. Larger separation from airplanes on IMC approach or proper altitude assignment to following aircraft.
B757 flight crew reported encountering 'severe' wake turbulence on approach to MEM in trail of a B767.