Narrative:

Conditions: ramp and taxiways covered with ice; packed snow and loose snow. During taxi out I started a 90 degree turn from taxiway H to P. Halfway through the turn; at a speed of 6 knots; the nose wheel steering failed completely and the nose wheel went to 0 degrees by itself and the aircraft was headed straight toward the edge of the taxiway (with a snow bank just past the edge of the taxiway). I had to immediately apply full brakes to stop the aircraft from departing the paved taxiway surface. The aircraft came to an abrupt stop approximately 10 feet from the edge of the taxiway. After the aircraft was stopped; I heard the master caution tone and saw an amber ECAM message displayed: 'wheel north/west strg fault'. I also saw an amber message 'north/west strg disc' displayed in the memo area and 'steering' displayed in amber on the lower ECAM wheel page. I notified ground control we were unable to move and requested a tow back to the gate from maintenance. I then had the first officer refer to the flight manual irregular procedures. The flight manual states that if the fault occurs on the ground; you can do one system fault reset. The first officer then read the system reset for that fault which states you must get approval from maintenance control to do the reset. I then called maintenance control and the controller told me not to reset the fault but to leave it as it was because this aircraft had a previous write-up for the same problem and would need to be checked out by maintenance. The aircraft was towed back to the gate and maintenance had me turn the antiskid nosewheel steering switch from on to off; then back on. The ECAM messages then went away. The maintenance technician told me he thought there was a problem with the nose wheel steering control box; possibly from ice or water inside of it. I told operations we would either need to get this repaired or we would need a replacement aircraft. Operations told me they had another aircraft available for us so I decided to take that aircraft to avoid any further delays. As I was leaving the plane with the nose wheel steering problem; I was approached by a maintenance supervisor. He told me I could take the original aircraft now since the ECAM message had been erased by cycling the antiskid nosewheel steering switch. I explained to him that I would not be able to take the original plane until it was repaired because of the history of this aircraft; with a previous write-up of the same problem; and because of the severity of this nose wheel steering failure. He tried to persuade me to take this plane as is; stating that it had only been written up once before for the same problem. When I said that I was not comfortable doing that; he asked me to call dispatch and refuse the aircraft. I called dispatch and refused the aircraft as requested by the maintenance supervisor. I am very concerned about this situation for two reasons: (1) this was a very serious near mishap. If I had not immediately taken aggressive action to stop the aircraft movement; the plane would have departed the taxiway into a snow bank and caused significant damage to the engines; landing gear; airframe and possibly even passenger injury. If this failure of the nose wheel steering occurred when exiting a runway at 60 knots; it could be a disaster. (2) I felt pressured by the maintenance supervisor to take a bad aircraft. Rather than find the cause of the failure in the first place; he wanted to just reset the system and have me fly it as is. By telling me I had to formally 'refuse' the aircraft with dispatch; it gives the wrong impression that I was refusing an airworthy aircraft. I may be fairly new to the A320; but I am not a new captain. Under no circumstances will I fly an aircraft that I feel is unsafe. This plane was unsafe to fly.

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Original NASA ASRS Text

Title: Following the loss of nosewheel control on taxi out; an A319 flight crew refused to accept the aircraft for service because this was the second instance of such a loss with no substantive maintenance investigation.

Narrative: Conditions: ramp and taxiways covered with ice; packed snow and loose snow. During taxi out I started a 90 degree turn from taxiway H to P. Halfway through the turn; at a speed of 6 knots; the nose wheel steering failed completely and the nose wheel went to 0 degrees by itself and the aircraft was headed straight toward the edge of the taxiway (with a snow bank just past the edge of the taxiway). I had to immediately apply full brakes to stop the aircraft from departing the paved taxiway surface. The aircraft came to an abrupt stop approximately 10 feet from the edge of the taxiway. After the aircraft was stopped; I heard the master caution tone and saw an amber ECAM message displayed: 'WHEEL N/W STRG FAULT'. I also saw an amber message 'N/W STRG DISC' displayed in the memo area and 'STEERING' displayed in amber on the lower ECAM wheel page. I notified Ground Control we were unable to move and requested a tow back to the gate from Maintenance. I then had the First Officer refer to the flight manual irregular procedures. The flight manual states that if the fault occurs on the ground; you can do one system fault reset. The First Officer then read the system reset for that fault which states you must get approval from Maintenance Control to do the reset. I then called Maintenance Control and the Controller told me NOT to reset the fault but to leave it as it was because this aircraft had a previous write-up for the same problem and would need to be checked out by Maintenance. The aircraft was towed back to the gate and Maintenance had me turn the Antiskid Nosewheel Steering switch from ON to OFF; then back ON. The ECAM messages then went away. The Maintenance Technician told me he thought there was a problem with the nose wheel steering control box; possibly from ice or water inside of it. I told Operations we would either need to get this repaired or we would need a replacement aircraft. Operations told me they had another aircraft available for us so I decided to take that aircraft to avoid any further delays. As I was leaving the plane with the nose wheel steering problem; I was approached by a Maintenance Supervisor. He told me I could take the original aircraft now since the ECAM message had been erased by cycling the Antiskid Nosewheel Steering switch. I explained to him that I would not be able to take the original plane until it was repaired because of the history of this aircraft; with a previous write-up of the same problem; and because of the severity of this nose wheel steering failure. He tried to persuade me to take this plane as is; stating that it had only been written up once before for the same problem. When I said that I was not comfortable doing that; he asked me to call Dispatch and refuse the aircraft. I called Dispatch and refused the aircraft as requested by the Maintenance Supervisor. I am very concerned about this situation for two reasons: (1) This was a very serious near mishap. If I had not IMMEDIATELY taken aggressive action to stop the aircraft movement; the plane would have departed the taxiway into a snow bank and caused significant damage to the engines; landing gear; airframe and possibly even passenger injury. If this failure of the nose wheel steering occurred when exiting a runway at 60 knots; it could be a disaster. (2) I felt pressured by the Maintenance Supervisor to take a bad aircraft. Rather than find the cause of the failure in the first place; he wanted to just reset the system and have me fly it as is. By telling me I had to formally 'refuse' the aircraft with Dispatch; it gives the wrong impression that I was refusing an airworthy aircraft. I may be fairly new to the A320; but I am not a new Captain. Under no circumstances will I fly an aircraft that I feel is unsafe. This plane was unsafe to fly.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.