Narrative:

After push-back; we experienced a nose wheel steering (NWS) fault on initial taxi with a loss of steering. We stopped the aircraft; notified ground control; and performed the associated checklist for the fault. The system was restored by the procedure. We then taxied to a holding area and contacted dispatch and maintenance control to report 'system discrepancy after dispatch'. With dispatch concurrence; we continued taxiing but subsequently had a second NWS fault. At that point; we again stopped the aircraft; coordinated with ATC and ops/maintenance; and returned to the gate under tow. A logbook entry was made and after a consult with dispatch; we switched aircraft and continued on. Passengers were briefed throughout the process. Aircraft reportedly had prior history and maintenance printout showed bscu electrical anomaly.the quick reference handbook procedure for NWS fault is somewhat ambiguous as written. While the note at the top of the procedure allows a single reset of the system; the checklist procedure itself requires returning to the gate; presumably on the premise that the system did not reset. For clarity; it would be preferable to have it re-written in an 'if-then-else' scenario with the notes inserted at the appropriate places in the checklist. On a crowded taxiway with ground control nagging us; this was initially a source of confusion. It was only after mutual agreement with ops/maintenance that we continued taxiing.

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Original NASA ASRS Text

Title: An A319 Captain reported a nose wheel steering failure during taxi out. After a successful reset followed by a second failure the aircraft is towed to the gate. The aircraft had a history of similar faults.

Narrative: After push-back; we experienced a Nose Wheel Steering (NWS) fault on initial taxi with a loss of steering. We stopped the aircraft; notified Ground Control; and performed the associated checklist for the fault. The system was restored by the procedure. We then taxied to a holding area and contacted Dispatch and Maintenance Control to report 'system discrepancy after dispatch'. With Dispatch concurrence; we continued taxiing but subsequently had a second NWS fault. At that point; we again stopped the aircraft; coordinated with ATC and Ops/Maintenance; and returned to the gate under tow. A logbook entry was made and after a consult with Dispatch; we switched aircraft and continued on. Passengers were briefed throughout the process. Aircraft reportedly had prior history and maintenance printout showed BSCU electrical anomaly.The Quick Reference Handbook procedure for NWS fault is somewhat ambiguous as written. While the note at the top of the procedure allows a single reset of the system; the checklist procedure itself requires returning to the gate; presumably on the premise that the system did not reset. For clarity; it would be preferable to have it re-written in an 'if-then-else' scenario with the notes inserted at the appropriate places in the checklist. On a crowded taxiway with Ground Control nagging us; this was initially a source of confusion. It was only after mutual agreement with Ops/Maintenance that we continued taxiing.

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.