Narrative:

While on approach to runway 27L at ord; at approximately a 10 to 15 mile final; we encountered wake turbulence. We were on glide slope and slowing to 170 kts. Until the final approach fix as instructed by ATC. The wake turbulence resulted in an uncommanded roll to the right between 30 and 40 degrees. Upon the encounter the captain who was pilot flying disengaged the autopilot and leveled the wings and began to return to the desired flight path. Four EICAS caution messages were displayed: at fail; windshear fail; stall prot fail; and aoa limit fail. We waited a brief period to see if the messages would clear. They did not. At the captain's direction; I began to run the QRH for the displayed messages. While running the QRH checklist for stall prot fail which included entering new approach speeds; the captain realized that we were below 1;000 ft. AGL and not configured. We executed a go around. Initially we were told to level at 2;500 ft.; then instructed to turn toward the north and climb 5;000 ft. And expect ILS runway 27R. During this time; QRH items were completed and we returned for an uneventful landing runway 27R. ATC stated the largest aircraft ahead of us was an E175. Given the nature of the wake turbulence; we believe it is possible that we may have encountered a wake from heavier traffic to a parallel runway although we do not know for sure.as a recommendation; it may be prudent to execute a go around earlier in these circumstances. We allowed the aircraft to get below 1;000 ft. Prior to realizing that we were unstable while I was running the QRH. Given the added tasks created by the QRH checklist; it was easy to get behind the aircraft.

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Original NASA ASRS Text

Title: E170 flight crew reported that a possible wake turbulence encounter resulted in an unstabilized approach and a go around.

Narrative: While on approach to Runway 27L at ORD; at approximately a 10 to 15 mile final; we encountered wake turbulence. We were on glide slope and slowing to 170 kts. until the final approach fix as instructed by ATC. The wake turbulence resulted in an uncommanded roll to the right between 30 and 40 degrees. Upon the encounter the Captain who was Pilot Flying disengaged the autopilot and leveled the wings and began to return to the desired flight path. Four EICAS caution messages were displayed: AT FAIL; WINDSHEAR FAIL; STALL PROT FAIL; and AOA LIMIT FAIL. We waited a brief period to see if the messages would clear. They did not. At the Captain's direction; I began to run the QRH for the displayed messages. While running the QRH checklist for STALL PROT FAIL which included entering new approach speeds; the Captain realized that we were below 1;000 ft. AGL and not configured. We executed a go around. Initially we were told to level at 2;500 ft.; then instructed to turn toward the north and climb 5;000 ft. and expect ILS Runway 27R. During this time; QRH items were completed and we returned for an uneventful landing Runway 27R. ATC stated the largest aircraft ahead of us was an E175. Given the nature of the wake turbulence; we believe it is possible that we may have encountered a wake from heavier traffic to a parallel runway although we do not know for sure.As a recommendation; it may be prudent to execute a go around earlier in these circumstances. We allowed the aircraft to get below 1;000 ft. prior to realizing that we were unstable while I was running the QRH. Given the added tasks created by the QRH checklist; it was easy to get behind the aircraft.

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.