Date: 201408
Location: ZZZ.Airport, US
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ZZZ; Tower ZZZ
Aircraft component: Main Gear
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Maintenance
When detected: Taxi
Result: Flight Crew Returned To Gate; General Maintenance Action
Contributing factors: Chart Or Publication; Aircraft; Human Factors
Primary problem: Human Factors

Narrative: We were number three for takeoff on RWY XXL when we received an urgent ACARS message and call from the Tower to return to the gate. We received clearance from Ground and headed back to Gate-XX for what we confirmed to be a Maintenance landing gear issue. After blocking in; I called Station Maintenance to get clarification and they had very little information. I then called the Dispatcher to get a connection with Maintenance Control. The Maintenance Controller was relatively brief in his explanation but it turned out to be a Mechanic that was concerned he had not fully completed work on a Main Landing Gear (MLG) rebuild that had been done a week and a half earlier in ZZZ2. He was concerned if 'all the parts were in place;' according to Maintenance Control. I then coordinated with Ramp Operations; ZZZ Maintenance; and Customer Service (C/S) on the issue and waited for the mechanics to complete their inspection (estimated time 15-30 minutes). They completed the work in approximately 25-30 minutes from blocking back in and the Lead Mechanic briefed us personally in the flight deck that all looked good; everything was in place; and the aircraft was good to go. He found that all the parts in question were in place and he would sign it off and send a new Maintenance Release. I then called to inform Ramp Operations whereby she informed me they had already swapped the aircraft for an A319 (from an A320) at Gate XY; and that the passengers were to be deplaned and moved. It took me no less than ten more minutes to debate with her and talk to her Supervisor explaining the absolute outrageousness of that decision since now our aircraft was signed-off and we were ready to close the door! After talking to the Supervisor; he agreed and we quickly closed the doors; received a new Maintenance Release and pushed back to head to ZZZ1. We departed with Flight Plan XYZ04 (after several aircraft changes; finally back to the original A320 aircraft) and Maintenance Release ZZZ August 2014. This entire incident is beyond baffling; and while I can certainly see that things can be missed; what appalls me more than anything is the fact that this aircraft flew for at LEAST one and a half weeks before this potential error was addressed. Thankfully the mechanics in ZZZ found everything in order; but what if they didn't?   What about all the subsequent flights since the gear change in ZZZ2?  This kind of thing cannot happen anywhere; least of all at our air carrier. This occurrence was absolutely unacceptable and should be researched to the fullest extent.




Synopsis: While in line for takeoff; an air carrier flight crew received an urgent message to return to gate. They were informed that a Mechanic was concerned he had not fully completed rebuild work approximately a week and a half earlier on their A320 Main Landing Gear (MLG). Captain very concerned about the number of flights flown and length of time before the maintenance error was addressed.