Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Returned To Gate; General Maintenance Action
Human Factors; Aircraft
After an extended on-gate delay we pushed. The ramp and taxiways were covered in ice and snow. Braking action reported as poor on these surfaces. The tug was not able to push us back as far as normal before it lost traction however it was far enough back to turn out with wing walkers.I checked braking action before we started the turn and it was poor; but acceptable. I felt the nose wheel steering was nil to poor (we later found out the steering was physically disconnected). Careful combination of differential thrust and braking was used to turn out and taxi the aircraft to the de-ice pad and runway.The only surface on the airport that was visible through the snow was the runway (which had the best traction). Once we were on the runway; we experienced severe nose wheel shimmy and returned to the gate. On a visual inspection of the nose wheel we found the torque link disconnected.Both the First Officer and I made the assumption that the icy ramp and taxiway were the reason for steering difficulty. We did not have any indication or message that the steering was inoperative (it was in fact working; just not connected to the tires). The First Officer did not find any issue with the torque link on the walk around. It was in fact extremely obvious once we returned to the gate. If the torque link was disconnected prior to push; I would be quite certain that the First Officer or ground crew would notice the large linkage bar hanging down. I suspect the linkage actually disconnected once I engaged the nose wheel steering system.
CRJ-700 Captain reported departing the gate with the nose wheel steering torque link disconnected.