EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Workload; Troubleshooting
Aircraft Equipment Problem Critical; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Landed in Emergency Condition; Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action; General Maintenance Action
Weather; Aircraft
Descending into ZZZ we descended quickly through an area of reported moderate to severe turbulence. In order to get down as quickly and as safely as possible the FO used the speed brakes in order to keep the speed down. Several moments after the speed breaks were selected to be retracted at around 12;000 MSL; I felt the airplane begin to roll. I looked at the panel as we were IMC and saw we were in a 20-30 degree bank to the left. I think I asked the FO [First Officer] who was PM [Pilot Monitoring]; 'if he did that.' He said no and I already had my hands on the controls while turning off the autopilot. I stated 'I have the aircraft in order to make sure there was no confusion or simultaneous application of the controls.' I looked over at the trims and saw that the aileron was neutral. At this point I'm needing close to full deflection to bring the plane back to level and then around half deflection to keep the wings level. As this is happening we get a SPOILER FAIL EICAS message and I realize it's actually the left spoiler that failed to retract causing the left roll. I called for the QRH and as the FO was getting the QRH out; the rolling tendency stopped and I was able to regain control and fly the aircraft by hand. There was no altitude deviation; as we were in a descent to 11;000 MSL; only a heading deviation of about 30 degrees to the left (we had been assigned direct the field). This deviation wasn't an issue as ATC had us turn left anyway for vectors to the ILS. Even though the failure had gone away; we ran the QRH anyway completely through. We requested priority handling as well after we finished running the QRH. The FO handled the situation extremely well and completed all necessary items in the QRH as well as finishing the descent checklist. We made a stable ILS approach and taxied off uneventfully. Spoiler failed to retract.
EMB-145 Captain reported failure of left spoiler to retract during approach.