Flight crew reported a taxiway excursion on taxi to the gate. Nil braking effectiveness on icy taxiway.
Synopsis
Flight crew reported a taxiway excursion on taxi to the gate. Nil braking effectiveness on icy taxiway.
Narrative
During flight from ZZZ1 to ZZZ; we were given landing clearance for a visual approach to Runway XX. Runway condition codes were 5/5/5. A normal approach to landing with good braking action and dry runway was made. We were instructed to roll to the end and exit at Taxiway X. I slowed aircraft and taxied off the runway onto Taxiway X where we were instructed to taxi north on X by Tower and taxi to the terminal. Taxiway X was dry ad we taxied at approximately 5 kts. We made a right hand turn onto Taxiway Y. As I initiated the right turn; I felt the aircraft begin to slide toward the left. Deflected tiller and right pedal full while simultaneously braking. Aircraft began a slow slide toward side of Taxiway Y. Left main mount departed the lined portion of the taxiway and came in contact with the snowbank as did the nose wheel and came to a stop. I immediately set the parking brake and informed Tower we may be off the taxiway and we required a tow. We then contacted Operations and ZZZ Maintenance and they were dispatched to tow the aircraft. The county personnel salted the route so a tug could remove the aircraft. Maintenance instructed us to shut down both engines to the APU and they then towed us to the gate. Passengers departed the aircraft normally via jet bridge.Icy taxiway with nil braking action on it was the reason the aircraft slid.Obtain updated taxiway information prior to taxiing in inclement weather.
Second reporter narrative
Aircraft landed on Runway XX. Tower gave instructions to continue and exit Runway XX at Taxiway X. After exiting Runway XX at X we completed the after landing checklist and continued taxiing via X. Tower gave instructions to remain on Tower frequency and continue taxiing to the gate. We continued our taxi towards the gate via Taxiway X. We made a right hand turn onto Taxiway Y and began sliding. The momentum of the aircraft took the left main gear off Taxiway Y and into a nearby snowbank. We came to a stop and notified the Tower. We then spoke with Operations and Maintenance who advised us that we would be tugged to the gate. We waited for Maintenance to tug us to the gate where we parked the aircraft.Ice on Taxiway Y. Braking action nil.Confirm field conditions are updated with Tower/Ground Control. Although we were cautious you can never be too careful.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.