Air carrier crew reported difficulties steering the aircraft during taxi in due to weather and taxi way conditions. Aircraft was subsequently towed in.
Synopsis
Air carrier crew reported difficulties steering the aircraft during taxi in due to weather and taxi way conditions. Aircraft was subsequently towed in.
Narrative
During slow taxi in after landing Rwy XX R; taxi off via Taxiway 1; Rwy XY R to Taxiway 2; cross Rwy XZ R then left on Taxiway 3; cleared to Taxiway 4; we left slats+flaps extended after landing due to encountering patchy contamination during landing rollout and along this assigned taxi route. Just after successfully negotiating the left turn from Taxiway 2 onto Taxiway 3; taxi speed was still quite slow. I could see increasing amounts of slushy buildup as we approached the taxiways near the terminal area so was trying to be very careful and taxiing slowly. Upon initiating the right turn around the taxiway Taxiway 3 bend to southbound. I experienced a lack of steering response to tiller inputs and the aircraft continued straight ahead. There was no nosewheel feedback or scrubbing at all indicating the nosewheel had even rotated and that the aircraft was trying to turn; trajectory continued straight ahead. Braking was ineffective as well; so continuing to hold right tiller; I engaged reverse thrust to attempt to slow/stop; differential braking and differential reverse thrust to try to get the aircraft to turn. The aircraft did finally turn but had overshot the prepped slushy center part of the taxiway and came to a stop angled back towards the center of the taxiway; but with left side/gear in the snow to the left of the embedded taxiway edge lights. With snow covered sides of the taxiway and infield could not discern where the edge of the paved surface was; so was unsure whether the left gear (and/or nose gear) had departed the taxiway. I set the parking brake; and asked the FO to inform Ground that we would need an inspection before continuing. At this time we both recognized an ECAM for Eng 2 FAIL; and briefly discussed the situation. Suspecting a compressor stall during the low-speed reverse thrust use; and possible icy/FOD ingestion or damage; we agreed that the best course of action would be to secure the engine (fuel lever off) and not restart it. Airfield ops completed their inspection and informed us that no gear had departed the paved surface and no damage apparent to the aircraft or engines or the embedded taxiway lights. Unable to taxi on #1 engine only; we then informed Ground we would need a tow-in; and coordinated appropriately with Company personnel. Tow-in etc was subsequently uneventful; although noticed that taxiway 3 slush contamination was significantly worse on the southbound portion. After shutdown we pulled the flight data and CVR recorder circuit breakers to preserve data and wrote up the loss of directional steering and #2 engine failure. Maintenance did check out the NWS steering system afterwards and it was signed off as normal. The #2 engine was borescoped and run; and exhibited no signs of damage. All systems functioned normally on return flight that we operated out that night.Cause: Contaminated taxiways; with increasing heaviness approaching the terminal area and at the taxiway 3 curve. What had been adequately slow taxi/turning speeds to that point were still not slow enough to successfully negotiate that turn. Recognized during post-event ASAP analysis: Having lined up with a nearly direct light tailwind approaching that bend may have contributed to insidious groundspeed creep; and possibly an aft landing CG degrading nosewheel effectiveness. Neither of those factors adversely affected handling during the earlier taxi turns. Suggestions: Better airfield clearing of contamination at known taxiway bends and intersections. Extremely slow taxi speed to compensate for poor conditions. Tow-in in lieu of taxi.
Second reporter narrative
We landed XX R in ZZZ uneventfully; conditions were VFR and I was PF. The runway was NOTAMed condition code 5/5/5 due to slush and deicing fluid. Once the airplane was slowed to a taxi speed we transferred aircraft control and were instructed to exit Taxiway 1; join XY R; and hold short of XX L. We complied with the instructions and discussed not retracting the flaps due to the contaminated runway but held the after landing checklist until workload decreased and clear of the runway. Shortly after clearing XX R we were cleared to cross XX L and join Taxiway 2 short of XZ R. Once cleared to cross XZ R we were cleared to taxi Taxiway 3; Taxiway 4 to the ramp. After making multiple large left turns up until this point without issue; including turns above 90degrees; the airplane then did not respond going into the right turn on taxiway 3. The Captain recognized the aircraft's failure to respond using Nose Wheel Steering and differential braking then used reverse thrust to regain control of the airplane and avoid departing the prepared surface. Once; the aircraft came to a stop it was apparent that the #2 engine had failed; and ECAM protocol was executed to secure the engine. The airplane was brought to a stop and an inspection crew was requested to assess the airplane; the airplane did not depart the pavement or have any damage. However; we did not restart the #2 engine due to possible FOD and therefore requested to be towed to parking.Cause: It is unclear whether the failure to maintain directional control was due to the taxiway contamination or if it was due to failure of the nose wheel steering. It is worth noting that when the Airport Ops inspection crew assessed the situation they mentioned that it did not look like the deviation was caused by sliding because the nose wheel never turned according to the track in the slush. Lastly; from my perspective it appeared that we taxiing at a conservative rate and had just exited a 90 degree left turn.Suggestions: It is unclear if this was a system failure or excessive speed while taxiing. However; as a crew we discussed a slower rate of taxi may have helped and more emphasis on the cold weather procedures.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.