MD-83
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Training / Qualification
Ground Excursion Taxiway; Inflight Event / Encounter Loss Of Aircraft Control
General Maintenance Action
Weather; Human Factors; Airport
During the approach the visibility was fluctuating and the Approach Control and Tower were updating the visibility and RVR. The braking action was reported as 'fair.' At about 300 to 400 FT above the minimums the First Officer called approach lights in sight. I continued the approach. At about 200 FT above minimums I had the approach lights; runway lights and runway in sight. At this point I disconnected the autopilot and the autothrottles and continued the descent. We landed; the spoilers deployed; the autobrakes engaged and I deployed the reverser's. We slowed to below 60 KTS; and I started braking manually; disconnecting the autobrakes below 60 KTS. We continued to slow the aircraft on the runway. As we approached Taxiway H1 at a slow rate; I used the tiller to guide the aircraft onto the taxiway with a right turn. During the initial turn off the runway; the aircraft responded normally to the tiller and brakes. About halfway through the turn; I felt the aircraft's momentum moving in a straight line; while the tiller was turned to the right. At this point; the aircraft appeared to not be responding to either tiller or brake inputs. As the aircraft approached the left side of the taxiway; and I was attempting to turn to the right; the First Officer questioned whether we were going to make the turn or not. I indicated that I didn't think the aircraft was responding; and shortly after that the nose gear exited the taxiway off the left side. We came to a stop and requested assistance from our ground operations. Our nose wheel and left main gear were in the grass; the right main gear were still on Taxiway H1. In adverse weather conditions; taxiways should be plowed and sanded.
It was a normal landing with flaps 40 and medium autobrakes. After turning on Taxiway Hotel 1 Tower asked for a in flight report. Part way through the report I noticed horizontal movement of the aircraft on the taxiway. Exact words I don't recall but I questioned the Captain on the horizontal movement which she then responded that she had negative control response. At that time the nose gear exited the taxiway to the left; the left main gear was slightly off but touched the taxiway. The right main stayed on the taxiway. After we came to a full stop we requested help from company and local facilities.
MD83 flight crew reports sliding off a taxiway while exiting the runway in light snow. Runway braking action was reported as fair.