Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness; Distraction
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Returned To Gate
Human Factors
Prior to pushback; I had removed a can of water from the wall side cup holder so I could put a cup of coffee there and set the can near the nose wheel tiller. I had planned on moving the can; but began a conversation with the Agent; my First Officer; and the Flight Attendant Crew. Unfortunately; I never moved the can and we accomplished our checklists; completed our pushback and engine start duties; and cleared the Ground Crew off after both engines started. We completed our After Start checklists and called for taxi. We were given a left turn out to taxi to the departure runway. I attempted to turn the tiller left and added power but the tiller wouldn't turn. I attempted to turn the tiller right and had full turn authority. I attempted three more times to turn the tiller left but to no avail. We asked the Ground Crew to come back out to the plane and check that the nose gear pin had been removed even though we were sure we saw them take it with them when they departed the plane with the tug. The Tug Driver checked the nose wheel area and assured us with hand signals that the nose gear pin had been removed. I then attempted once more to turn the tiller left and again; it would not turn. We then asked and received clearance to return to the gate; which we did. We elected to taxi slowly back in as we were in a straight line to the gate area and wouldn't have to make any turns. Once we shut the engines down and informed Operations of the situation; the Tug Driver entered the cockpit and told us what that everything looked normal to him in the nose wheel well. I attempted once more to turn the tiller left before I was going to call Dispatch for a patch to Maintenance Control when my hand slid off the tiller slightly and came in contact with the can of water I had repositioned some 20 minutes prior. I removed the can from under the tiller and the tiller moved freely. We talked to Dispatch about what our procedures were for departing and if they needed new paperwork. They informed us they didn't; our Agent cleared the gate return times and we pushed back; taxied out; and took off without incident.
A B737 Captain set a water can next to the steering tiller and after taxi out was unable to steer so returned to the gate where he found the water can; removed it and regained full steering control.