Narrative:

Descending on the sadde arrival we began receiving vectors for the visual for runway 24R into lax with a speed assignment of 180 KTS. Socal approach had descended us below 7;000 ft and advised us traffic to follow; a boeing 777 at our 3 o'clock. Both [the] captain and I saw the 777 right away and notified approach of this. At this point approach gave us a base leg turn; followed by clearing us for the visual runway 24R. Since we had been cleared for the visual approach I spun in an intercept heading of 220; followed by ATC assigning heading 230 to intercept. At this point we were leveling at 2200 ft. As the localizer became alive I noticed we were on about a 12 mile final when the approach controller stated; 'speed 160 if you like.' this confused both [the] captain and myself because we had never been told how fast the preceding 777 was traveling; if we were flying faster than the 777; or how far ahead the 777 was. At this point we had flown into the wake of the heavy 777. This caused the airplane to bank right to roughly 45-60 degrees. Without hesitation both the captain and I grabbed the controls; disconnected the auto pilot; and reestablished straight and level flight. Once re-arming the auto pilot we captured the localizer and glide path for the visual for runway 24R still outside the final approach fix. While in the recovery and configuring for landing; the master caution had been silenced due to high work load. It was not until just before '1000 ft instruments normal' call that [the] captain noticed that we had 3 EICAS caution messages; (windshear fail; aoa limit fail; shaker anticipated). At this point [the] captain called for a GA (go-around) and we executed the GA per sops. Once established in the GA [the] captain assigned control of the aircraft and radios to myself while he ran the QRH for the 3 EICAS messages we had received. The windshear fail; and aoa limit fail check list ended with them just being crew awareness messages while the shaker anticipated messages led to a new landing configuration with landing data. Once we had this all figured out with new landing data for the new landing configuration we continued with the climb check; descent check; and approach check before notifying ATC that we were ready to come back to lax for another landing attempt on runway 24R. This attempt occur normally; but during taxi into the gate the 3 EICAS caution messages cleared and 2 EICAS cyan messages of ads problems 2 and 4 fail appeared. Once at the gate with the flight officially ended [the] captain and I debriefed what had happened; the go around; all EICAS messages; and that no limitations had been exceeded in the last few moments of the flight. After an in-depth discussion with [the] captain I believe the root cause of this was a lack of communication between us as a crew and ATC as to our spacing and speed difference with the 777 that we were following. Neither the captain nor myself [queried] ATC as to how far behind or the speed difference between the two aircraft; and the confusing terminology that was used by ATC in by telling us to maintain 160 KTS if we wish were all causes.

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Original NASA ASRS Text

Title: EMB-175 flight crew reported encountering wake turbulence from a preceding B777 on arrival into LAX.

Narrative: Descending on the SADDE arrival we began receiving vectors for the visual for runway 24R into LAX with a speed assignment of 180 KTS. SOCAL Approach had descended us below 7;000 ft and advised us traffic to follow; a Boeing 777 at our 3 o'clock. Both [the] Captain and I saw the 777 right away and notified approach of this. At this point approach gave us a base leg turn; followed by clearing us for the visual runway 24R. Since we had been cleared for the visual approach I spun in an intercept heading of 220; followed by ATC assigning heading 230 to intercept. At this point we were leveling at 2200 ft. As the LOC became alive I noticed we were on about a 12 mile final when the approach controller stated; 'speed 160 if you like.' This confused both [the] Captain and myself because we had never been told how fast the preceding 777 was traveling; if we were flying faster than the 777; or how far ahead the 777 was. At this point we had flown into the wake of the heavy 777. This caused the airplane to bank right to roughly 45-60 degrees. Without hesitation both the Captain and I grabbed the controls; disconnected the auto pilot; and reestablished straight and level flight. Once re-arming the auto pilot we captured the localizer and glide path for the visual for runway 24R still outside the final approach fix. While in the recovery and configuring for landing; the master caution had been silenced due to high work load. It was not until just before '1000 ft instruments normal' call that [the] Captain noticed that we had 3 EICAS caution messages; (WINDSHEAR FAIL; AOA LIMIT FAIL; SHAKER ANTICIPATED). At this point [the] Captain called for a GA (go-around) and we executed the GA per SOPs. Once established in the GA [the] Captain assigned control of the aircraft and radios to myself while he ran the QRH for the 3 EICAS messages we had received. The WINDSHEAR FAIL; and AOA LIMIT FAIL check list ended with them just being crew awareness messages while the SHAKER ANTICIPATED messages led to a new landing configuration with landing data. Once we had this all figured out with new landing data for the new landing configuration we continued with the climb check; descent check; and approach check before notifying ATC that we were ready to come back to LAX for another landing attempt on runway 24R. This attempt occur normally; but during taxi into the gate the 3 EICAS caution messages cleared and 2 EICAS cyan messages of ADS PROBS 2 and 4 FAIL appeared. Once at the gate with the flight officially ended [the] Captain and I debriefed what had happened; the go around; all EICAS messages; and that no limitations had been exceeded in the last few moments of the flight. After an in-depth discussion with [the] Captain I believe the root cause of this was a lack of communication between us as a crew and ATC as to our spacing and speed difference with the 777 that we were following. Neither the Captain nor myself [queried] ATC as to how far behind or the speed difference between the two aircraft; and the confusing terminology that was used by ATC in by telling us to maintain 160 KTS if we wish were all causes.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.